To see the other types of publications on this topic, follow the link: Frobenius's theorem.
Dissertations / Theses on the topic 'Frobenius's theorem'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Frobenius's theorem.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Rosa, Ester Cristina Fontes de Aquino 1979. "A função hipergeométrica e o pêndulo simples." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306997.
Full textAbstract:
Orientador: Edmundo Capelas de OliveiraDissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica
Made available in DSpace on 2018-08-17T14:35:07Z (GMT). No. of bitstreams: 1 Rosa_EsterCristinaFontesdeAquino_M.pdf: 847998 bytes, checksum: d177526572b19cc1fdd5eeccdf511380 (MD5) Previous issue date: 2011
Resumo: Este trabalho tem por objetivo modelar e resolver, matematicamente, um problema físico conhecido como pêndulo simples. Discutimos, como caso particular, as chamadas oscilações de pequena amplitude, isto é, uma aproximação que nos leva a mostrar que o período de oscilação é proporcional à raiz quadrada do quociente entre o comprimento do pêndulo e a aceleração da gravidade. Como vários outros problemas oriundos da Física, o pêndulo simples é representado através de equações diferenciais parciais. Assim, na busca de sua solução, aplicamos a metodologia de separação de variáveis que nos leva a um conjunto de equações ordinárias passíveis de simples integração. Escolhendo um sistema de coordenadas adequado, é conveniente usar o método de Hamilton-Jacobi, discutindo, antes, o problema do oscilador harmónico, apresentando, em seguida, o problema do pêndulo simples e impondo condições a fim de mostrar que as equações diferenciais associadas a esses dois sistemas são iguais, ou seja, suas soluções são equivalentes. Para tanto, estudamos o método de separação de variáveis associado às equações diferenciais parciais, lineares e de segunda ordem, com coeficientes constantes e três variáveis independentes, bem como a respectiva classificação quanto ao tipo. Posteriormente, estudamos as equações hipergeométricas, cujas soluções, as funções hipergeométricas. podem ser encontradas pelo método de Frobenius. Apresentamos o método de Hamilton-Jacobi, já mencionado, para o enfren-tamento do problema apresentado. Fizemos no capítulo final um apêndice sobre a função gama por sua presente importância no trato de funções hipergeométricas, em especial a integral elíptica completa de primeiro tipo que compõe a solução exata do período do pêndulo simples
Abstract: This work aims to present and solve, mathematically, the physics problem that is called simple pendulum. We reasoned, as an specific case, the so called low amplitude oscillation, that is, a convenient approximation that make us show that the period of oscillation is proportional to the quotient square root between the pendulum length and the gravity acceleration. Like several other problems arising from the physics, we are going to broach it through partial differential equations. Thus, in the search of its solution, we made use of the variable separation methodology that leads us to a body of ordinary equations susceptible of simple integration. Choosing an appropriate coordinate system, it is convenient to use the method Hamilton-Jacobi, arguing, first, the problem of the harmonic oscillator, with, then the problem of sf simple pendulum and imposing conditions to show that the differential equations associated with these two systems are equal, that is, their solutions are equivalent. With the purpose of reaching the objectives, we studied the variable separation method associated with partial differential equations, linear and of second order, with constant coefficient and three independent variables, as well as the respective classification about the type. Afterwards, we studied the hypergeometrical equations whose solutions, the hypergeometrical functions, are found by the Frobenius method. Introducing the Hamilton-Jacobi method, already mentioned, for addressing the problem presented. We made an appendix in the final chapter on the gamma function by its present importance in dealing with hypergeometric functions, in particular the elliptic integral of first kind consists of the exact period of sf simple pendulum
Mestrado
Fisica-Matematica
Mestre em Matemática
2
Gaertner, Nathaniel Allen. "Special Cases of Density Theorems in Algebraic Number Theory." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/33153.
Full textAbstract:
This paper discusses the concepts in algebraic and analytic number theory used in the proofs of Dirichlet's and Cheboterev's density theorems. It presents special cases of results due to the latter theorem for which greatly simplified proofs exist.Master of Science
3
Lagro, Matthew Patrick. "A Perron-Frobenius Type of Theorem for Quantum Operations." Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/339694.
Full textAbstract:
MathematicsPh.D.
Quantum random walks are a generalization of classical Markovian random walks to a quantum mechanical or quantum computing setting. Quantum walks have promising applications but are complicated by quantum decoherence. We prove that the long-time limiting behavior of the class of quantum operations which are the convex combination of norm one operators is governed by the eigenvectors with norm one eigenvalues which are shared by the operators. This class includes all operations formed by a coherent operation with positive probability of orthogonal measurement at each step. We also prove that any operation that has range contained in a low enough dimension subspace of the space of density operators has limiting behavior isomorphic to an associated Markov chain. A particular class of such operations are coherent operations followed by an orthogonal measurement. Applications of the convergence theorems to quantum walks are given.
Temple University--Theses
4
Slegers, Wouter. "Spectral Theory for Perron-Frobenius operators." Thesis, Uppsala universitet, Tillämpad matematik och statistik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-396647.
Full text
5
Cuszynski-Kruk, Mikolaj. "On Frobenius Theorem and Classication of 2-Dimensional Real Division Algebras." Thesis, Uppsala universitet, Algebra och geometri, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414086.
Full text
6
Stigner, Carl. "Hopf and Frobenius algebras in conformal field theory." Doctoral thesis, Karlstads universitet, Avdelningen för fysik och elektroteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-14456.
Full textAbstract:
There are several reasons to be interested in conformal field theories in two dimensions. Apart from arising in various physical applications, ranging from statistical mechanics to string theory, conformal field theory is a class of quantum field theories that is interesting on its own. First of all there is a large amount of symmetries. In addition, many of the interesting theories satisfy a finiteness condition, that together with the symmetries allows for a fully non-perturbative treatment, and even for a complete solution in a mathematically rigorous manner. One of the crucial tools which make such a treatment possible is provided by category theory. This thesis contains results relevant for two different classes of conformal field theory. We partly treat rational conformal field theory, but also derive results that aim at a better understanding of logarithmic conformal field theory. For rational conformal field theory, we generalize the proof that the construction of correlators, via three-dimensional topological field theory, satisfies the consistency conditions to oriented world sheets with defect lines. We also derive a classifying algebra for defects. This is a semisimple commutative associative algebra over the complex numbers whose one-dimensional representations are in bijection with the topological defect lines of the theory. Then we relax the semisimplicity condition of rational conformal field theory and consider a larger class of categories, containing non-semisimple ones, that is relevant for logarithmic conformal field theory. We obtain, for any finite-dimensional factorizable ribbon Hopf algebra H, a family of symmetric commutative Frobenius algebras in the category of bimodules over H. For any such Frobenius algebra, which can be constructed as a coend, we associate to any Riemann surface a morphism in the bimodule category. We prove that this morphism is invariant under a projective action of the mapping class group ofthe Riemann surface. This suggests to regard these morphisms as candidates for correlators of bulk fields of a full conformal field theories whose chiral data are described by the category of left-modules over H.
7
Pressland, Matthew. "Frobenius categorification of cluster algebras." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678852.
