Relevant bibliographies by topics / Atomic universe

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Atomic universe'

Author: Grafiati
Published: 2 June 2025
Last updated: 5 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Atomic universe.'

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.

Journal articles on the topic "Atomic universe"

1

Gangadhara, Rao Irlapati. "A New Hypothetical Model of Cosmology." American Based Research Journal 4, no. 10 (2019): 01–09. https://doi.org/10.5281/zenodo.3441655.

Full text
Abstract:
<em>The cosmos is made up of universes in infinite number, having similar structure and properties, embedded one in each other and extended in ascending and descending order.To explain and justify this model, there are three universes so far known to us (a) Geo-Universe (b) Atomic-Universe (c) Energy-Universe. These three are having similar structure and properties, embedded one in each other and extended in ascending and descending order. Of these three, we known some extent about the internal structure and properties of the Geo-Universe but we do not known its external structure. We know some extent about the external structure and properties of the Energy-Universe but we do not know its internal structure. Between of these three universes, we came to know a large extent about the internal &amp; external structure and properties of the Atomic-Universe. Hence, I have taken the similarities of internal structure &amp; properties between the Geo-Universe &amp; Atomic-Universe to propose that all the universes in ascending and descending order of the creation are having similar internal structure and properties. The similarities of external structure &amp; properties between the Atomic Universe and Energy-Universe are taken to propose that all the universe in ascending and descending order of creation are having similar external structure and properties. And the manner in which of these three universes i.e., embedded one in each other, extended in ascending and descending order to propose that all the universes in ascending and descending order of the creation are embedded one in each other and extended in ascending and descending order.</em>
APA, Harvard, Vancouver, ISO, and other styles
2

Carlson, Shawn. "Modeling the Atomic Universe." Scientific American 281, no. 4 (1999): 118–19. http://dx.doi.org/10.1038/scientificamerican1099-118.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Ward, Jessie Davis. "A Study of Systemology and Astronomic Atomic Structures." JOURNAL OF ADVANCES IN PHYSICS 13, no. 1 (2017): 4507–21. http://dx.doi.org/10.24297/jap.v13i1.5583.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Slabin, Uladzimir. "SCIENTIFIC EPONYM IN EDUCATIONAL UNIVERSE." Journal of Baltic Science Education 16, no. 2 (2017): 144–47. http://dx.doi.org/10.33225/jbse/17.16.144.

Full text
Abstract:
Strictly speaking, knowledge for every object in educational Universe is limited by ignorance or, in other words, these two components co-exist. However, pedagogy primarily deals with knowledge, its acquisition and retention. It ignores the ignorance, leaving it as a subject for a more generic science of psychology. Similarly, atomic nuclei in real Universe are a subject for a more generic science of physics, being only slightly studied in chemistry. To research on knowledge is by far easier than on ignorance, same as chemical research involving mere electron shells is easier than physical research targeting atomic nuclei.
APA, Harvard, Vancouver, ISO, and other styles
5

Taylor, Emory, and Rajan Iyer. "Antisymmetry and antimatter in the universe." Physics Essays 37, no. 2 (2024): 165–68. http://dx.doi.org/10.4006/0836-1398-37.2.165.

Full text
Abstract:
Discontinuum physics (DCP) provides the non-arbitrary requirement for excluding the antimatter solutions to Dirac’s equation, resulting in a matter‐antimatter asymmetry. A matter‐antimatter asymmetrical universe then results from coupling the matter‐antimatter asymmetry with (1) the prior DCP proposal that the universe came into existence from a quantum fluctuation of a type of vacuum state with a zero net total energy, (2) allowing this quantum fluctuation to constitute a discontinuity containing the non-arbitrary requirement, with this occurring similar to how DCP showed the atomic absorption and emission process (AE-process) of Bohr’s atomic model constitutes a discontinuity, and (3) allowing this discontinuity to be conserved when the universe comes into existence, with this occurring similar to how DCP showed the AE-process discontinuity of Bohr’s atomic model is conserved as the emitted electromagnetic radiation (i.e., photon) discontinuity, where (a) a photon spends a large amount of time in the nonzero state during which it can interact with another photon in a collision, becoming a matter‐antimatter pair, and (b) a photon spends a tiny amount of time in the zero state during which it cannot interact with any particles and allowing it to be capable of spontaneously become a matter particle.
APA, Harvard, Vancouver, ISO, and other styles
6

Flower, D. R. "Three-body recombination of hydrogen in the early Universe." Monthly Notices of the Royal Astronomical Society: Letters 523, no. 1 (2023): L1—L3. http://dx.doi.org/10.1093/mnrasl/slad047.

Full text
Abstract:
ABSTRACT It has been suggested recently that three-body recombination of two protons and an electron might be significant in the formation of atomic hydrogen in the early Universe. We demonstrate that this process is completely negligible in the primordial plasma and that the value of the redshift, at which the transition from ionized to atomic hydrogen occurs, is determined by an equilibrium between the rates of two-body radiative recombination of a proton and an electron and its inverse, namely photoionization of atomic hydrogen.
APA, Harvard, Vancouver, ISO, and other styles
7

Lepp, S., P. C. Stancil, and A. Dalgarno. "Atomic and molecular processes in the early Universe." Journal of Physics B: Atomic, Molecular and Optical Physics 35, no. 10 (2002): R57—R80. http://dx.doi.org/10.1088/0953-4075/35/10/201.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Chutjian, A., J. Simcic, S. M. Madzunkov, J. A. MacAskill, R. J. Mawhorter, and E. Tsikata. "Collision physics in the atomic and molecular universe." Journal of Physics: Conference Series 388, no. 1 (2012): 012042. http://dx.doi.org/10.1088/1742-6596/388/1/012042.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Hill, Ryley, Kiyoshi W. Masui, and Douglas Scott. "The Spectrum of the Universe." Applied Spectroscopy 72, no. 5 (2018): 663–88. http://dx.doi.org/10.1177/0003702818767133.