Full textAbstract:
Cluster categories, introduced by Buan–Marsh–Reineke–Reiten–Todorov and later generalised by Amiot, are certain 2-Calabi–Yau triangulated categories that model the combinatorics of cluster algebras without frozen variables. When frozen variables do occur, it is natural to try to model the cluster combinatorics via a Frobenius category, with the indecomposable projective-injective objects corresponding to these special variables. Amiot–Iyama–Reiten show how Frobenius categories admitting (d-1)-cluster-tilting objects arise naturally from the data of a Noetherian bimodule d-Calabi–Yau algebra A and an idempotent e of A such that A/< e > is finite dimensional. In this work, we observe that this phenomenon still occurs under the weaker assumption that A and A^op are internally d-Calabi–Yau with respect to e; this new definition allows the d-Calabi–Yau property to fail in a way controlled by e. Under either set of assumptions, the algebra B=eAe is Iwanaga–Gorenstein, and eA is a cluster-tilting object in the Frobenius category GP(B) of Gorenstein projective B-modules. Geiß–Leclerc–Schröer define a class of cluster algebras that are, by construction, modelled by certain Frobenius subcategories Sub(Q_J) of module categories over preprojective algebras. Buan–Iyama–Reiten–Smith prove that the endomorphism algebra of a cluster-tilting object in one of these categories is a frozen Jacobian algebra. Following Keller–Reiten, we observe that such algebras are internally 3-Calabi–Yau with respect to the idempotent corresponding to the frozen vertices, thus obtaining a large class of examples of such algebras. Geiß–Leclerc–Schröer also attach, via an algebraic homogenization procedure, a second cluster algebra to each category Sub(Q_J), by adding more frozen variables. We describe how to compute the quiver of a seed in this cluster algebra via approximation theory in the category Sub(Q_J); our alternative construction has the advantage that arrows between the frozen vertices appear naturally. We write down a potential on this enlarged quiver, and conjecture that the resulting frozen Jacobian algebra A and its opposite are internally 3-Calabi–Yau. If true, the algebra may be realised as the endomorphism algebra of a cluster-tilting object in a Frobenius category GP(B) as above. We further conjecture that GP(B) is stably 2-Calabi–Yau, in which case it would provide a categorification of this second cluster algebra.
8
McSween, Alexandra. "Affine Oriented Frobenius Brauer Categories and General Linear Lie Superalgebras." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42342.
Full textAbstract:
To any Frobenius superalgebra A we associate an oriented Frobenius Brauer category and an affine oriented Frobenius Brauer categeory. We define natural actions of these categories on categories of supermodules for general linear Lie superalgebras gl_m|n(A) with entries in A. These actions generalize those on module categories for general linear Lie superalgebras and queer Lie superalgebras, which correspond to the cases where A is the ground field and the two-dimensional Clifford superalgebra, respectively. We include background on monoidal supercategories and Frobenius superalgebras and discuss some possible further directions.
9
Drescher, Chelsea. "Invariants of Polynomials Modulo Frobenius Powers." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703327/.
Full textAbstract:
Rational Catalan combinatorics connects various Catalan numbers to the representation theory of rational Cherednik algebras for Coxeter and complex reflection groups. Lewis, Reiner, and Stanton seek a theory of rational Catalan combinatorics for the general linear group over a finite field. The finite general linear group is a modular reflection group that behaves like a finite Coxeter group. They conjecture a Hilbert series for a space of invariants under the action of this group using (q,t)-binomial coefficients. They consider the finite general linear group acting on the quotient of a polynomial ring by iterated powers of the irrelevant ideal under the Frobenius map. Often conjectures about reflection groups are solved by considering the local case of a group fixing one hyperplane and then extending via the theory of hyperplane arrangements to the full group. The Lewis, Reiner and Stanton conjecture had not previously been formulated for groups fixing a hyperplane. We formulate and prove their conjecture in this local case.
10
Hochart, Antoine. "Nonlinear Perron-Frobenius theory and mean-payoff zero-sum stochastic games." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX079/document.
Full textAbstract:
Les jeux stochastiques à somme nulle possèdent une structure récursive qui s'exprime dans leur opérateur de programmation dynamique, appelé opérateur de Shapley. Ce dernier permet d'étudier le comportement asymptotique de la moyenne des paiements par unité de temps. En particulier, le paiement moyen existe et ne dépend pas de l'état initial si l'équation ergodique - une équation non-linéaire aux valeurs propres faisant intervenir l'opérateur de Shapley - admet une solution. Comprendre sous quelles conditions cette équation admet une solution est un problème central de la théorie de Perron-Frobenius non-linéaire, et constitue le principal thème d'étude de cette thèse. Diverses classes connues d'opérateur de Shapley peuvent être caractérisées par des propriétés basées entièrement sur la relation d'ordre ou la structure métrique de l'espace. Nous étendons tout d'abord cette caractérisation aux opérateurs de Shapley "sans paiements", qui proviennent de jeux sans paiements instantanés. Pour cela, nous établissons une expression sous forme minimax des fonctions homogènes de degré un et non-expansives par rapport à une norme faible de Minkowski. Nous nous intéressons ensuite au problème de savoir si l'équation ergodique a une solution pour toute perturbation additive des paiements, problème qui étend la notion d'ergodicité des chaînes de Markov. Quand les paiements sont bornés, cette propriété d'"ergodicité" est caractérisée par l'unicité, à une constante additive près, du point fixe d'un opérateur de Shapley sans paiement. Nous donnons une solution combinatoire s'exprimant au moyen d'hypergraphes à ce problème, ainsi qu'à des problèmes voisins d'existence de points fixes. Puis, nous en déduisons des résultats de complexité. En utilisant la théorie des opérateurs accrétifs, nous généralisons ensuite la condition d'hypergraphes à tous types d'opérateurs de Shapley, y compris ceux provenant de jeux dont les paiements ne sont pas bornés. Dans un troisième temps, nous considérons le problème de l'unicité, à une constante additive près, du vecteur propre. Nous montrons d'abord que l'unicité a lieu pour une perturbation générique des paiements. Puis, dans le cadre des jeux à information parfaite avec un nombre fini d'actions, nous précisons la nature géométrique de l'ensemble des perturbations où se produit l'unicité. Nous en déduisons un schéma de perturbations qui permet de résoudre les instances dégénérées pour l'itération sur les politiquesZero-sum stochastic games have a recursive structure encompassed in their dynamic programming operator, so-called Shapley operator. The latter is a useful tool to study the asymptotic behavior of the average payoff per time unit. Particularly, the mean payoff exists and is independent of the initial state as soon as the ergodic equation - a nonlinear eigenvalue equation involving the Shapley operator - has a solution. The solvability of the latter equation in finite dimension is a central question in nonlinear Perron-Frobenius theory, and the main focus of the present thesis. Several known classes of Shapley operators can be characterized by properties based entirely on the order structure or the metric structure of the space. We first extend this characterization to "payment-free" Shapley operators, that is, operators arising from games without stage payments. This is derived from a general minimax formula for functions homogeneous of degree one and nonexpansive with respect to a given weak Minkowski norm. Next, we address the problem of the solvability of the ergodic equation for all additive perturbations of the payment function. This problem extends the notion of ergodicity for finite Markov chains. With bounded payment function, this "ergodicity" property is characterized by the uniqueness, up to the addition by a constant, of the fixed point of a payment-free Shapley operator. We give a combinatorial solution in terms of hypergraphs to this problem, as well as other related problems of fixed-point existence, and we infer complexity results. Then, we use the theory of accretive operators to generalize the hypergraph condition to all Shapley operators, including ones for which the payment function is not bounded. Finally, we consider the problem of uniqueness, up to the addition by a constant, of the nonlinear eigenvector. We first show that uniqueness holds for a generic additive perturbation of the payments. Then, in the framework of perfect information and finite action spaces, we provide an additional geometric description of the perturbations for which uniqueness occurs. As an application, we obtain a perturbation scheme allowing one to solve degenerate instances of stochastic games by policy iteration
11
Külshammer, Julian [Verfasser]. "Representation type and Auslander-Reiten theory of Frobenius-Lusztig kernels / Julian Külshammer." Kiel : Universitätsbibliothek Kiel, 2012. http://d-nb.info/102256109X/34.
Full text
12
Clark, Eric Logan. "COMBINATORIAL ASPECTS OF EXCEDANCES AND THE FROBENIUS COMPLEX." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_diss/158.
Full textAbstract:
In this dissertation we study the excedance permutation statistic. We start by extending the classical excedance statistic of the symmetric group to the affine symmetric group eSn and determine the generating function of its distribution. The proof involves enumerating lattice points in a skew version of the root polytope of type A. Next we study the excedance set statistic on the symmetric group by defining a related algebra which we call the excedance algebra. A combinatorial interpretation of expansions from this algebra is provided. The second half of this dissertation deals with the topology of the Frobenius complex, that is the order complex of a poset whose definition was motivated by the classical Frobenius problem. We determine the homotopy type of the Frobenius complex in certain cases using discrete Morse theory. We end with an enumeration of Q-factorial posets. Open questions and directions for future research are located at the end of each chapter.