Full text
Abstract:
Cosmic background (CB) radiation, encompassing the sum of emission from all sources outside our own Milky Way galaxy across the entire electromagnetic spectrum, is a fundamental phenomenon in observational cosmology. Many experiments have been conceived to measure it (or its constituents) since the extragalactic Universe was first discovered; in addition to estimating the bulk (cosmic monopole) spectrum, directional variations have also been detected over a wide range of wavelengths. Here we gather the most recent of these measurements and discuss the current status of our understanding of the CB from radio to γ-ray energies. Using available data in the literature, we piece together the sky-averaged intensity spectrum and discuss the emission processes responsible for what is observed. We examine the effect of perturbations to the continuum spectrum from atomic and molecular line processes and comment on the detectability of these signals. We also discuss how one could, in principle, obtain a complete census of the CB by measuring the full spectrum of each spherical harmonic expansion coefficient. This set of spectra of multipole moments effectively encodes the entire statistical history of nuclear, atomic, and molecular processes in the Universe.
APA, Harvard, Vancouver, ISO, and other styles
10

Belmonte, Maria Teresa, Pratysuh R. Sen Sarma, and Santiago Mar. "Accurate new atomic data for Galactic Surveys." Proceedings of the International Astronomical Union 18, S371 (2022): 111–22. http://dx.doi.org/10.1017/s1743921323000273.

Full text
Abstract:
AbstractFor the last 20 years, Galactic Surveys have been revolutionizing our vision of the universe and broadening our understanding of the vastness of space that surrounds us. Galactic Surveys such as APOGEE, Gaia-ESO, GALAH, WEAVE and the currently-under-development 4MOST are teaching us a great deal about the chemical composition of stellar atmospheres, the formation and evolution of galaxies and how elements are synthesised in the universe. However, many questions remain unanswered and the current focus of ongoing and future surveys. Answering each of these questions requires the collection of data, normally as spectra, as most of the information we receive from the universe is electromagnetic radiation. Following the very expensive acquisition of astronomical spectra, another crucial task lies ahead: the analysis of these spectra to extract the priceless information they carry. High-quality atomic data of many neutral and ionised species is essential to conduct this analysis.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Atomic universe"

1

Morisset, Sabine. "Dynamique de la formation d'hydrogène moléculaire sur une poussière interstellaire." Phd thesis, Université Paris Sud - Paris XI, 2004. http://tel.archives-ouvertes.fr/tel-00008537.

Full text
Abstract:
Dans le milieu interstellaire (MIS), la formation de la molécule H_2 est catalysée par un grain de poussière : H+H+grain -> grain+ H_2 Deux mécanismes principaux correspondent à cette réaction: le mécanisme Eley-Rideal (ER) et le mécanisme Langmuir-Hinshelwood (LH). Les techniques de propagation de paquets d'ondes ont été utilisées pour étudier ces deux mécanismes aux faibles températures qui règnent dans le MIS. Pour rendre possible le calcul, il a fallu utiliser une grille en L et appliquer la technique de réduction de grille dite de « mapping » sur des grilles multidimensionnelles. Ceci a permis de couvrir une gamme d'énergie de collision comprise entre 0,4meV et 46meV pour le mécanisme ER, et entre 4meV et 50meV pour le mécanisme LH. Le mécanisme ER a été étudié en géométrie colinéaire sur une surface de graphite (0001), en autorisant le mouvement d'un atome de carbone du grain. Permettre cette relaxation du substrat favorise la réaction. Toutefois le mécanisme ER reste peu efficace dans les conditions de température régnant dans le MIS, du fait d'une petite bosse de potentiel en voie d'entrée. Le mécanisme LH a lui été étudié dans toute sa dimensionnalité sur une surface plane et rigide. Le résultat principal est que ce mécanisme est très efficace : dans des conditions caractéristiques du MIS, le temps mis par un atome H pour diffuser sur le grain, rencontrer un autre atome H, et désorber en H2 est inférieur au temps typique entre deux collisions H-grain. La réaction n'a aucun effet notable sur le rapport ortho- H_2 et para- H_2. En revanche, comme dans le mécanisme ER, elle conduit à une très forte excitation vibrationnelle de H_2.
APA, Harvard, Vancouver, ISO, and other styles
2

Langmack, Christian Bishop. "Universal Loss Processes in Bosonic Atoms with Positive Scattering Lengths." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385483878.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Bondu, François. "L'interféromètre Virgo :propriétés optiques, stabilisation en fréquence du laser." Habilitation à diriger des recherches, Université de Nice Sophia-Antipolis, 2008. http://tel.archives-ouvertes.fr/tel-00284986.

Full text
Abstract:
Un interféromètre à miroirs suspendus convertit les ondes gravitationnelles, perturbations de la géométrie de l'espace temps, en une variation de temps de vol d'aller-retour de photons entre deux masses inertielles au repos.<br />J'ai réalisé l'asservissement en fréquence du laser pour mesurer ces variations de temps de vol. La stabilité relative de fréquence en boucle du laser est de 1e-21 sur 100 ms ; je montre que le système obtenu respecte les spécifications. J'étudie dans le mémoire les propriétés d'un système où les boucles d'asservissements sont imbriquées.<br />Les cavités optiques résonnantes de l'interféromètre Virgo sont les éléments essentiels de la conversion d'une onde gravitationnelle. J'étudie l'ensemble des propriétés d'un oscillateur Fabry-Perot. Je montre comment elles peuvent être évaluées in situ à partir de mesures des fonctions de transfert utilisées pour leur verrouillage. Les cavités Fabry-Perot sont les oscillateurs de référence. Je fais un état des lieux de l'ensemble des perturbations susceptibles de perturber la stabilité de phase.
APA, Harvard, Vancouver, ISO, and other styles
4

Hebri, Salem. "Etudes de la pression de radiation dans les interféromètres utilisés pour la détection des ondes gravitationnelles." Phd thesis, Université de Nice Sophia-Antipolis, 2007. http://tel.archives-ouvertes.fr/tel-00175254.

Full text
Abstract:
Le détecteur Virgo est constitué d'un interféromètre de Michelson avec des cavités Fabry-Perot de 3 km de long dans les bras et utilise la technique du recyclage de la puissance. Il a pour but la détection directe des ondes gravitationnelles émises par des sources astrophysiques. Le système d'injection Virgo est constitué essentiellement d'une cavité triangulaire de 144 m appelée le mode cleaner, son rôle est de filtrer et de contrôler le faisceau d'entrée. Le miroir suspendu de la cavité est très léger (360 g) ce qui peut le rendre sensible à la pression des photons. J'ai développé des programmes de simulations pour une cavité triangulaire avec tous les contrôles identiques au mode cleaner de Virgo réel. Ces programmes peuvent être utilisés pour d'autres études. Une partie de la thèse est consacrée à<br />voir les effets de la pression de radiation sur le verrouillage longitudinal de la cavité, les effets du ressort optique angulaire etc. Dans une autre partie de la thèse j'observe les effets de la pression de radiation dans les bras de Virgo et l'existence des effets du ressort optique sur les degrés angulaires qui n'empêchent pas le bon fonctionnement de l'alignement. Enfin, je décris ma participation dans la recette de Virgo, qui consiste essentiellement à travailler sur les contrôles du système d'injection et leurs optimisations.
APA, Harvard, Vancouver, ISO, and other styles
5

Derouich, Moncef. "Étude des collisions dépolarisant les raies du "deuxième spectre'' du Soleil. Développement et exploitation d'une nouvelle méthode théorique." Phd thesis, Université Paris-Diderot - Paris VII, 2004. http://tel.archives-ouvertes.fr/tel-00331859.