13
Gautier, Antoine [Verfasser], and Matthias [Akademischer Betreuer] Hein. "Perron-Frobenius theorem for multi-homogeneous mappings with applications to nonnegative tensors / Antoine Gautier ; Betreuer: Matthias Hein." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2019. http://d-nb.info/1201647207/34.
Full text
14
Gautier, Antoine Verfasser], and Matthias [Akademischer Betreuer] [Hein. "Perron-Frobenius theorem for multi-homogeneous mappings with applications to nonnegative tensors / Antoine Gautier ; Betreuer: Matthias Hein." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2019. http://d-nb.info/1201647207/34.
Full text
15
Barra, Aleams. "Equivalence Theorems and the Local-Global Property." UKnowledge, 2012. http://uknowledge.uky.edu/math_etds/5.
Full textAbstract:
In this thesis we revisit some classical results about the MacWilliams equivalence theorems for codes over fields and rings. These theorems deal with the question whether, for a given weight function, weight-preserving isomorphisms between codes can be described explicitly. We will show that a condition, which was already known to be sufficient for the MacWilliams equivalence theorem, is also necessary. Furthermore we will study a local-global property that naturally generalizes the MacWilliams equivalence theorems. Making use of F-partitions, we will prove that for various subgroups of the group of invertible matrices the local-global extension principle is valid.
16
Farris, Lindsey. "Normal p-Complement Theorems." Youngstown State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1525865906237554.
Full text
17
Qu, Zheng. "Nonlinear Perron-Frobenius theory and max-plus numerical methods for Hamilton-Jacobi equations." Palaiseau, Ecole polytechnique, 2013. http://pastel.archives-ouvertes.fr/docs/00/92/71/22/PDF/thesis.pdf.
Full textAbstract:
Une approche fondamentale pour la résolution de problémes de contrôle optimal est basée sur le principe de programmation dynamique. Ce principe conduit aux équations d'Hamilton-Jacobi, qui peuvent être résolues numériquement par des méthodes classiques comme la méthode des différences finies, les méthodes semi-lagrangiennes, ou les schémas antidiffusifs. À cause de la discrétisation de l'espace d'état, la dimension des problèmes de contrôle pouvant être abordés par ces méthodes classiques est souvent limitée à 3 ou 4. Ce phénomène est appellé malédiction de la dimension. Cette thèse porte sur les méthodes numériques max-plus en contôle optimal deterministe et ses analyses de convergence. Nous étudions et developpons des méthodes numériques destinées à attenuer la malédiction de la dimension, pour lesquelles nous obtenons des estimations théoriques de complexité. Les preuves reposent sur des résultats de théorie de Perron-Frobenius non linéaire. En particulier, nous étudions les propriétés de contraction des opérateurs monotones et non expansifs, pour différentes métriques de Finsler sur un cône (métrique de Thompson, métrique projective d'Hilbert). Nous donnons par ailleurs une généralisation du "coefficient d'ergodicité de Dobrushin" à des opérateurs de Markov sur un cône général. Nous appliquons ces résultats aux systèmes de consensus ainsi qu'aux équations de Riccati généralisées apparaissant en contrôle stochastiqueDynamic programming is one of the main approaches to solve optimal control problems. It reduces the latter problems to Hamilton-Jacobi partial differential equations (PDE). Several techniques have been proposed in the literature to solve these PDE. We mention, for example, finite difference schemes, the so-called discrete dynamic programming method or semi-Lagrangian method, or the antidiffusive schemes. All these methods are grid-based, i. E. , they require a discretization of the state space, and thus suffer from the so-called curse of dimensionality. The present thesis focuses on max-plus numerical solutions and convergence analysis for medium to high dimensional deterministic optimal control problems. We develop here max-plus based numerical algorithms for which we establish theoretical complexity estimates. The proof of these estimates is based on results of nonlinear Perron-Frobenius theory. In particular, we study the contraction properties of monotone or non-expansive nonlinear operators, with respect to several classical metrics on cones (Thompson's metric, Hilbert's projective metric), and obtain nonlinear or non-commutative generalizations of the "ergodicity coefficients" arising in the theory of Markov chains. These results have applications in consensus theory and also to the generalized Riccati equations arising in stochastic optimal control
18
Kartsaklis, Dimitrios. "Compositional distributional semantics with compact closed categories and Frobenius algebras." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:1f6647ef-4606-4b85-8f3b-c501818780f2.
Full textAbstract:
The provision of compositionality in distributional models of meaning, where a word is represented as a vector of co-occurrence counts with every other word in the vocabulary, offers a solution to the fact that no text corpus, regardless of its size, is capable of providing reliable co-occurrence statistics for anything but very short text constituents. The purpose of a compositional distributional model is to provide a function that composes the vectors for the words within a sentence, in order to create a vectorial representation that re ects its meaning. Using the abstract mathematical framework of category theory, Coecke, Sadrzadeh and Clark showed that this function can directly depend on the grammatical structure of the sentence, providing an elegant mathematical counterpart of the formal semantics view. The framework is general and compositional but stays abstract to a large extent. This thesis contributes to ongoing research related to the above categorical model in three ways: Firstly, I propose a concrete instantiation of the abstract framework based on Frobenius algebras (joint work with Sadrzadeh). The theory improves shortcomings of previous proposals, extends the coverage of the language, and is supported by experimental work that improves existing results. The proposed framework describes a new class of compositional models thatfind intuitive interpretations for a number of linguistic phenomena. Secondly, I propose and evaluate in practice a new compositional methodology which explicitly deals with the different levels of lexical ambiguity (joint work with Pulman). A concrete algorithm is presented, based on the separation of vector disambiguation from composition in an explicit prior step. Extensive experimental work shows that the proposed methodology indeed results in more accurate composite representations for the framework of Coecke et al. in particular and every other class of compositional models in general. As a last contribution, I formalize the explicit treatment of lexical ambiguity in the context of the categorical framework by resorting to categorical quantum mechanics (joint work with Coecke). In the proposed extension, the concept of a distributional vector is replaced with that of a density matrix, which compactly represents a probability distribution over the potential different meanings of the specific word. Composition takes the form of quantum measurements, leading to interesting analogies between quantum physics and linguistics.
19
Jacoby, Adam Michael. "ON REPRESENTATION THEORY OF FINITE-DIMENSIONAL HOPF ALGEBRAS." Diss., Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/433432.
Full textAbstract:
MathematicsPh.D.
Representation theory is a field of study within abstract algebra that originated around the turn of the 19th century in the work of Frobenius on representations of finite groups. More recently, Hopf algebras -- a class of algebras that includes group algebras, enveloping algebras of Lie algebras, and many other interesting algebras that are often referred to under the collective name of ``quantum groups'' -- have come to the fore. This dissertation will discuss generalizations of certain results from group representation theory to the setting of Hopf algebras. Specifically, our focus is on the following two areas: Frobenius divisibility and Kaplansky's sixth conjecture, and the adjoint representation and the Chevalley property.
Temple University--Theses
20
Francis, Amanda. "New Computational Techniques in FJRW Theory with Applications to Landau Ginzburg Mirror Symmetry." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3265.
Full textAbstract:
Mirror symmetry is a phenomenon from physics that has inspired a lot of interesting mathematics. In the Landau-Ginzburg setting, we have two constructions, the A and B models, which are created based on a choice of an affine singularity with a group of symmetries. Both models are vector spaces equipped with multiplication and a pairing (making them Frobenius algebras), and they are also Frobenius manifolds. We give a result relating stabilization of singularities in classical singularity to its counterpart in the Landau-Ginzburg setting. The A model comes from so-called FJRW theory and can be de fined up to a full cohomological field theory. The structure of this model is determined by a generating function which requires the calculation of certain numbers, which we call correlators. In some cases the their values can be computed using known techniques. Often, there is no known method for finding their values. We give new computational methods for computing concave correlators, including a formula for concave genus-zero, four-point correlators and show how to extend these results to find other correlator values. In many cases these new methods give enough information to compute the A model structure up to the level of Frobenius manifold. We give the FJRW Frobenius manifold structure for various choices of singularities and groups.
21
Usatine, Jeremy. "Arithmetical Graphs, Riemann-Roch Structure for Lattices, and the Frobenius Number Problem." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/hmc_theses/57.
Full textAbstract:
If R is a list of positive integers with greatest common denominator equal to 1, calculating the Frobenius number of R is in general NP-hard. Dino Lorenzini defines the arithmetical graph, which naturally arises in arithmetic geometry, and a notion of genus, the g-number, that in specific cases coincides with the Frobenius number of R. A result of Dino Lorenzini's gives a method for quickly calculating upper bounds for the g-number of arithmetical graphs. We discuss the arithmetic geometry related to arithmetical graphs and present an example of an arithmetical graph that arises in this context. We also discuss the construction for Lorenzini's Riemann-Roch structure and how it relates to the Riemann-Roch theorem for finite graphs shown by Matthew Baker and Serguei Norine.
We then focus on the connection between the Frobenius number and arithmetical graphs. Using the Laplacian of an arithmetical graph and a formulation of chip-firing on the vertices of an arithmetical graph, we show results that can be used to find arithmetical graphs whose g-numbers correspond to the Frobenius number of R. We describe how this can be used to quickly calculate upper bounds for the Frobenius number of R.
22
Cruz, Josà Tiago Nogueira. "AplicaÃÃes de cÃlculo diferencial exterior a teoria econÃmica." Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3546.
Full textAbstract:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoFundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico
O trabalho consiste em decompor uma forma diferencial, sob algumas condiÃÃes iniciais, para conseguirmos resolvermos problemas na economia.
O trabalho consiste em decompor uma forma diferencial, sob algumas condiÃÃes iniciais, para conseguirmos resolvermos problemas na economia.
23
Zanasi, Fabio. "Interacting Hopf Algebras- the Theory of Linear Systems." Thesis, Lyon, École normale supérieure, 2015. http://www.theses.fr/2015ENSL1020/document.
Full textAbstract:
Dans cette thèse, on présente la théorie algébrique IH par le biais de générateurs et d’équations.Le modèle libre de IH est la catégorie des sous-espaces linéaires sur un corps k. Les termes de IH sont des diagrammes de cordes, qui, selon le choix de k, peuvent exprimer différents types de réseaux et de formalismes graphiques, que l’on retrouve dans des domaines scientifiques divers, tels que les circuits quantiques, les circuits électriques et les réseaux de Petri. Les équations de IH sont obtenues via des lois distributives entre algèbres de Hopf – d’où le nom “Interacting Hopf algebras” (algèbres de Hopf interagissantes). La caractérisation via les sous-espaces permet de voir IH comme une syntaxe fondée sur les diagrammes de cordes pour l’algèbre linéaire: les applications linéaires, les espaces et leurs transformations ont chacun leur représentation fidèle dans le langage graphique. Cela aboutit à un point de vue alternatif, souvent fructueux, sur le domaine.On illustre cela en particulier en utilisant IH pour axiomatiser la sémantique formelle de circuits de calculs de signaux, pour lesquels on s’intéresse aux questions de la complète adéquation et de la réalisabilité. Notre analyse suggère un certain nombre d’enseignements au sujet du rôle de la causalité dans la sémantique des systèmes de calculWe present by generators and equations the algebraic theory IH whose free model is the category oflinear subspaces over a field k. Terms of IH are string diagrams which, for different choices of k, expressdifferent kinds of networks and graphical formalisms used by scientists in various fields, such as quantumcircuits, electrical circuits and Petri nets. The equations of IH arise by distributive laws between Hopfalgebras - from which the name interacting Hopf algebras. The characterisation in terms of subspacesallows to think of IH as a string diagrammatic syntax for linear algebra: linear maps, spaces and theirtransformations are all faithfully represented in the graphical language, resulting in an alternative, ofteninsightful perspective on the subject matter. As main application, we use IH to axiomatise a formalsemantics of signal processing circuits, for which we study full abstraction and realisability. Our analysissuggests a reflection about the role of causality in the semantics of computing devices
24
Webb, Rachel Megan. "The Frobenius Manifold Structure of the Landau-Ginzburg A-model for Sums of An and Dn Singularities." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3794.
Full textAbstract:
In this thesis we compute the Frobenius manifold of the Landau-Ginzburg A-model (FJRW theory) for certain polynomials. Specifically, our computations apply to polynomials that are sums of An and Dn singularities, paired with the corresponding maximal symmetry group. In particular this computation applies to several K3 surfaces. We compute the necessary correlators using reconstruction, the concavity axiom, and new techniques. We also compute the Frobenius manifold of the D3 singularity.
25
Kaufmann, Ralph M. "The geometry of moduli spaces of pointed curves, the tensor product in the theory of Frobenius manifolds and the explicit Künneth formula in quantum cohomology." Bonn : [s.n.], 1998. http://catalog.hathitrust.org/api/volumes/oclc/41464661.html.
Full text
26
Goodwin, Michelle. "Lattices and Their Application: A Senior Thesis." Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/cmc_theses/1317.
Full textAbstract:
Lattices are an easy and clean class of periodic arrangements that are not only discrete but associated with algebraic structures. We will specifically discuss applying lattices theory to computing the area of polygons in the plane and some optimization problems. This thesis will details information about Pick's Theorem and the higher-dimensional cases of Ehrhart Theory. Closely related to Pick's Theorem and Ehrhart Theory is the Frobenius Problem and Integer Knapsack Problem. Both of these problems have higher-dimension applications, where the difficulties are similar to those of Pick's Theorem and Ehrhart Theory. We will directly relate these problems to optimization problems and operations research.
27
Sandberg, Ryan Thor. "A Nonabelian Landau-Ginzburg B-Model Construction." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5833.
Full textAbstract:
The Landau-Ginzburg (LG) B-Model is a significant feature of singularity theory and mirror symmetry. Krawitz in 2010, guided by work of Kaufmann, provided an explicit construction for the LG B-model when using diagonal symmetries of a quasihomogeneous, nondegenerate polynomial. In this thesis we discuss aspects of how to generalize the LG B-model construction to allow for nondiagonal symmetries of a polynomial, and hence nonabelian symmetry groups. The construction is generalized to the level of graded vector space and the multiplication developed up to an unknown factor. We present complete examples of nonabelian LG B-models for the polynomials x^2y + y^3, x^3y + y^4, and x^3 + y^3 + z^3 + w^2.
28
Taylor, S. Richard. "Probabilistic Properties of Delay Differential Equations." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/1183.
Full textAbstract:
Systems whose time evolutions are entirely deterministic can nevertheless be studied probabilistically, i. e. in terms of the evolution of probability distributions rather than individual trajectories. This approach is central to the dynamics of ensembles (statistical mechanics) and systems with uncertainty in the initial conditions. It is also the basis of ergodic theory--the study of probabilistic invariants of dynamical systems--which provides one framework for understanding chaotic systems whose time evolutions are erratic and for practical purposes unpredictable. Delay differential equations (DDEs) are a particular class of deterministic systems, distinguished by an explicit dependence of the dynamics on past states. DDEs arise in diverse applications including mathematics, biology and economics. A probabilistic approach to DDEs is lacking. The main problems we consider in developing such an approach are (1) to characterize the evolution of probability distributions for DDEs, i. e. develop an analog of the Perron-Frobenius operator; (2) to characterize invariant probability distributions for DDEs; and (3) to develop a framework for the application of ergodic theory to delay equations, with a view to a probabilistic understanding of DDEs whose time evolutions are chaotic. We develop a variety of approaches to each of these problems, employing both analytical and numerical methods. In transient chaos, a system evolves erratically during a transient period that is followed by asymptotically regular behavior. Transient chaos in delay equations has not been reported or investigated before. We find numerical evidence of transient chaos (fractal basins of attraction and long chaotic transients) in some DDEs, including the Mackey-Glass equation. Transient chaos in DDEs can be analyzed numerically using a modification of the "stagger-and-step" algorithm applied to a discretized version of the DDE.