Full text
Abstract:
Le spectre de polarisation linéaire observé au bord solaire (second spectre solaire) révèle une structure riche d'informations. L'interprétation quantitative de ce spectre de polarisation nécessite de prendre en compte les taux de dépolarisation par les collisions isotropes avec les atomes neutres d'hydrogène. Ces taux sont très mal connus à l'heure actuelle. Le développement d'une méthode collisionnelle, applicable au grand nombre d'atomes présents dans le second spectre solaire, et qui soit suffisamment précise et efficace, est indispensable pour combler ce vide. L'objectif de cette thèse est de répondre à ce besoin urgent. Dans cette thèse nous avons développé une nouvelle méthode semi-classique pour calculer les taux de dépolarisation et les taux de transfert de polarisation des raies spectrales des atomes et des ions par collisions avec les atomes neutres d'hydrogène (Derouich et al. 2003a; Derouich et al. 2003b; Derouich et al. 2004a; Derouich et al. 2004b). Notre méthode est une extension de celle développée et appliquée avec succès aux élargissement des raies par collisions avec les atomes neutres d'hydrogène, dans les années 90, par Anstee, Barklem et O'Mara. Un grand avantage de notre méthode est qu'elle n'est pas spécifique à un atome/ion perturbé donné; elle peut Ítre facilement appliquée à n'importe quel état de n'importe quel atome. Nous avons développé un code numérique pour calculer les taux de dépolarisation par notre nouvelle méthode, code inspiré de celui qui calcule l'élargissement des raies de Anstee, Barklem et O'Mara. Nous avons calculé les taux de dépolarisation pour les états $p$ $(l=1)$, $d$ $(l=2)$ et $f$ $(l$=3) des atomes neutres. Nous avons fourni des tableaux de données simples d'utilisation et permettant de déterminer les taux de dépolarisation pour de nombreux niveaux par interpolation ou par extrapolation. Nous avons étendu notre méthode et le code numérique qui lui est associé aux atomes une fois ionisés. Dans le but de valider notre théorie, nos résultats ont été comparés à des résultats de chimie quantique quand cela est possible. Les différences entre nos taux de dépolarisation et ceux obtenus par une approche de chimie quantique, dans les cas des atomes Na I, Mg I, et Ca I et l'ion Ca II, sont toujours inférieurs à 20 $\%$. De plus, nous nous sommes intéressé au cas important du SrI $5 p$ $^1P_{1}$: une erreur de 20-30 \% est attendue par rapport à des résultats basés sur un potentiel d'interaction hybride considéré comme étant le plus précis (section 6.5.1). Nos résultats ont été aussi comparé à ceux que nous avons obtenus en utilisant un potentiel de Van der Waals. Les taux de dépolarisation obtenus en utilisant ce potentiel sont largement sous-estimés. Nous avons ensuite interprété les observations des taux de polarisation linéaire de la raie \mbox{SrI 4607 Å}, obtenues avec THEMIS en Décembre 2002 par V. Bommier et G. Molodij, en terme de champ magnétique turbulent. Nous avons introduit nos taux de dépolarisation dans le code de transfert de rayonnement en présence de champ magnétique associé au formalisme développé par Landi Degl'Innocenti, Bommier et Sahal-Bréchot (1990). La détermination du champ magnétique dépend de faÁon très sensible de celle des vitesses microturbulente et macroturbulente. Nous avons déterminé Ces vitesses par superposition des profils des intensités théoriques, obtenus dans l'hypothèse d'une atmosphère non-magnétisée, à ceux observés. La différence entre la polarisation calculée pour une atmosphère non-magnétisée et la polarisation observée de la raie SrI 4607 Å $\;$ est cohérente avec la présence d'un champ magnétique moyen de 46 Gauss dans les région entre 200 et 300 km au-dessus du niveau correspondant à la profondeur optique $\tau_{5000}=1$. Enfin, nous avons montré qu'une erreur inférieure à 20 $\%$ sur les taux de dépolarisation correspond à une erreur inférieure à 10 $\%$ sur le champ magnétique turbulent qui en dérive. Cette erreur entre bien dans la barre d'erreur attendue sur la valeur du champ magnétique validant complètement notre méthode semi-classique de calcul des taux de dépolarisation pour contribuer à l'interprétation du second spectre du soleil.
APA, Harvard, Vancouver, ISO, and other styles
6

CARVALHO, RICARDO JOSE DE. "BRAZILIAN ATOMIC TIME SCALE: A PROPOSAL TO GENERALE A BRAZILIAN COORDINALED UNIVERSAL TIME." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2000. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8384@1.

Full text
Abstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>Neste trabalho nós procuramos uma solução para o problema: como construir uma escala de tempo atômico baseada em um pequeno grupo de relógios atômicos? Nós geramos uma escala de tempo atômico independente a partir de um conjunto de relógios atômicos, chamada ETAB1(onrj). Nós propomos que a ETAB1(ONRJ) seja usada como referência para a geração de um o novo Tempo Universal Coordenado Brasileiro, chamado de TUC(ONRJ) proposto. Nós mostramos que o TUC(ONRJ) proposto será mantido coordenado com o TUC(BIPM) dentro dos limites recomendados pelo Comité Consultatif pour la Définition de la Seconde, isto é, a diferença entre TUC e TUC(ONRJ) proposto, menor que mais ou menos 100ns. Para menter a Hora Legal Brasileira (TUC(ONRJ)) coordenada com a Hora Mundial (TUC(BIPM) é necessário realizar a rastreabilidade internacional da grandeza tempo. Um método é proposto para obtenção de uma estimativa diária da posição do TUC(ONRJ) utilizando o filtro de Kalman e um receptor GPS, com uma incerteza de mais ou menos 35ns. Uma comparação do desempenho entre as escalas de tempo TUC (ONRJ) proposto, TUC(NIST) e TUC(USNO) é apresentada<br>In the present work we look we look for a solution of the problem: how to construction na atomic time scale based in a smallgroup of atomic clocks. We generate an independent atomic time scale from an ensemble of atomic clocks, named ETAB 1 (ONRJ). We propose that ETAB 1(ONRJ) be used as a reference for the generation of a new Brazilian Coordinated Universal Time, named UTC (ONRJ)proposed. We show that the UTC (ONRJ)proposed will be maintained coordinated with UTC (BIPM) within the limitis recommended by the Comité consultatif pour la Définition de la Seconde, that is, the difference between UTC (BIMP) and UTC (ONRJ)proposed less than +/-100ns. To maintain the UTC (onrj) coordinated with UTC(BIPM) it is necessary to realize the international traceability of time quantity. A method is proposed for obtain ddaily estimates of UTC (ONRJ) - UTC(BIPM) using Kalman filter and GPS receiver with uncertainty of +/-35ns. A comparison of performance between the time scales UTC(ONRJ)proposed, UTC(NIST) and UTC(USNO) is presented.
APA, Harvard, Vancouver, ISO, and other styles
7