29
Johnson, Jared Drew. "An Algebra Isomorphism for the Landau-Ginzburg Mirror Symmetry Conjecture." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2793.
Full textAbstract:
Landau-Ginzburg mirror symmetry takes place in the context of affine singularities in CN. Given such a singularity defined by a quasihomogeneous polynomial W and an appropriate group of symmetries G, one can construct the FJRW theory (see [3]). This construction fills the role of the A-model in a mirror symmetry proposal of Berglund and H ubsch [1]. The conjecture is that the A-model of W and G should match the B-model of a dual singularity and dual group (which we denote by WT and GT). The B-model construction is based on the Milnor ring, or local algebra, of the singularity. We verify this conjecture for a wide class of singularities on the level of Frobenius algebras, generalizing work of Krawitz [10]. We also review the relevant parts of the constructions.
30
Euvrard, Charlotte. "Aspects explicites des fonctions L et applications." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA2074/document.
Full textAbstract:
Cette thèse s'intéresse aux fonctions L, à leurs aspects explicites et à leurs applications Dans le premier chapitre, nous donnons une définition précise de ce que nous appelons une fonction L ainsi que leurs principales propriétés, notamment concernant les invariants appelés paramètres locaux. Ensuite, nous traitons le cas des fonctions L d'Artin. Pour celles-ci, nous avons créé un programme dans le logiciel PARI/GP donnant les coefficients et les invariants d'une fonction L d'Artin lorsque le corps de base est Q.Le deuxième chapitre explicite un théorème dû à Henryk Iwaniec et Emmanuel Kowalski permettant de différencier deux fonctions L générales en considérant leurs paramètres locaux pour tous les premiers jusqu'à une certaine borne théorique.Dans la suite, nous constaterons que distinguer la somme des paramètres locaux de fonctions L d'Artin revient à séparer les caractères associés par les automorphismes de Frobenius. Ce sera l'objet du troisième chapitre qui est à relier au théorème de Chebotarev. En appliquant notre résultat à des caractères conjugués du groupe alterné, on obtient une borne sur un nombre premier p donnant l'écriture de la factorisation modulo p d'un polynôme répondant à certains critères. Ce travail est à comparer avec un résultat de Joël Bellaïche (2013). Nous illustrons enfin numériquement nos résultats en étudiant l'évolution de la borne sur des polynômes de la forme X^n+uX+v avec n=5, 7 et 13This thesis focuses on L-functions, their explicit aspects and their applications.In the first chapter, we give a precise definition of L-functions and their main properties, especially about the invariants called local parameters. Then, we deal with Artin L-functions. For them, we have created a computer program in PARI/GP which gives the coefficients and the invariants for an Artin L-function above Q.In the second chapter, we make explicit a theorem of Henryk Iwaniec and Emmanuel Kowalski, which distinguishes between two L-functions by considering their local parameters for primes up to a theoretical bound.Actually, distinguishing between sums of local parameters of Artin L-functions is the same as separating the associated characters by the Frobenius automorphism. This is the subject of the third chapter, that can be related to Chebotarev Theorem. By applying the result to conjugate characters of the alternating group, we get a bound for a prime p giving the factorization modulo $p$ of a certain polynomial. This work has to be compared with a result from Joël Bellaïche (2013).Finally, we numerically illustrate our results by studying the evolution of the bound on polynomials X^n+uX+v, for n=5, 7 and 13
31
Pllaha, Tefjol. "Equivalence of Classical and Quantum Codes." UKnowledge, 2019. https://uknowledge.uky.edu/math_etds/59.
Full textAbstract:
In classical and quantum information theory there are different types of error-correcting codes being used. We study the equivalence of codes via a classification of their isometries. The isometries of various codes over Frobenius alphabets endowed with various weights typically have a rich and predictable structure. On the other hand, when the alphabet is not Frobenius the isometry group behaves unpredictably. We use character theory to develop a duality theory of partitions over Frobenius bimodules, which is then used to study the equivalence of codes. We also consider instances of codes over non-Frobenius alphabets and establish their isometry groups. Secondly, we focus on quantum stabilizer codes over local Frobenius rings. We estimate their minimum distance and conjecture that they do not underperform quantum stabilizer codes over fields. We introduce symplectic isometries. Isometry groups of binary quantum stabilizer codes are established and then applied to the LU-LC conjecture.
32
Vasireddy, Jhansi Lakshmi. "Applications of Linear Algebra to Information Retrieval." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/math_theses/71.
Full textAbstract:
Some of the theory of nonnegative matrices is first presented. The Perron-Frobenius theorem is highlighted. Some of the important linear algebraic methods of information retrieval are surveyed. Latent Semantic Indexing (LSI), which uses the singular value de-composition is discussed. The Hyper-Text Induced Topic Search (HITS) algorithm is next considered; here the power method for finding dominant eigenvectors is employed. Through the use of a theorem by Sinkohrn and Knopp, a modified HITS method is developed. Lastly, the PageRank algorithm is discussed. Numerical examples and MATLAB programs are also provided.
33
Novakovic, Novak. "Sémantique algébrique des ressources pour la logique classique." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL075N/document.
Full textAbstract:
Le thème général de cette thèse est l’exploitation de l’interaction entre la sémantique dénotationnelle et la syntaxe. Des sémantiques satisfaisantes ont été découvertes pour les preuves en logique intuitionniste et linéaire, mais dans le cas de la logique classique, la solution du problème est connue pour être particulièrement difficile. Ce travail commence par l’étude d’une interprétation concrète des preuves classiques dans la catégorie des ensembles ordonnés et bimodules, qui mène à l’extraction d’invariants significatifs. Suit une généralisation de cette sémantique concrète, soit l’interprétation des preuves classiques dans une catégorie compacte fermée où chaque objet est doté d’une structure d’algèbre de Frobenius. Ceci nous mène à une définition de réseaux de démonstrations pour la logique classique. Le concept de correction, l’élimination des coupures et le problème de la “full completeness” sont abordés au moyen d’un enrichissement naturel dans les ordres sur la catégorie de Frobenius, produisant une catégorie pour l'élimination des coupures et un concept de ressources pour la logique classique. Revenant sur notre première sémantique concrète, nous montrons que nous avons une représentation fidèle de la catégorie de Frobenius dans la catégorie des ensembles ordonnés et bimodulesThe general theme of this thesis is the exploitation of the fruitful interaction between denotational semantics and syntax. Satisfying semantics have been discovered for proofs in intuitionistic and certain linear logics, but for the classical case, solving the problem is notoriously difficult.This work begins with investigations of concrete interpretations of classical proofs in the category of posets and bimodules, resulting in the definition of meaningful invariants of proofs. Then, generalizing this concrete semantics, classical proofs are interpreted in a free symmetric compact closed category where each object is endowed with the structure of a Frobenius algebra. The generalization paves a way for a theory of proof nets for classical proofs. Correctness, cut elimination and the issue of full completeness are addressed through natural order enrichments defined on the Frobenius category, yielding a category with cut elimination and a concept of resources in classical logic. Revisiting our initial concrete semantics, we show we have a faithful representation of the Frobenius category in the category of posets and bimodules
34
Kallus, Paul Peter [Verfasser], Etienne [Akademischer Betreuer] Emmich, Karl-Heinz [Akademischer Betreuer] Förster, Jussi [Gutachter] Berndt, and Bela [Gutachter] Nagy. "Semi-monic operator functions : Perron-Frobenius theory, factorization in ordered Banach algebras and degree-reductions / Paul Peter Kallus ; Gutachter: Jussi Berndt, Bela Nagy ; Etienne Emmich, Karl-Heinz Förster." Berlin : Technische Universität Berlin, 2016. http://d-nb.info/1156013046/34.
Full text
35
Nyobe, Likeng Samuel Aristide. "Heisenberg Categorification and Wreath Deligne Category." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41167.
Full textAbstract:
We define a faithful linear monoidal functor from the partition category, and hence from Deligne's category Rep(S_t), to the additive Karoubi envelope of the Heisenberg category. We show that the induced map on Grothendieck rings is injective and corresponds to the Kronecker coproduct on symmetric functions.
We then generalize the above results to any group G, the case where G is the trivial group corresponding to the case mentioned above. Thus, to every group G we associate a linear monoidal category Par(G) that we call a group partition category. We give explicit bases for the morphism spaces and also an efficient presentation of the category in terms of generators and relations. We then define an embedding of Par(G) into the group Heisenberg category associated to G. This embedding intertwines the natural actions of both categories on modules for wreath products of G. Finally, we prove that the additive Karoubi envelope of Par(G) is equivalent to a wreath product interpolating category introduced by Knop, thereby giving a simple concrete description of that category.
36
Li, Zimu. "Fast Matrix Multiplication by Group Algebras." Digital WPI, 2018. https://digitalcommons.wpi.edu/etd-theses/131.
Full textAbstract:
Based on Cohn and Umans’ group-theoretic method, we embed matrix multiplication into several group algebras, including those of cyclic groups, dihedral groups, special linear groups and Frobenius groups. We prove that SL2(Fp) and PSL2(Fp) can realize the matrix tensor ⟨p, p, p⟩, i.e. it is possible to encode p × p matrix multiplication in the group algebra of such a group. We also find the lower bound for the order of an abelian group realizing ⟨n, n, n⟩ is n3. For Frobenius groups of the form Cq Cp, where p and q are primes, we find that the smallest admissible value of q must be in the range p4/3 ≤ q ≤ p2 − 2p + 3. We also develop an algorithm to find the smallest q for a given prime p.
37
Fagioli, Marta. "Statistica degli eventi rari nei sistemi dinamici." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/6942/.
Full textAbstract:
La teoria dei sistemi dinamici studia l'evoluzione nel tempo dei sistemi fisici e di altra natura. Nonostante la difficoltà di assegnare con esattezza una condizione iniziale (fatto che determina un non-controllo della dinamica del sistema), gli strumenti della teoria ergodica e dello studio dell'evoluzione delle densità di probabilità iniziali dei punti del sistema (operatore di Perron-Frobenius), ci permettono di calcolare la probabilità che un certo evento E (che noi definiamo come evento raro) accada, in particolare la probabilità che il primo tempo in cui E si verifica sia n. Abbiamo studiato i casi in cui l'evento E sia definito da una successione di variabili aleatorie (prima nel caso i.i.d, poi nel caso di catene di Markov) e da una piccola regione dello spazio delle fasi da cui i punti del sistema possono fuoriuscire (cioè un buco). Dagli studi matematici sui sistemi aperti condotti da Keller e Liverani, si ricava una formula esplicita del tasso di fuga nella taglia del buco. Abbiamo quindi applicato questo metodo al caso in cui l'evento E sia definito dai punti dello spazio in cui certe osservabili assumono valore maggiore o uguale a un dato numero reale a, per ricavare l'andamento asintotico in n della probabilità che E non si sia verificato al tempo n, al primo ordine, per a che tende all'infinito.
38
Brillon, Laura. "Matrices de Cartan, bases distinguées et systèmes de Toda." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30077/document.
Full textAbstract:
Dans cette thèse, nous nous intéressons à plusieurs aspects des systèmes de racines des algèbres de Lie simples. Dans un premier temps, nous étudions les coordonnées des vecteurs propres des matrices de Cartan. Nous commençons par généraliser les travaux de physiciens qui ont montré que les masses des particules dans la théorie des champs de Toda affine sont égales aux coordonnées du vecteur propre de Perron -- Frobenius de la matrice de Cartan. Puis nous adoptons une approche différente, puisque nous utilisons des résultats de la théorie des singularités pour calculer les coordonnées des vecteurs propres de certains systèmes de racines. Dans un deuxième temps, en s'inspirant des idées de Givental, nous introduisons les matrices de Cartan q-déformées et étudions leur spectre et leurs vecteurs propres. Puis, nous proposons une q-déformation des équations de Toda et construisons des 1-solitons solutions en adaptant la méthode de Hirota, d'après les travaux de Hollowood. Enfin, notre intérêt se porte sur un ensemble de transformations agissant sur l'ensemble des bases ordonnées de racines comme le groupe de tresses. En particulier, nous étudions les bases distinguées, qui forment l'une des orbites de cette action, et des matrices que nous leur associonsIn this thesis, our goal is to study various aspects of root systems of simple Lie algebras. In the first part, we study the coordinates of the eigenvectors of the Cartan matrices. We start by generalizing the work of physicists who showed that the particle masses of the affine Toda field theory are equal to the coordinates of the Perron -- Frobenius eigenvector of the Cartan matrix. Then, we adopt another approach. Namely, using the ideas coming from the singularity theory, we compute the coordinates of the eigenvectors of some root systems. In the second part, inspired by Givental's ideas, we introduce q-deformations of Cartan matrices and we study their spectrum and their eigenvectors. Then, we propose a q-deformation of Toda's equations et compute 1-solitons solutions, using the Hirota's method and Hollowood's work. Finally, our interest is focused on a set of transformations which induce an action of the braid group on the set of ordered root basis. In particular, we study an orbit for this action, the set of distinguished basis and some associated matrices
39
Lin, Lijing. "Roots of stochastic matrices and fractional matrix powers." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/roots-of-stochastic-matrices-and-fractional-matrix-powers(3f7dbb69-7c22-4fe9-9461-429c25c0db85).html.
Full textAbstract:
In Markov chain models in finance and healthcare a transition matrix over a certain time interval is needed but only a transition matrix over a longer time interval may be available. The problem arises of determining a stochastic $p$th root of astochastic matrix (the given transition matrix). By exploiting the theory of functions of matrices, we develop results on the existence and characterization of stochastic $p$th roots. Our contributions include characterization of when a real matrix hasa real $p$th root, a classification of $p$th roots of a possibly singular matrix,a sufficient condition for a $p$th root of a stochastic matrix to have unit row sums,and the identification of two classes of stochastic matrices that have stochastic $p$th roots for all $p$. We also delineate a wide variety of possible configurationsas regards existence, nature (primary or nonprimary), and number of stochastic roots,and develop a necessary condition for existence of a stochastic root in terms of the spectrum of the given matrix. On the computational side, we emphasize finding an approximate stochastic root: perturb the principal root $A^{1/p}$ or the principal logarithm $\log(A)$ to the nearest stochastic matrix or the nearest intensity matrix, respectively, if they are not valid ones;minimize the residual $\normF{X^p-A}$ over all stochastic matrices $X$ and also over stochastic matrices that are primary functions of $A$. For the first two nearness problems, the global minimizers are found in the Frobenius norm. For the last two nonlinear programming problems, we derive explicit formulae for the gradient and Hessian of the objective function $\normF{X^p-A}^2$ and investigate Newton's method, a spectral projected gradient method (SPGM) and the sequential quadratic programming method to solve the problem as well as various matrices to start the iteration. Numerical experiments show that SPGM starting with the perturbed $A^{1/p}$to minimize $\normF{X^p-A}$ over all stochastic matrices is method of choice.Finally, a new algorithm is developed for computing arbitrary real powers $A^\a$ of a matrix $A\in\mathbb{C}^{n\times n}$. The algorithm starts with a Schur decomposition,takes $k$ square roots of the triangular factor $T$, evaluates an $[m/m]$ Pad\'e approximant of $(1-x)^\a$ at $I - T^$, and squares the result $k$ times. The parameters $k$ and $m$ are chosen to minimize the cost subject to achieving double precision accuracy in the evaluation of the Pad\'e approximant, making use of a result that bounds the error in the matrix Pad\'e approximant by the error in the scalar Pad\'e approximant with argument the norm of the matrix. The Pad\'e approximant is evaluated from the continued fraction representation in bottom-up fashion, which is shown to be numerically stable. In the squaring phase the diagonal and first superdiagonal are computed from explicit formulae for $T^$, yielding increased accuracy. Since the basic algorithm is designed for $\a\in(-1,1)$, a criterion for reducing an arbitrary real $\a$ to this range is developed, making use of bounds for the condition number of the $A^\a$ problem. How best to compute $A^k$ for a negative integer $k$ is also investigated. In numerical experiments the new algorithm is found to be superior in accuracy and stability to several alternatives,including the use of an eigendecomposition, a method based on the Schur--Parlett\alg\ with our new algorithm applied to the diagonal blocks and approaches based on the formula $A^\a = \exp(\a\log(A))$.