Troscompt, Nicolas. "Excitation collisionnelle du formaldéhyde interstellaire : théorie et observations." Phd thesis, Grenoble 1, 2009. http://www.theses.fr/2009GRE10213.

Full text
Abstract:
L'hydrogène moléculaire est la molécule la plus simple et la plus répandue dans l'Univers. Elle se présente sous deux formes, ortho- et para- H2correspondant aux différents alignements des spins de ses deux noyaux. Le rapport ortho/para de H2 est un paramètre essentiel pour comprendre les processus collisionnels inélastiques et réactifs dans les milieux astrophysiques moléculaires. Dans cette thèse, nous nous sommes intéressés à la détermination de ce rapport dans les nuages sombres, régions où H2 ne peut pas être observée directement. Dans ce but, nous avons utilisé la molécule de formaldéhyde (H2CO) dont l'excitation rotationnelle dans ces sources est dominée par les collisions avec H2. Une transition particulière a été choisie pour cette étude : la raie à 6 cm (4,8 GHz) de ortho-H2CO observée en absorption devant le fond diffus cosmologique. Si des études précédentes ont montré que cette absorption (antimaser) peut être expliquée par des effets collisionnels, aucune n'a étudié jusqu'à présent l'impact des formes ortho- et para-H2 sur l'absorption. Nous présentons, dans un premier temps, nos calculs haute-précision des taux d'excitation rotationnelle entre (ortho-,para-)H2CO et (ortho-,para-)H2. Nous montrons qu'il existe des différences significatives sur les taux de collisions selon le type de projectiles, et en particulier qu'il existe des différences entre ortho- et para-H2. Nous présentons ensuite l'utilisation de ces taux dans un modèle de transfert radiatif afin de reproduire les observations que nous avons menées au Green Bank Telescope sur la transition a 6 cm de ortho-H2CO en direction de 3 nuages sombres (B68, L134N et TMC-1). Nous montrons que les différences dans les taux de collisions calculés avec ortho- et para-H2 ont un impact significatif sur les simulations, nous permettant ainsi d'apporter des contraintes sur la valeur du rapport ortho/para de H2 dans ces milieux. Nous traitons en particulier l'exemple de B68, prototype de c\oe ur pre-stellaire<br>Molecular hydrogen is the simplest and most abundant molecule in the Universe. Owing to the possible different nuclear spin alignments, it presents two forms, ortho- and para-H2. The ortho-to-para ratio of H2 is a fundamental parameter to understand the (inelastic and reactive) collisional processes in molecular astrophysical media. In this thesis, we focus on the determination of the ortho-to-para ratio of H2 in dark clouds, where H2 cannot be directly observed. To this aim, we use the formaldehyde molecule (H2CO) whose rotational excitation in these sources is dominated by H2 collisions. A peculiar transition has been selected in our study: the 6-cm transition (4. 8 GHz) of ortho-H2CO observed in absorption against the cosmic microwave background. Previous studies have shown that collisional effects can explain this (antimaser) absorption but the impact of the ortho- and para- form of H2 on this absorption has been so far ignored. We first present high-precision computations of the (de)excitation rates of (ortho-, para-) H2CO by (ortho-, para-)H2. Significant differences are observed between ortho- and para-H2 rates. We then use these collisional rates in radiative transfer calculations in order to model 6-cm observations carried out with the Green Bank Telescope towards 3 different dark clouds (B68, L134N and TMC-1). We show that the differences in para and ortho-H2 collisional rates have a significant impact on the modeling, allowing us to put interesting constraints on the ortho-to-para ratio of H2 in dark clouds. We consider in detail the example of B68, prototype of pre-stellar cores
APA, Harvard, Vancouver, ISO, and other styles
8

Troscompt, Nicolas. "Excitation Collisionnelle du formaldéhyde interstellaire : Théorie et Observations." Phd thesis, Grenoble 1, 2009. http://tel.archives-ouvertes.fr/tel-00454581.

Full text
Abstract:
L'hydrogène moléculaire est la molécule la plus simple et la plus répandue dans l'Univers. Elle se présente sous deux formes, ortho- et para- H$_2$, correspondant aux différents alignements des spins de ses deux noyaux. Le rapport ortho/para de H$_2$ est un paramètre essentiel pour comprendre les processus collisionnels inélastiques et réactifs dans les milieux astrophysiques moléculaires. Dans cette thèse, nous nous sommes intéressés à la détermination de ce rapport dans les nuages sombres, régions où H$_2$ ne peut pas être observée directement. Dans ce but, nous avons utilisé la molécule de formaldéhyde (H$_2$CO) dont l'excitation rotationnelle dans ces sources est dominée par les collisions avec H$_2$. Une transition particulière a été choisie pour cette étude : la raie à 6 cm (4,8 GHz) de ortho-H$_2$CO observée en absorption devant le fond diffus cosmologique. Si des études précédentes ont montré que cette absorption (antimaser) peut être expliquée par des effets collisionnels, aucune n'a étudié jusqu'à présent l'impact des formes ortho- et para-H$_2$ sur l'absorption. Nous présentons, dans un premier temps, nos calculs haute-précision des taux d'excitation rotationnelle entre (ortho-,para-)H$_2$CO et (ortho-,para-)H$_2$. Nous montrons qu'il existe des différences significatives sur les taux de collisions selon le type de projectiles, et en particulier qu'il existe des différences entre ortho- et para-H$_2$. Nous présentons ensuite l'utilisation de ces taux dans un modèle de transfert radiatif afin de reproduire les observations que nous avons menées au Green Bank Telescope sur la transition a 6 cm de ortho-H$_2$CO en direction de 3 nuages sombres (B68, L134N et TMC-1). Nous montrons que les différences dans les taux de collisions calculés avec ortho- et para-H$_2$ ont un impact significatif sur les simulations, nous permettant ainsi d'apporter des contraintes sur la valeur du rapport ortho/para de H$_2$ dans ces milieux. Nous traitons en particulier l'exemple de B68, prototype de c\oe ur pre-stellaire.
APA, Harvard, Vancouver, ISO, and other styles
9

Shaeri, Maryam. "Super-inflation and perturbations in LQC, and scaling solutions in curved FRW universes." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10959/.