40
Adje, Assalé. "Optimisation et jeux appliqués à l'analyse statique de programmes par interprétation abstraite." Phd thesis, Ecole Polytechnique X, 2011. http://pastel.archives-ouvertes.fr/pastel-00607076.
Full textAbstract:
L'interprétation abstraite est une méthode générale qui permet de déterminer de manière automatique des invariants de programmes. Cette méthode conduit à résoudre un problème de point fixe non linéaire de grande taille mais qui possède des propriétés de monotonie. Ainsi, déterminer des bornes sur les valeurs prises par une variable au cours de l'exécution d'un programme, est un problème de point fixe équivalent à un problème de jeu à deux joueurs, à somme nulle et avec options d'arrêt. Cette dernière observation explique la mise en oeuvre d'algorithmes d'itérations sur les politiques. Dans un premier temps, nous avons généralisé les domaines numériques polyédriques par un domaine numérique abstrait permettant de représenter des invariants non-linéaires. Nous avons défini une fonction sémantique abstraite sur ce domaine à partir d'une correspondance de Galois. Cependant, l'évaluation de celle-ci est aussi difficile qu'un problème d'optimisation globale non-convexe. Cela nous a amené à définir une fonction sémantique relâchée, construite à partir de la théorie de la dualité, qui sur-approxime de la fonction sémantique abstraite. La théorie de la dualité a également motivé une construction d'une itération sur les politiques dynamique pour calculer des invariants numériques. En pratique pour des programmes écrits en arithmétique affine, nous avons combiné la relaxation de Shor et l'information des fonctions de Lyapunov quadratique pour évaluer la fonction sémantique relâchée et ainsi générer des invariants numériques sous forme d'ellipsoïdes tronquées. Le deuxième travail concerne l'itération sur les politiques et le calcul du plus petit point fixe qui fournit l'invariant le plus précis. Nous avons raffiné l'itération sur les politiques afin de produire le plus petit point fixe dans le cas des jeux stochastiques. Ce raffinement repose sur des techniques de théorie de Perron-Frobenius non-linéaire. En effet, la fonction sémantique abstraite sur les intervalles peut être vue comme un opérateur de Shapley en information parfaite: elle est semidifférentiable. L'approche conjointe de la semidifférentielle et des rayons spectraux non linéaires nous a permis, dans le cas des contractions au sens large de caractériser le plus petit point fixe. Cette approche mène à un critère d'arrêt pour l'itération sur politique dans le cas des fonctions affines par morceaux contractantes au sens large. Quand le point fixe est non minimal, le problème consiste à exhiber un point fixe négatif non nul de la semidifférentielle. Ce vecteur conduit à une nouvelle politique qui fournit un point fixe strictement plus petit que le point fixe courant. Cette approche a été appliquée à quelques exemples de jeux stochastiques à paiements positifs et de vérification de programmes.
41
Merry, Alexander. "Reasoning with !-graphs." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:416c2e6d-2932-4220-8506-50e6b403b660.
Full textAbstract:
The aim of this thesis is to present an extension to the string graphs of Dixon, Duncan and Kissinger that allows the finite representation of certain infinite families of graphs and graph rewrite rules, and to demonstrate that a logic can be built on this to allow the formalisation of inductive proofs in the string diagrams of compact closed and traced symmetric monoidal categories. String diagrams provide an intuitive method for reasoning about monoidal categories. However, this does not negate the ability for those using them to make mistakes in proofs. To this end, there is a project (Quantomatic) to build a proof assistant for string diagrams, at least for those based on categories with a notion of trace. The development of string graphs has provided a combinatorial formalisation of string diagrams, laying the foundations for this project. The prevalence of commutative Frobenius algebras (CFAs) in quantum information theory, a major application area of these diagrams, has led to the use of variable-arity nodes as a shorthand for normalised networks of Frobenius algebra morphisms, so-called "spider notation". This notation greatly eases reasoning with CFAs, but string graphs are inadequate to properly encode this reasoning. This dissertation firstly extends string graphs to allow for variable-arity nodes to be represented at all, and then introduces !-box notation – and structures to encode it – to represent string graph equations containing repeated subgraphs, where the number of repetitions is abitrary. This can be used to represent, for example, the "spider law" of CFAs, allowing two spiders to be merged, as well as the much more complex generalised bialgebra law that can arise from two interacting CFAs. This work then demonstrates how we can reason directly about !-graphs, viewed as (typically infinite) families of string graphs. Of particular note is the presentation of a form of graph-based induction, allowing the formal encoding of proofs that previously could only be represented as a mix of string diagrams and explanatory text.
42
Contatto, Felipe. "Vortices, Painlevé integrability and projective geometry." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/275099.
Full textAbstract:
GaugThe first half of the thesis concerns Abelian vortices and Yang-Mills theory. It is proved that the 5 types of vortices recently proposed by Manton are actually symmetry reductions of (anti-)self-dual Yang-Mills equations with suitable gauge groups and symmetry groups acting as isometries in a 4-manifold. As a consequence, the twistor integrability results of such vortices can be derived. It is presented a natural definition of their kinetic energy and thus the metric of the moduli space was calculated by the Samols' localisation method. Then, a modified version of the Abelian–Higgs model is proposed in such a way that spontaneous symmetry breaking and the Bogomolny argument still hold. The Painlevé test, when applied to its soliton equations, reveals a complete list of its integrable cases. The corresponding solutions are given in terms of third Painlevé transcendents and can be interpreted as original vortices on surfaces with conical singularity. The last two chapters present the following results in projective differential geometry and Hamiltonians of hydrodynamic-type systems. It is shown that the projective structures defined by the Painlevé equations are not metrisable unless either the corresponding equations admit first integrals quadratic in first derivatives or they define projectively flat structures. The corresponding first integrals can be derived from Killing vectors associated to the metrics that solve the metrisability problem. Secondly, it is given a complete set of necessary and sufficient conditions for an arbitrary affine connection in 2D to admit, locally, 0, 1, 2 or 3 Killing forms. These conditions are tensorial and simpler than the ones in previous literature. By defining suitable affine connections, it is shown that the problem of existence of Killing forms is equivalent to the conditions of the existence of Hamiltonian structures for hydrodynamic-type systems of two components.
43
LIN, GUAN-YU, and 林冠宇. "Perron-Frobenius theorem and computation on multidimensional arrays." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/h4np99.
Full textAbstract:
碩士國立高雄大學
應用數學系碩博士班
106
The Perron-Frobenius theorem shows some important results on nonnegative irreducible matrices. This theorem has various applications and extensions. In this paper, we focus on the nonnegative irreducible matrices. After constructing a linear homotopy, we analyze the solution curve of the linear homotopy and prove that any nonnegative irreducible matrix has the positive eigenpair. This is the main result of the Perron-Frobenius theorem. The skill of the proof can be extended to prove the Perron-Frobenius theorem on tensors. Furthermore, the numerical results computed by the homotopy continuation method on nonnegative irreducible matrices and tensors are presented.
44
Perumal, Pragladan. "On the theory of the frobenius groups." Thesis, 2012. http://hdl.handle.net/10413/8853.
Full textAbstract:
The Frobenius group is an example of a split extension. In this dissertation we study and describe
the properties and structure of the group. We also describe the properties and structure of the
kernel and complement, two non-trivial subgroups of every Frobenius group. Examples of Frobenius
groups are included and we also describe the characters of the group. Finally we construct the
Frobenius group 292 : SL(2, 5) and then compute it's Fischer matrices and character table.Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
45
Sweet, Ross. "Equivariant unoriented topological field theories and G-extended Frobenius algebras." Thesis, 2013. https://hdl.handle.net/2144/14096.
Full textAbstract:
For a finite group G, we define G-equivariant unoriented topological quantum field theories and G-extended Frobenius algebras and prove an equivalence between the categories of these two structures. This gives an equivariant version of the equivalence of unoriented topological quantum field theories and extended Frobenius algebras due to Turaev-Turner. Further, for the weighted projective space P(1,n), we study the virtual orbifold K-theory and its related virtual Adams operations. By applying the non-Abelian localization of Edidin-Graham, we obtain natural generators for the virtual orbifold K-theory. We express the virtual line elements in terms of these generators, and use the virtual line elements to give a presentation of the virtual orbifold K-theory. For a particular crepant resolution of T*P(1,n), we show the usual K-theory of the resolution is isomorphic to a summand of the virtual orbifold K-theory. This gives an example of the K-theoretic version of the hyper-Kahler resolution conjecture and generalizes a result of Edidin-Jarvis-Kimura.
46
Fong, Yi June, and 方儀君. "Perron-Frobenius theorem for sampling operator and the error estimate for its spectral radius formula." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/59359648183021536303.
Full text
47
Pacheco, Rodríguez Edwin Fernando. "Grafos de Frobenius-Perron para categorías de fusión." Doctoral thesis, 2015. http://hdl.handle.net/11086/2805.
Full textAbstract:
Tesis (Doctor en Matemática)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía y Física, 2015.Sea C una categoría de fusión íntegra, en este trabajo se estudian algunos grafos, llamados el grafo primo y el grafo común divisor, relacionados con las dimensiones de Frobenius-Perron de los objetos simples de C. Estos grafos generalizan los grafos correspondientes asociados a los caracteres irreducibles y a los órdenes de las clases de conjugación en un grupo finito. Se describen los grafos en distintos casos específicos, entre otros, cuando C es una equivariantización bajo la acción de un grupo finito, una categoría 2-pasos nilpotente, y la categoría de representaciones de un doble de Drinfeld torcido de un grupo finito. Se demuestran generalizaciones al contexto de las categorías de fusión íntegras de resultados sobre el número de componentes conexas de los grafos correspondientes para grupos finitos. En particular, se prueba que si C es una categoría íntegra trenzada no degenerada, entonces el grafo primo de C tiene a lo sumo 3 componentes conexas, y tiene a lo sumo 2 componentes conexas si C es además resoluble. Como aplicación de los resultados principales, se demuestra un resultado de clasificación para categorías de fusión débilmente íntegras tales que las dimensiones de sus objetos simples son todas potencias de números primos.
Let C be an integral fusion category. In this work, we study some graphs, called the prime graph and the common divisor graph, related to the Frobenius-Perron dimensions of simple objects of C. This graphs extend the corresponding graphs associated to the irreducible character degrees and the conjugacy class sizes of a nite group. We describe these graphs in several cases, among others, when C is an equivariantization under the action of a nite group, a 2-step nilpotent fusion category, and the representation category of a twisted quantum double. We prove generalizations of known results on the number of connected components of the corresponding graphs for nite groups in the context of braided fusion categories. In particular, we show that if C is any integral nondegenerate braided fusion category, then the prime graph of C has at most 3 connected components, and it has at most 2 connected components if C is in addition solvable. As an application we prove a classi cation result for weakly integral braided fusion categories all of whose simple objects have prime power Frobenius- Perron dimension.
48
De, Gregorio Ignacio. "Deformations of functions and F-manifolds." Phd thesis, 2004. http://tel.archives-ouvertes.fr/tel-00145635.
Full textAbstract:
In this thesis we study deformations of functions on singular varieties with a view toward Frobenius manifolds. Chapter 2 is mainly introductory. We prove standard results in deformation theory for which we do not know a suitable reference. We also give a construction of the miniversal deformation of a function on a singular space that to the best of our knowledge does not appear in this form in literature.
In Chapter 3 we find a sufficient condition for the dimension of the base space of the miniversal deformation to be equal to the number of critical points into which the original singularity splits. We show that it holds for functions on smoothable and unobstructed curves and for function on isolated complete intersections singularities, unifying under the same argument previously known results.
In Chapter 4 we use the previous results to construct a multiplicative structure known as F -manifold on the base space of the miniversal deformation. We relate our construction to the theory of Frobenius manifolds by means of an example: mirrors of weighted projective lines.
The appendix is joint work with D. Mond. We study unfolding of composed functions under a suitable deformation category. It also yields an F-manifold structure on the base space, which we use to answer some questions raised by V. Goryunov and V. Zakalyukin on the discriminant on matrix deformations.
49
Lin, Ting-Yu, and 林庭瑀. "Perron-Frobenius Theory and Laplace Transformation for Estimating Parameters and High Order Moments in Multi-state Disease Process." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/wn2znd.
Full textAbstract:
碩士國立臺灣大學
流行病學與預防醫學研究所
105
Multistate statistical models are often used for dealing with the cardinal questions for infectious disease such as “whether and when the epidemic will occur after the introduction of infectives?” and also for chronic disease such as “how soon the disease will progress from early status to advanced one?”. Both questions are related to two main parameters, basic reproductive number for infectious disease and mean sojourn time for the progression of cancer. However, the derivation of transition kernels are often involved in non-negative matrix and also convolution form implicated in multistate disease process, which renders the statistical computation complex. Moreover, the derivation of moment, particularly higher order, is often hampered by intractable computation. These characteristics motivate me to propose Perron-Frobenius theory for dealing with non-negative matrix and apply Laplace transform to render statistical computation feasible. In spite of several statistical approaches proposed before, a systematic approach has been barely addressed. The aims of this thesis are there to (1) demonstrate how to apply Perron-Frobenius theory to multi-state model such as susceptible-infected-recovery model from which the first moment of basic reproductive number (R0) and its higher moments using Laplace transformation model can be derived; (2) to develop Laplace transformation of transition probabilities with convolution form for the widely used three-state and five-state stochastic process cancer ; (3) to estimate first moment and higher moments of the parameters implicated in three-state and five-state disease process with Laplace transformation;(4) to develop the estimation procedure for Laplace transformed likelihood with E-M algorithm for three-state and five-state model. Two applications were demonstrated, including the basic reproductive number used in infectious disease process (influenza epidemic in Taiwan and the epidemic of Ebola virus in different countries). The second is applied to three-state and five-state Markov model for the progression of breast cancer from free of breast cancer, preclinical detectable phase, and clinical phase with the consideration of lymph node invasion and tumour size as the advance and early state of preclinical detectable phase and clinical phase. My thesis compared the results of first moment of basic reproductive number in the outbreaks of influenza and Ebola using our proposed method in comparison with those based on the conventional methods and also demonstrated their second and high order moments, which cannot be reckoned by the conventional method. It illustrates how to estimate parameters based on Laplace transformed likelihood in conjunction with EM algorithm while applied to empirical data on breast cancer and colorectal cancer. The application of the proposed method is of assistance to elucidate the uncertainty of basic reproductive number and sojourns time in modelling infectious disease and cancer based on multistate disease process. The proposed Laplace transformed likelihood function to estimate parameters can solve the requirement of cumbersome computation and dispense with detailed time-stamped history data used for traditional likelihood function while the multistate disease process is implicated. The proposed approach can be applied to a number of multistate models pertaining to infectious and chronic disease for the derivation of high order moments, distribution function, and instantaneous change of transition of parameters.
50
Hsieh, Li-Yu Shelley. "Ergodic theory of mulitidimensional random dynamical systems." Thesis, 2008. http://hdl.handle.net/1828/1253.
Full textAbstract:
Given a random dynamical system T constructed from Jablonski transformations, consider its Perron-Frobenius operator P_T.
We prove a weak form of the Lasota-Yorke inequality for P_T and
thereby prove the existence of BV- invariant densities for T. Using the Spectral Decomposition Theorem we prove that the support of an invariant density is open a.e. and give conditions
such that the invariant density for T is unique. We study the asymptotic behavior
of the Markov operator P_T, especially when T has a unique absolutely continuous invariant measure (ACIM). Under the assumption of uniqueness, we obtain spectral stability in the sense of Keller. As an application, we can use Ulam's method to approximate the invariant density of P_T.