Full text
Abstract:
We investigate phenomenologies arising from two distinct sets of modifications introduced in Loop Quantum Cosmology (LQC), namely, the inverse volume and the holonomy corrections. We find scaling solutions in each setting and show they give rise to a period of super-inflation soon after the universe starts expanding. This type of inflation is explicitly shown to resolve the horizon problem with far fewer number of e-foldings compared to the standard inflationary model. Scalar field perturbations are obtained and we demonstrate their near scale invariance in agreement with the latest observations of the Cosmic Microwave Background (CMB). Consideration of tensor perturbations of the metric results in a large blue tilt for these fluctuations, which implies their amplitude will be suppressed by many orders of magnitude on the CMB compared to the predictions of the standard inflation. This LQC result is shared by the ekpyrotic model and the model of a universe sourced by a phantom field. Exploring a correspondence map at the cosmological background level between braneworld cosmologies and the inverse volume corrected LQC, we discover this map not to hold at the level of linear perturbations. This is found to be due to the different behaviour of the rate of the Hubble parameter in the two classes of models. A complete dynamical analysis of Friedmann-Robertson-Walker spacetimes we carry out results in the most general forms of late time attractor scaling solutions. Our examination includes expanding and contracting universes when a scalar field evolves along a positive or a negative potential. Known results in the literature are demonstrated to correspond to certain limits of our solutions.
APA, Harvard, Vancouver, ISO, and other styles
10

Huet, Landry. "Gravimétrie atomique sur puce et applications embarquées." Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00839785.

Full text
Abstract:
Dans la première partie de ce travail de thèse, on a étudié les causes d'anomalie de pesanteur, et plusieurs causes de bruit afin d'en tirer des conclusions sur la faisabilité de certaines applications industrielles qui impliqueraient notamment l'utilisation de gravimètres ou de gradiomètres embarqués. On envisage en particulier la possibilité de constituer un système de prévention des collisions pour la navigation sous-marine, d'utiliser un gravimètre pour détecter des cavités enfouies ou encore d'observer l'anomalie de pesanteur créée par le passage d'une vague de tsunami d'une part, et d'autre part on cherche autant que possible à quantifier en spectre de puissance les bruits classiques rencontrés en gravimétrie embarquée, ainsi que le bruit gravitationnel causé par les vagues. Dans la seconde partie, on décrit la réalisation d'un gravimètre à ondes de matière, qui aura la particularité d'utiliser des atomes piégés au voisinage d'une puce en carbure de silicium. Le développement des gravimètres à ondes de matière est en effet extrêmement prometteur en terme d'exactitude de mesure du champ de pesanteur, mais le principe de réalisation utilisé jusqu'à maintenant implique que la sensibilité limite de l'instrument est proportionnelle à sa taille. D'un autre côté depuis une dizaine d'années des puces constituées de fils conducteurs déposés sur un substrat en silicium ont été développées pour le piégeage et le refroidissement d'atomes. L'utilisation d'une puce à atomes devra permettre de démontrer la possibilité de mesurer le champ de pesanteur avec une sensibilité indépendante de la taille de l'instrument, ce qui mènera à la réalisation d'un gravimètre à atomes froids compact, donc potentiellement utilisable dans un véhicule. Le défi de ce démonstrateur est d'effectuer pour la première fois la séparation spatiale cohérente d'un nuage d'atomes sur une puce atomique, à des fins de métrologie
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Atomic universe"

1

Houston, Robert. The new universe. Blue Dolphin Pub., 1999.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Culeen, Aufoy B. K., 1946-, ed. In cage: Atomic electron cloud ; Welat : forming of the universe. Studio 1976, 1988.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Trainer, Thompson Jennifer, and Thompson Jennifer Trainer, eds. Beyond Einstein: The cosmic quest for the theory of the universe. Oxford University Press, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Trainer, Thompson Jennifer, ed. Beyond Einstein: The cosmic quest for the theory of the universe. Bantam Books, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Carus, Titus Lucretius. On the nature of the universe. Penguin Books, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Carus, Titus Lucretius. On the nature of the universe. Clarendon Press, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Susskind, Leonard. An introduction to black holes, information, and the string theory revolution: The holographic universe. World Scientific, 2005.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Carus, Titus Lucretius. On the nature of the universe. Oxford University Press, 2008.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Carus, Titus Lucretius. On the Nature of the Universe. Oxford University Press, 1999.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

E, Gava, ed. 1992 Summer School in High Energy Physics and Cosmology: Trieste, Italy, 15 June-31 July, 1992. River Edge, N.J., 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Atomic universe"

1

Goodsell, David S. "The Universe of Protein Folds." In Atomic Evidence. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32510-1_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kaastra, J. S. "Astrophysical Plasmas and Atomic Processes." In The Hot Universe. Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-4970-9_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Motz, Lloyd, and Jefferson Hane Weaver. "Atomic Structure and Stellar Spectra." In The Unfolding Universe. Springer US, 1989. http://dx.doi.org/10.1007/978-1-4899-5982-9_12.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Economou, Eleftherios N. "The Atomic Idea." In From Quarks to the Universe. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-20654-7_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Economou, Eleftherios N. "The Atomic Idea." In A Short Journey from Quarks to the Universe. Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-20089-2_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Raven, Will. "Introduction to Atoms and Light." In Atomic Physics for Everyone. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-69507-0_1.

Full text
Abstract:
AbstractIn this chapter, we explore the nature of light and atoms, focusing on their dual nature as both particles and waves. We examine why atoms have discrete energy levels and how only certain frequencies of light can excite electrons within these atoms. Through this exploration, we will understand the relationship between light’s frequency, wavelength, and photon energy. We also explore key concepts such as wave interference and the historical experiments that shaped our understanding of quantum mechanics. Most importantly, this chapter emphasizes the scientific method, encouraging continual questioning of ideas, understanding, theories, and results to uncover the fundamental nature of the universe.
APA, Harvard, Vancouver, ISO, and other styles
7

Takabe, Hideaki. "Atomic Process in Plasmas." In Springer Series in Plasma Science and Technology. Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-45473-8_5.

Full text
Abstract:
AbstractWhen a high-intensity laser is irradiated onto a solid gold (Z = 79), half of the electrons is partially ionized. The multi-electron structure of such ions is not obvious. Quantum mechanics of multi-electron systems and calculations of ionization statistics are required. In this chapter, the electrons in the ion are approximated to be bound in a spherically symmetric mean field, and the isolated atom is studied.The Hartree-Hock (HF) equation, which accurately describes atoms in many-electron systems, can be solved, but it is a daunting task. For this purpose, simple but error-prone approximations have been used, such as the HULLAC and OPAL codes, which use the para-potential method instead of a rigorous description of the HF. It is an intuitive and easy-to-understand approximation.Once the quantum state of the bound electrons can be calculated, the statistical distribution of ionization can be obtained by solving the Saha equation for thermal equilibrium. The threshold of ionization (continuum lowering) is determined. The calculation of such an ionic structure is presented. Due to the high temperature of the plasma, interaction with thermal radiation and free electrons cause excitation, ionization, and the reverse process. Calculations of these processes will be presented.Applications of the rate equations will be explained. In the recently introduced X-ray laser (XFEL) heating, free electrons are also non-equilibrium (non-Maxwellian). This chapter begins with a review of hydrogen and helium atoms, and then introduces the topics of atomic physics and processes from the laboratory to the universe.
APA, Harvard, Vancouver, ISO, and other styles
8

Silverman, Mark P. "Introduction: The Fire Within." In A Universe of Atoms, An Atom in the Universe. Springer New York, 2002. http://dx.doi.org/10.1007/978-0-387-22761-0_1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Silverman, Mark P. "A Universe of Atoms: Symmetry, Unity, Gravity, and the Problem of “Missing Mass”." In A Universe of Atoms, An Atom in the Universe. Springer New York, 2002. http://dx.doi.org/10.1007/978-0-387-22761-0_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Silverman, Mark P. "Science and Wonder." In A Universe of Atoms, An Atom in the Universe. Springer New York, 2002. http://dx.doi.org/10.1007/978-0-387-22761-0_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Atomic universe"

1

Sy, Jo Ann C., Blessie A. Basilia, Charito T. Aranilla, Carlo S. Emolaga, Vivian U. Lagura, and Marianito T. Margarito. "Comparison of the Mechanical, Thermal and Structural Properties of Gamma-Irradiated and Conventional SLA 3D Printed Methacrylate-Based Photo-Curable Resin for Biomedical Application." In 2024 8th International Conference on Materials Engineering and Nano Sciences & 2024 8th International Conference on Material Engineering and Manufacturing. Trans Tech Publications Ltd, 2024. http://dx.doi.org/10.4028/p-yi7lno.

Full text
Abstract:
This study aims to assess the morphological, thermal, chemical structure and mechanical properties of the gamma-irradiated and conventional (unirradiated) test specimens that were 3D printed using a methacrylate-based photo-curable resin and a stereolithography (SLA) 3D printer. The irradiated test specimens were exposed to 50 kGy gamma-ray dose. The morphological, thermal, chemical structure and mechanical properties of the irradiated and unirradiated test specimens were characterized using the Atomic Force Microscope (AFM), Differential scanning calorimeter (DSC), Thermogravimetric analyzer (TGA), Fourier Transform Infrared Spectrometer (FTIR) and Universal Testing Machine (UTM). Results showed that irradiated test specimens exhibited lower surface roughness compared to the unirradiated specimens. Gamma-irradiated specimens also showed improved tensile strength and modulus of elasticity by 12.2% and 12.4 %, respectively. FTIR, DSC and TGA results showed no significant changes in the chemical structure and thermal properties of the 3D printed methacrylate-based resin after subjecting to gamma irradiation.
APA, Harvard, Vancouver, ISO, and other styles
2

Radnaev, Alexander G., and team on behalf of Infleqtion’s Sqorpius. "Universal Gate-Based Quantum Computer With Individual Optical Addressing of Neutral Atom Qubits." In Frontiers in Optics. Optica Publishing Group, 2024. https://doi.org/10.1364/fio.2024.fw6c.4.

Full text
Abstract:
Infleqtion’s universal quantum computer uses individual optical addressing of neutral atom qubits, an architecture which promises fast gate operations on logical qubits. I will report on gate fidelities and other progress towards fault tolerance.
APA, Harvard, Vancouver, ISO, and other styles
3

Ostropolski-Nalewaja, Piotr, and Sebastian Rudolph. "The Sticky Path to Expressive Querying: Decidability of Navigational Queries under Existential Rules." In 21st International Conference on Principles of Knowledge Representation and Reasoning {KR-2023}. International Joint Conferences on Artificial Intelligence Organization, 2024. http://dx.doi.org/10.24963/kr.2024/54.

Full text
Abstract:
Extensive research in the field of ontology-based query answering has led to the identification of numerous fragments of existential rules (also known as tuple-generating dependencies) that exhibit decidable answering of atomic and conjunctive queries. Motivated by the increased theoretical and practical interest in navigational queries, this paper considers the question for which of these fragments decidability of querying extends to regular path queries (RPQs). In fact, decidability of RPQs has recently been shown to generally hold for the comprehensive family of all fragments that come with the guarantee of universal models being reasonably well-shaped (that is, being of finite cliquewidth). Yet, for the second major family of fragments, known as finite unification sets (short: fus), which are based on first-order-rewritability, corresponding results have been largely elusive so far. We complete the picture by showing that RPQ answering over arbitrary fus rulesets is undecidable. On the positive side, we establish that the problem is decidable for the prominent fus subclass of sticky rulesets, with the caveat that a very mild extension of the RPQ formalism turns the problem undecidable again.
APA, Harvard, Vancouver, ISO, and other styles
4

Ferland, Gary J., and Dmitri A. Verner. "Quasars, the early universe, and plasma simulations." In ATOMIC PROCESSES IN PLASMAS. ASCE, 1998. http://dx.doi.org/10.1063/1.56547.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lepp, Stephen. "Atomic and Molecular Processes in the Early Universe." In ATOMIC PHYSICS 19: XIX International Conference on Atomic Physics; ICAP 2004. AIP, 2005. http://dx.doi.org/10.1063/1.1928873.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Golubovsky, M., I. Shaikhislamov, and M. Rumenskikh. "Measurement of the metastable helium atomic rates important for astrophysical observations." In Modern astronomy: from the Early Universe to exoplanets and black holes. Special Astrophysical Observatory of the Russian Academy of Sciences, 2024. https://doi.org/10.26119/vak2024.132.

Full text
Abstract:
We present an experimental setup for measurement of the collisional rates relevant for the population of the triplet level of metastable helium. To estimate and verify the theoretical values, the absorption in helium plasma in the 1083 nm line will be measured. We are going to use plasma consisting of helium ions generated by $\theta$-pinch, filling in a 6 m$^3$ volume of a vacuum chamber at concentrations of $10^{12}$–$10^{13}$ cm$^{-3}$. Based on the expected parameters, the optical depth $\tau = 1$ is going to be achieved with a path length $L = 1$ km. To increase the effective path length in the plasma, an optical scheme based on a concave resonator is proposed.
APA, Harvard, Vancouver, ISO, and other styles
7

Korotin, S., and K. Kiselev. "Grid of NLTE corrections for sulfur lines in the atmospheres of A–K stars." In Modern astronomy: from the Early Universe to exoplanets and black holes. Special Astrophysical Observatory of the Russian Academy of Sciences, 2024. https://doi.org/10.26119/vak2024.067.

Full text
Abstract:
A correction grid is presented to take into account the influence of departures from local thermodynamic equilibrium on sulfur lines in the atmospheres of stars in the range of spectral classes from A to K. The correction grid was obtained using the atomic model of sulfur that takes into account the most modern atomic data on collision rates with electrons and hydrogen. The influence of NLTE effects on lines in both the optical and IR regions, including lines in the H-band, is considered. For some lines of neutral sulfur, which are practically not subject to NLTE effects, the wavelengths and oscillator strengths in the solar spectrum have been refined. The modified atomic model of sulfur, used to determine the sulfur abundance from the spectra of stars of different metallicities, has shown its reliability and adequacy. All sulfur lines are well described by similar element contents, regardless of their sensitivity to the influence of NLTE effects.
APA, Harvard, Vancouver, ISO, and other styles
8

Shepelin, A., M. Golubovsky, and I. Shaikhislamov. "Transit absorption in the oxygen lines for constraining the atmosphere temperature of hot exoplanets." In Modern astronomy: from the Early Universe to exoplanets and black holes. Special Astrophysical Observatory of the Russian Academy of Sciences, 2024. https://doi.org/10.26119/vak2024.139.

Full text
Abstract:
Atomic oxygen, due to its unique chemical properties, is widely used in astrophysics to study chemical composition, nucleosynthesis conditions, and the processes of formation and evolution. The recent detection of the O I 1304 Å and 7774 Å lines in the upper atmospheres of exoplanets using space and ground-based telescopes opens the possibility to evaluate its abundance in these objects and constrain important atmospheric parameters. However, the simple approximation of thermodynamic equilibrium is often inaccurate in describing the formation and absorption for many spectral lines in stars and hot exoplanets. The development of a kinetic model that takes into account detailed radiative and collisional processes in advanced atomic models is required to interpret the observations. In this work we for the first time analyze the advantages of transit absorption measurement of two oxygen lines simultaneously.
APA, Harvard, Vancouver, ISO, and other styles
9

A. Srećković, Vladimir, Sanja Tošić, Veljko Vujčić, and Darko Jevremović. "MOLECULAR SPECIES AND DATA RELEVANT FOR ASTROCHEMISTRY." In XIV Serbian-Bulgarian Astronomical Conference. Astronomical Observatory, 2024. http://dx.doi.org/10.69646/14sbac46a.

Full text
Abstract:
Atomic and molecular collisional and radiative processes are crucial for understanding the different environments within our universe (Albert et al. 2020). Data and databases on atomic and molecular processes have grown in importance for constructing models and simulations of complex physical/chemical processes, as well as interpreting observations and measurement findings in a variety of sectors (Srećković et al. 2020). The data can be used for a variety of applications, such as modeling non-local thermal equilibrium of the early universe's chemistry, modeling of the solar atmosphere, modeling of white dwarf atmospheres etc (Srećković et al. 2022). For conditions that exist in laboratory plasmas, planetary atmospheres, the ionosphere and other areas of science, it is primarily aimed at obtaining cross sections and rates coefficients for certain collisional and radiative processes. In this contribution, we present that type of data.Acknowledgments:This research was supported by the Science Fund of the Republic Serbia [Grant no. 3108/2021, NOVA2LIBS4fusion and Grant No. 7749560, EGWIn].References:[1] Albert, D., Antony, B. K., Ba, Y. A., Babikov, Y. L., Bollard, P., Boudon, V., ... &amp;amp; Zwölf, C. M. : 2020, Atoms, 8(4), 76.[2] Srećković V.A., Ignjatović L.M.,Dimitrijević M.S., Molecules, 2020, 26(1), 151.[3] Srećković V.A., Ignjatović L.M., Kolarski A., Mijić Z.R., Dimitrijević M.S., Vujčić V., Data, 2022, 7(9), 129.
APA, Harvard, Vancouver, ISO, and other styles
10

Qaid, Dalya Shaker. "Enhancement of Vapor Compression Refrigeration System by Adding Different Nano-Fluids: A Review." In The 2nd International Conference on The Future Sustainable Energy. Trans Tech Publications Ltd, 2024. http://dx.doi.org/10.4028/p-0fnjhm.

Full text
Abstract:
Scientists from a variety of fields have joined forces to study a world so small that it cannot be seen with the naked eye, not even under a light microscope. That is the domain of nanotechnology, the universe of atoms and nanostructures. Anything between 1 and 100 nm in size is generally considered to be within the purview of nanotechnology, despite the occasional disagreement among experts regarding precisely what is included in the nanoscale. That is not the atomic scale and the microscale is still larger. This paper will define nanotechnology and discuss its potential future applications. The application of nanoparticles in one of the mechanical engineering field's most significant uses will also be reviewed. The Vapor Compression Refrigeration System (VCRS) uses nanobased refrigerants to deliver a better, faster cooling process with less power consumption. resulting in the provision of a healthier environment and a more effective system.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Atomic universe"

1

Glasscott, Matthew. Classifying and benchmarking high-entropy alloys and associated materials for electrocatalysis : a brief review of best practices. Engineer Research and Development Center (U.S.), 2024. http://dx.doi.org/10.21079/11681/48082.

Full text
Abstract:
In light of the immense compositional diversity of high-entropy materials (HEMs) recently reported (e.g., high-entropy chalcogenides, perovskites, ceramics, etc.) and the relatively amorphous definition of High-Entropy, it is imperative that consistent material classification and benchmarking practices be employed to facilitate comparison between reported figures of merit. In this opinion, an updated form of the numerical high-entropy definition is reviewed, which renders a universal entropy metric applicable to high-entropy alloys and emerging HEMs alike. Analytical methods to verify the existence of a solid-solution microstructure, elucidate atomic valence states, and probe atomic disorder are discussed with literature examples to facilitate the physical classification of HEMs. Electrocatalytic benchmarking is discussed in the context of water-splitting reactions and best practices are reviewed for determining the electrocatalytically active surface area, reaction overpotential, and electrocatalyst stability.
APA, Harvard, Vancouver, ISO, and other styles
2

Timmermans, Eddy, and Mark Zammit. Molecular theory capability: LANL-PEM-Atomic implements universal descriptions of molecular photoionization. Office of Scientific and Technical Information (OSTI), 2025. https://doi.org/10.2172/2568545.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Küsters, Ralf, and Ralf Molitor. Computing Most Specific Concepts in Description Logics with Existential Restrictions. Aachen University of Technology, 2000. http://dx.doi.org/10.25368/2022.108.

Full text
Abstract:
Computing the most specific concept (msc) is an inference task that can be used to support the 'bottom-up' construction of knowledge bases for KR systems based on description logics. For description logics that allow for number restrictions or existential restrictions, the msc need not exist, though. Previous work on this problem has concentrated on description logics that allow for universal value restrictions and number restrictions, but not for existential restrictions. The main new contribution of this paper is the treatment of description logics with existential restrictions. More precisely, we show that, for the description logic ALE (which allows for conjunction, universal value restrictions, existential restrictions, negation of atomic concepts) the msc of an ABox-individual only exists in case of acyclic ABoxes. For cyclic ABoxes, we show how to compute an approximation of the msc. Our approach for computing the (approximation of the) msc is based on representing concept descriptions by certain trees and ABoxes by certain graphs, and then characterizing instance relationships by homomorphisms from trees into graphs. The msc/approximation operation then mainly corresponds to unraveling the graphs into trees and translating them back into concept descriptions.
APA, Harvard, Vancouver, ISO, and other styles
4

Gal'perin, Yu M., V. G. Karpov, and Володимир Миколайович Соловйов. Density of vibrational states in glasses. Springer, 1988. http://dx.doi.org/10.31812/0564/1005.

Full text
Abstract:
A theory of the vibrational spectra of glasses, based on allowance for the statistical fluctuations of the local elastic constants, is proposed. The existence is established of two characteristic energies h, and h, , dividing the spectrum into regions of qualitatively different behavior of the density of states n (h). At low frequencices w 4 w, the increase of the density of states is determined by the additive contributions of phonons and mutually noninteracting quasilocal vibrations in random soft atomic potentials in the glass. In the intermediate region w , 5 w 5 w, the quasilocal vibrations interact strongly with phonons, and this makes their contributions superadditive. For w &gt; w, the growth of n (h) slows down. As a result, n (h) increases at first more rapidly and then more slowly than the Debye density of states. An analytical expression for n (h) is obtained in the T-matrix formalism in the region w &lt;a,, including the region of strong scattering. A numerical calculation of n (h) is performed in the coherent-potential approximation. The theory predicts qualitatively universal behavior of n (h) in different glasses.
APA, Harvard, Vancouver, ISO, and other styles
5

GENERAL THEORY OF THE WHOLE PHYSICAL WORLD. SIB-Expertise, 2022. http://dx.doi.org/10.12731/er0599.29072022.

Full text
Abstract:
THE WORK CONSISTS IN COMBINING NEWTON'S CLASSICAL MECHANICS DESCRIBED BY EUCLIDIAN GEOMETRY, EINSTEIN'S GENERAL THEORY OF RELATIVITY, QUANTUM MECHANICS, THE THEORY OF SUPERSYMMETRY AND INFLATION THEORY ON THE BASIS OF THE BASIC LAW OF ECONOMIC HEALTH. THE PROPOSED THEORY, INCLUDING ALLOWS TO GIVE ANSWERS TO THE GLOBAL QUESTIONS OF TODAY'S COSMOLOGY AND ASTROPHYSICS: "WHAT WAS BEFORE THE BIG BANG?"; "WHAT IS DARK MATTER?"; "WHAT IS DARK ENERGY?"; “HOW TO UNDERSTAND PARALLEL WORLDS AND MULTI UNIVERSE''. THE WORK WILL SHOW A STRICT CORRELATION OF ALL INTERACTIONS (GRAVITATIONAL, ELECTROMAGNETIC, WEAK AND STRONG) BETWEEN PARTICLES OF MATTER, BOTH ON THE SCALE OF THE GALACTIC SYSTEM AND AT THE LEVEL OF NUCLEI OF ATOMS AND UNSTABLE OUTSIDE ATOMIC NUCLEI OF SUBATOMIC NUCLEI. THESE INTERACTIONS FORMED THE OBSERVABLE PICTURE OF THE WORLD.
APA, Harvard, Vancouver, ISO, and other styles
6

GENERAL THEORY OF THE WHOLE PHYSICAL WORLD. SIB-Expertise, 2022. http://dx.doi.org/10.12731/er0599.10082022.

Full text
Abstract:
THE WORK CONSISTS IN COMBINING NEWTON'S CLASSICAL MECHANICS DESCRIBED BY EUCLIDIAN GEOMETRY, EINSTEIN'S GENERAL THEORY OF RELATIVITY, QUANTUM MECHANICS, THE THEORY OF SUPERSYMMETRY AND INFLATION THEORY ON THE BASIS OF THE BASIC LAW OF ECONOMIC HEALTH. THE PROPOSED THEORY, INCLUDING ALLOWS TO GIVE ANSWERS TO THE GLOBAL QUESTIONS OF TODAY'S COSMOLOGY AND ASTROPHYSICS: "WHAT WAS BEFORE THE BIG BANG?"; "WHAT IS DARK MATTER?"; "WHAT IS DARK ENERGY?"; “HOW TO UNDERSTAND PARALLEL WORLDS AND MULTI UNIVERSE''. THE WORK WILL SHOW A STRICT CORRELATION OF ALL INTERACTIONS (GRAVITATIONAL, ELECTROMAGNETIC, WEAK AND STRONG) BETWEEN PARTICLES OF MATTER, BOTH ON THE SCALE OF THE GALACTIC SYSTEM AND AT THE LEVEL OF NUCLEI OF ATOMS AND UNSTABLE OUTSIDE ATOMIC NUCLEI OF SUBATOMIC NUCLEI. THESE INTERACTIONS FORMED THE OBSERVABLE PICTURE OF THE WORLD.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Atomic universe' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography