Articoli di riviste: "DARK ENERGY PHENOMENA"

1

Debnath, Subhra, e Abhik Kumar Sanyal. "Can particle-creation phenomena replace dark energy?" Classical and Quantum Gravity 28, n. 14 (7 giugno 2011): 145015. http://dx.doi.org/10.1088/0264-9381/28/14/145015.

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2

Capolupo, Antonio. "Quantum Vacuum, Dark Matter, Dark Energy, and Spontaneous Supersymmetry Breaking". Advances in High Energy Physics 2018 (10 aprile 2018): 1–7. http://dx.doi.org/10.1155/2018/9840351.

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We study the behavior of the vacuum condensates characterizing many physical phenomena. We show that condensates due to thermal states, to fields in curved space, and to neutrino mixing, may represent new components of the dark matter, whereas the condensate due to axion-photon mixing can contribute to the dark energy. Moreover, by considering a supersymmetric framework, we show that the nonzero energy of vacuum condensates may induce a spontaneous supersymmetry breaking.

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Capolupo, Antonio. "Dark Matter and Dark Energy Induced by Condensates". Advances in High Energy Physics 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/8089142.

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It is shown that the vacuum condensate induced by many phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states of fields in curved space and of mixed particles have been analyzed. It is shown that the thermal states with the cosmic microwave radiation temperature and the Unruh and the Hawking radiations give negligible contributions to the critical energy density of the universe, while the thermal vacuum of the intercluster medium could contribute to the dark matter, together with the vacuum energy of fields in curved space-time and of mixed neutrinos. Moreover, a component of the dark energy can be represented by the vacuum of axion-like particles mixed with photons and superpartners of neutrinos. The formal analogy among the systems characterized by the condensates can open new scenarios in the possibility of detecting the dark components of the universe in table top experiments.

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4

BREVIK, I., A. V. TIMOSHKIN e Y. RABOCHAYA. "LITTLE RIP AND PSEUDO RIP PHENOMENA FROM COUPLED DARK ENERGY". Modern Physics Letters A 28, n. 37 (20 novembre 2013): 1350172. http://dx.doi.org/10.1142/s0217732313501721.

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We consider Little Rip (LR) and Pseudo Rip (PR) cosmological models with two interacting ideal fluids, corresponding to dark energy and dark matter. The interaction between the dark energy and the dark matter fluid components is described in terms of the parameters in the equations of state for the LR and PR universes. In contrast to a model containing only a pure dark energy, the presence of the interaction term between the fluid components in the gravitational equations leads to a modification of the equation of state parameters. The properties of the early universe in this formalism are pointed out.

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5

Marongwe, Stuart. "The Nexus graviton: A quantum of Dark Energy and Dark Matter". International Journal of Geometric Methods in Modern Physics 11, n. 06 (luglio 2014): 1450059. http://dx.doi.org/10.1142/s0219887814500595.

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In a recently published paper called Nexus: A quantum theory of space-time, gravity and the quantum vacuum by the above author, a plausible self-consistent quantum theory of space-time, gravity and the quantum vacuum is provided. In this current paper the author focuses primarily on the graviton as described in Nexus as a solution to the enigmatic phenomena of Dark Energy and Dark Matter as well as includes corrections to the first paper.

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SAPONE, DOMENICO. "DARK ENERGY IN PRACTICE". International Journal of Modern Physics A 25, n. 29 (20 novembre 2010): 5253–331. http://dx.doi.org/10.1142/s0217751x10050743.

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In this paper we review a part of the approaches that have been considered to explain the extraordinary discovery of the late time acceleration of the Universe. We discuss the arguments that have led physicists and astronomers to accept dark energy as the current preferable candidate to explain the acceleration. We highlight the problems and the attempts to overcome the difficulties related to such a component. We also consider alternative theories capable of explaining the acceleration of the Universe, such as modification of gravity. We compare the two approaches and point out the observational consequences, reaching the sad but foresightful conclusion that we will not be able to distinguish between a Universe filled by dark energy or a Universe where gravity is different from General Relativity. We review the present observations and discuss the future experiments that will help us to learn more about our Universe. This is not intended to be a complete list of all the dark energy models but this paper should be seen as a review on the phenomena responsible for the acceleration. Moreover, in a landscape of hardly compelling theories, it is an important task to build simple measurable parameters useful for future experiments that will help us to understand more about the evolution of the Universe.

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ZHAO, HONGSHENG. "CONSTRAINING TEVES GRAVITY AS EFFECTIVE DARK MATTER AND DARK ENERGY". International Journal of Modern Physics D 16, n. 12a (dicembre 2007): 2055–63. http://dx.doi.org/10.1142/s0218271807011759.

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The phenomena customarily described with the standard ΛCDM model are broadly reproduced by an extremely simple model in TeVeS, Bekenstein's1 modification of general relativity motivated by galaxy phenomenology. Our model can account for the acceleration of the Universe seen at SNeIa distances without a cosmological constant, and the accelerations seen in rotation curves of nearby spiral galaxies and gravitational lensing of high-redshift elliptical galaxies without cold dark matter. The model is consistent with BBN and the neutrino mass between 0.05 eV to 2 eV. The TeVeS scalar field is shown to play the effective dual roles of dark matter and dark energy, with the amplitudes of the effects controlled by a μ function of the scalar field, called the μ essence here. We also discuss outliers to the theory's predictions on multiimaged galaxy lenses and outliers on the subgalaxy scale.

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Stuckey, W. M., Timothy McDevitt, A. K. Sten e Michael Silberstein. "End of a dark age?" International Journal of Modern Physics D 25, n. 12 (ottobre 2016): 1644004. http://dx.doi.org/10.1142/s0218271816440041.

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We argue that dark matter (DM)and dark energy phenomena associated with galactic rotation curves (RC’s), X-ray cluster mass profiles, and type Ia supernova data can be accounted for via small corrections to idealized general relativistic spacetime geometries due to disordered locality. Accordingly, we fit the HI nearby galaxy survey (THINGS) RC data rivaling modified Newtonian dynamics, Roentgen Satellite/Advanced Satellite for Cosmology and Astrophysics (ROSAT/ASCA) X-ray cluster mass profile data rivaling metric-skew-tensor gravity, and SCP Union2.1 SN Ia data rivaling [Formula: see text]CDM without nonbaryonic DM or a cosmological constant. In the case of DM, we geometrically modify proper mass interior to the Schwarzschild solution. In the case of dark energy, we modify proper distance in Einstein–de Sitter cosmology. Therefore, the phenomena of DM and dark energy may be chimeras created by an errant belief that spacetime is a differentiable manifold rather than a disordered graph.

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9

Alexandrovich Antonov, Alexander. "Principles and Structure of the Real Multiverse: Explanation of Dark Matter and Dark Energy Phenomena". American Journal of Modern Physics 4, n. 1 (2015): 1. http://dx.doi.org/10.11648/j.ajmp.20150401.11.

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10

Baker, Oliver, Andrei Afanasev, Theodota Lagouri, Jingjing Pan e Christian Weber. "Particle Physics of the Dark Sector". Symmetry 14, n. 11 (25 ottobre 2022): 2238. http://dx.doi.org/10.3390/sym14112238.

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The mystery associated with a proposed Dark Sector of phenomena that are separate from the standard model of particle physics is described. A Dark Sector may possess matter particles, force carriers which mediate their interactions, and new interactions and symmetries that are beyond the standard model of particle physics. Various approaches for Dark Sector searches are described, including those at the energy frontier at the Large Hadron Collider, in astrophysical interactions with both terrestrial experiments and those in space-born platforms. Searches using low energy photons from microwave energies in cryogenic environments to x-ray energies are also described. While there is no noncontroversial evidence for Dark Sector phenomena presently, new searches with more modern equipment and analysis methods are exploring regions of phase space that have not been available before now, indicating ongoing interest and excitement in this research.

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11

Torii, Kazufumi, Yasuo Fukui, Hidetoshi Sano, Junki Sato, Takeshi Okuda, Hiroaki Yamamoto, Akiko Kawamura, Norikazu Mizuno, Toshikazu Onishi e Hideo Ogawa. "Dark gas: a new possible link between low and high-energy phenomena". Proceedings of the International Astronomical Union 7, S284 (settembre 2011): 389–92. http://dx.doi.org/10.1017/s1743921312009477.

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AbstractGalactic-scale studies of γ-rays and sub-mm radiation suggest that a significant amount of neutral interstellar medium is not detectable either in CO or HI (Grenier et al. 2005; Ade et al. 2011). This component is called “dark gas”. Here we argue that cool and dense atomic gas without molecules is responsible for the dark gas. This interpretation is supported by a recent finding of cool HI gas corresponding to the TeV γ-ray shell in the SNR RX J1713.7-3946 (Fukui et al. 2011). Such HI gas is not recognized under a usual assumption of optically thin HI emission but is identified by a careful analysis considering optically thick HI. The typical column density of such HI gas is a few times 1021 cm−2 and is also identified as visual extinction.

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12

Mistele, Tobias. "Cherenkov radiation from stars constrains hybrid MOND dark matter models". Journal of Cosmology and Astroparticle Physics 2022, n. 11 (1 novembre 2022): 008. http://dx.doi.org/10.1088/1475-7516/2022/11/008.

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Abstract We propose a new method to constrain alternative models for dark matter with observations. Specifically, we consider hybrid models in which cold dark matter (CDM) phenomena on cosmological scales and Modified Newtonian Dynamics (MOND) phenomena on galactic scales share a common origin. Various such models were recently proposed. They typically contain a mode that is directly coupled to matter (for MOND) and has a non-relativistic sound speed (for CDM). This allows even non-relativistic objects like stars to lose energy through Cherenkov radiation. This is unusual. Most modified gravity models have a relativistic sound speed, so that only high-energy cosmic rays emit Cherenkov radiation. We discuss the consequences of this Cherenkov radiation from stars.

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13

Lagouri, Theodota. "Review on Higgs Hidden–Dark Sector Physics at High-Energy Colliders". Symmetry 14, n. 7 (22 giugno 2022): 1299. http://dx.doi.org/10.3390/sym14071299.

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The presence of a hidden or dark sector of phenomena that relates either weakly or in a particular way to Standard Model (SM) fields has theoretical as well as experimental support. Many extensions of SM use hidden or dark sector states to propose a specific candidate for dark matter (DM) in the universe or to explain astrophysical findings. If such a family of Beyond the Standard Model (BSM) particles and interactions exists, it is possible that they will be discovered experimentally at CERN’s Large Hadron Collider (LHC, √s≅14 TeV) and future High Energy Colliders. The primary emphasis is on a few examples of searches undertaken at the LHC that are relevant to Higgs Hidden–Dark Sector Physics. These studies’ existing constraints and prospects are also reported.

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14

Pretzl, Klaus. "Cryogenic detectors exploring new phenomena in physics and astrophysics". Europhysics News 52, n. 3 (2021): 18–21. http://dx.doi.org/10.1051/epn/2021303.

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The potential to measure small energy transfers with very high energy resolutions motivated the development of cryogenic detectors to search for dark matter in the universe, the neutrino mass, neutrinoless double beta decay, and new phenomena in astrophysics. Other fields like material and life sciences also benefited from these developments.

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15

Meierovich, Boris E. "Macroscopic Theory of Dark Sector". Journal of Gravity 2014 (1 ottobre 2014): 1–23. http://dx.doi.org/10.1155/2014/586958.

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A simple Lagrangian with squared covariant divergence of a vector field as a kinetic term turned out to be an adequate tool for macroscopic description of the dark sector. The zero-mass field acts as the dark energy. Its energy-momentum tensor is a simple additive to the cosmological constant. Massive fields describe two different forms of dark matter. The space-like massive vector field is attractive. It is responsible for the observed plateau in galaxy rotation curves. The time-like massive field displays repulsive elasticity. In balance with dark energy and ordinary matter it provides a four-parametric diversity of regular solutions of the Einstein equations describing different possible cosmological and oscillating nonsingular scenarios of evolution of the Universe. In particular, the singular big bang turns into a regular inflation-like transition from contraction to expansion with the accelerated expansion at late times. The fine-tuned Friedman-Robertson-Walker singular solution is a particular limiting case at the lower boundary of existence of regular oscillating solutions in the absence of vector fields. The simplicity of the general covariant expression for the energy-momentum tensor allows displaying the main properties of the dark sector analytically. Although the physical nature of dark sector is still unknown, the macroscopic theory can help analyze the role of dark matter in astrophysical phenomena without resorting to artificial model assumptions.

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16

Khlopov, Maxim. "Cosmoparticle Physics of Dark Universe". Symmetry 14, n. 1 (9 gennaio 2022): 112. http://dx.doi.org/10.3390/sym14010112.

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The physics of the dark Universe goes beyond the standard model (BSM) of fundamental interactions. The now-standard cosmology involves inflation, baryosynthesis and dark matter/energy corresponding to BSM physics. Cosmoparticle physics offers cross disciplinary study of the fundamental relationship of cosmology and particle physics in the combination of its physical, astrophysical and cosmological signatures. Methods of cosmoparticle physics in studies of BSM physics in its relationship with inevitably nonstandard features of dark universe cosmology are discussed. In the context of these methods, such exotic phenomena as primordial black holes, antimatter stars in baryon asymmetrical Universe or multi-charged constituents of nuclear interacting atoms of composite dark matter play the role of sensitive probes for BSM models and their parameters.

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17

Farnes, J. S. "A unifying theory of dark energy and dark matter: Negative masses and matter creation within a modified ΛCDM framework". Astronomy & Astrophysics 620 (dicembre 2018): A92. http://dx.doi.org/10.1051/0004-6361/201832898.

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Dark energy and dark matter constitute 95% of the observable Universe. Yet the physical nature of these two phenomena remains a mystery. Einstein suggested a long-forgotten solution: gravitationally repulsive negative masses, which drive cosmic expansion and cannot coalesce into light-emitting structures. However, contemporary cosmological results are derived upon the reasonable assumption that the Universe only contains positive masses. By reconsidering this assumption, I have constructed a toy model which suggests that both dark phenomena can be unified into a single negative mass fluid. The model is a modified ΛCDM cosmology, and indicates that continuously-created negative masses can resemble the cosmological constant and can flatten the rotation curves of galaxies. The model leads to a cyclic universe with a time-variable Hubble parameter, potentially providing compatibility with the current tension that is emerging in cosmological measurements. In the first three-dimensional N-body simulations of negative mass matter in the scientific literature, this exotic material naturally forms haloes around galaxies that extend to several galactic radii. These haloes are not cuspy. The proposed cosmological model is therefore able to predict the observed distribution of dark matter in galaxies from first principles. The model makes several testable predictions and seems to have the potential to be consistent with observational evidence from distant supernovae, the cosmic microwave background, and galaxy clusters. These findings may imply that negative masses are a real and physical aspect of our Universe, or alternatively may imply the existence of a superseding theory that in some limit can be modelled by effective negative masses. Both cases lead to the surprising conclusion that the compelling puzzle of the dark Universe may have been due to a simple sign error.

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18

Abbas, S. Z., H. H. Shah, W. Chammam, H. Sun, Wasim Ul Haq e H. Shah. "The curvature effect on the gravitational collapse of interacting and non-interacting combination of dark matter and dark energy". International Journal of Modern Physics A 35, n. 17 (3 giugno 2020): 2050078. http://dx.doi.org/10.1142/s0217751x20500785.

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The study of gravitational collapse is a very interesting phenomena in general relativistic astrophysics. Here, in this study we investigated the gravitational collapse of a spherically symmetric core of a star, constituted of dark matter (DM) ([Formula: see text]), in dark energy (DE) ([Formula: see text]) background. It was investigated that gravitational collapse of interacting and noninteracting combination of DM and DE yields BH formation. In this work, our main aim is to examine the effect of space–time curvature [Formula: see text] on the gravitational collapse of interacting and noninteracting combination of dark matter and DE. We achieve the visible influence of curvature on gravitational collapse analytically and interpret the results graphically.

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Osano, Bob, e Timothy Oreta. "Multi-fluid theory and cosmology: A convective variational approach to interacting dark-sector". International Journal of Modern Physics D 28, n. 06 (aprile 2019): 1950078. http://dx.doi.org/10.1142/s0218271819500780.

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The interaction of dark energy and dark matter has been studied widely using various formalisms in an effort to understand the physics of such gravitational interactions. Such studies are motivated by the idea that they might hold the key to resolving some of the outstanding problems in cosmology. We will consider the relativistic convective variational formalism in our study of dark matter (hereafter DM)-dark energy (hereafter DE) interaction. In particular, we go beyond the gravitational interaction and consider the potential entrainment phenomena involving the two dark-sector constituents. Ours is a formalism paper and focuses on the theoretical considerations that inform the modeling of such interactions.

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Aristov, V. V. "RELATIONAL STATISTICAL SPACE-TIME FOR COSMOLOGICAL SCALES". Metafizika, n. 2 (15 dicembre 2020): 62–70. http://dx.doi.org/10.22363/2224-7580-2020-2-62-70.

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The relational statistical approach is used in the study of phenomena of macroscopic cosmological scales. In fact, a variant of the generalized Mach’s principle is developing. Theoretical models of Dark matter as well as Dark energy without introducing additional particles and forces are discussed. Changes in the ordinary kinematic and dynamic equations for ultra-ultra-high speeds are considered. Some new effects are predicted at such energy scales.

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21

Gough, Michael Paul. "Information Dark Energy Can Resolve the Hubble Tension and Is Falsifiable by Experiment". Entropy 24, n. 3 (9 marzo 2022): 385. http://dx.doi.org/10.3390/e24030385.

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We consider the role information energy can play as a source of dark energy. Firstly, we note that if stars and structure had not formed in the universe, elemental bits of information describing the attributes of particles would have exhibited properties similar to the cosmological constant. The Landauer equivalent energy of such elemental bits would be defined in form and value identical to the characteristic energy of the cosmological constant. However, with the formation of stars and structure, stellar heated gas and dust now provide the dominant contribution to information energy with the characteristics of a dynamic, transitional, dark energy. At low redshift, z < ~1.35, this dark energy emulates the cosmological constant with a near-constant energy density, w = −1.03 ± 0.05, and an energy total similar to the mc2 of the universe’s ∼1053 kg of baryons. At earlier times, z > ~1.35, information energy was phantom, differing from the cosmological constant, Λ, with a CPL parameter difference of ∆wo = −0.03 ± 0.05 and ∆wa = −0.79 ± 0.08, values sufficient to account for the H0 tension. Information dark energy agrees with most phenomena as well as Λ, while exhibiting characteristics that resolve many tensions and problems of ΛCDM: the cosmological constant problem; the cosmological coincidence problem; the H0 tension, and the σ8 tension. As this proposed dark energy source is not usually considered, we identify the expected signature in H(a) that will enable the role of information dark energy to be falsified by experimental observation.

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Bandyopadhyay, Tanwi, e Ujjal Debnath. "Accretions of Tsallis, Rényi and Sharma–Mittal dark energies onto higher-dimensional Schwarzschild black hole and Morris–Thorne wormhole". Modern Physics Letters A 36, n. 12 (24 marzo 2021): 2150081. http://dx.doi.org/10.1142/s0217732321500814.

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In this work, we study the dark energy accretion phenomena onto [Formula: see text]-dimensional Schwarzschild black hole and [Formula: see text]-dimensional Morris–Thorne wormhole. We obtain the [Formula: see text]-dimensional Schwarzschild black hole mass and [Formula: see text]-dimensional Morris–Thorne wormhole mass and their rate of change of masses due to accretion. For the dark energy component, we consider Tsallis, modified Rényi and “modified” Sharma–Mittal holographic dark energy (HDE) and new agegraphic dark energy (NADE). We also find the black hole mass and the wormhole mass in terms of redshift when cold dark matter and the specified forms of dark energies accrete onto them. In most cases, the black hole mass increases, and wormhole mass decreases for HDE and NADE accretions. The only exception is the Sharma–Mittal NADE, where the black hole mass decreases and wormhole mass increases during the evolution of the Universe. However, the slope of increasing/decreasing mass significantly depends on the dimension in almost all cases.

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Golwala, Sunil R., e Enectali Figueroa-Feliciano. "Novel Quantum Sensors for Light Dark Matter and Neutrino Detection". Annual Review of Nuclear and Particle Science 72, n. 1 (26 settembre 2022): 419–46. http://dx.doi.org/10.1146/annurev-nucl-102020-112133.

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The fields of light dark matter and neutrino physics offer compelling signals at recoil energies of eV to even meV, well below the [Formula: see text] keV thresholds of many techniques currently employed in these fields. Sensing of such small energies can benefit from the emergence of so-called quantum sensors, which employ fundamentally quantum mechanical phenomena to transduce energy depositions into electrical signals. This review focuses on quantum sensors under development that will enhance and extend the search for “particle-like” interactions of dark matter or enable new measurements of neutrino properties in the coming years.

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Gopych, M., H. D. Gräf, U. Laier, W. F. O. Müller, M. Platz, A. Richter, S. Setzer, A. Stascheck, S. Watzlawik e T. Weiland. "Study of dark current phenomena in a superconducting accelerating cavity at the S-DALINAC". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 539, n. 3 (marzo 2005): 490–98. http://dx.doi.org/10.1016/j.nima.2004.11.001.

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Lagouri, Theodota. "Review on Higgs hidden-dark sector physics". Physica Scripta 97, n. 2 (13 gennaio 2022): 024001. http://dx.doi.org/10.1088/1402-4896/ac42a6.

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Abstract The Standard Model (SM), while extremely powerful as a description of the strong, electromagnetic and weak interactions, does not provide a natural candidate to explain Dark Matter (DM). Theoretical as well as experimental motivation exists for the existence of a hidden or dark sector of phenomena that couples either weakly or in a special way to SM fields. Hidden sector or dark sector states appear in many extensions to SM to provide a particular candidate DM in the universe or to explain astrophysical observations. If there is such a family of Beyond the Standard Model (BSM) particles and interactions, they may be accessible experimentally at the Large Hadron Collider (LHC) at CERN and at future High Energy Colliders. In this paper, the main focus is given on selected searches conducted at LHC experiments related to Higgs Hidden-Dark Sector Physics. The current constraints and future prospects of these studies are summarized.

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GALLO, EMANUEL, e OSVALDO M. MORESCHI. "PECULIAR ANISOTROPIC STATIONARY SPHERICALLY SYMMETRIC SOLUTION OF EINSTEIN EQUATIONS". Modern Physics Letters A 27, n. 09 (21 marzo 2012): 1250044. http://dx.doi.org/10.1142/s0217732312500447.

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Motivated by studies on gravitational lenses, we present an exact solution of the field equations of general relativity, which is static and spherically symmetric, has no mass but has a nonvanishing spacelike components of the stress–energy–momentum tensor. In spite of its strange nature, this solution has nontrivial descriptions of gravitational effects. We show that the main aspects found in the dark matter phenomena can be satisfactorily described by this geometry. We comment on the relevance it could have to consider nonvanishing spacelike components of the stress–energy–momentum tensor ascribed to dark matter.

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HWANG, W.-Y. P. "PHASE TRANSITIONS, DOMAIN WALLS, AND DARK MATTER". Modern Physics Letters A 19, n. 13n16 (30 maggio 2004): 1055–62. http://dx.doi.org/10.1142/s0217732304014367.

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We discuss possible roles in the Early Universe of the electroweak (EW) phase transition, which endows masses to the various particles, and the QCD phase transition, which gives rise to quark confinement and chiral symmetry breaking. Both phase transitions are well-established phenomena in the standard model of particle physics. Presumably, the EW phase transition would have taken place in the early universe at around 10-11sec, or at the temperature of about 300 GeV while QCD phase transition occurred between 10-5sec and 10-4sec, or at about 150 MeV. In this article, I wish to model the EW or QCD phase transition in the early universe as driven by a complex scalar field with spontaneous symmetry breaking such that the continuous degeneracy of the true ground states can be well represented. Specific interest has been directed to nucleation of domains, production of domain walls, and subsequent re-organization of domain walls resulting in "domain-wall nuggets". It is suggested that the domain-wall nuggets contribute to dark matter in the present Universe.

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Mahanta, K. L., A. K. Biswal e P. K. Sahoo. "Bianchi type-III dark energy models with constant deceleration parameter in self-creation cosmology". Canadian Journal of Physics 92, n. 4 (aprile 2014): 295–301. http://dx.doi.org/10.1139/cjp-2013-0490.

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We have constructed dark energy cosmological models in an anisotropic Bianchi type-III space–time with a variable equation of state (EoS) parameter ω in Barber’s (Gen. Relativ. Gravitation, 14, 117, 1982) second self-creation theory of gravitation. The models are obtained using the special law of variation of Hubble’s parameter that yields a constant value of the deceleration parameter. In the two different models that we have obtained, the EoS parameter ω for dark energy is found to be time dependent. In one model the value of ω is in good agreement with the recent observations of type Ia supernovae (SNe Ia) data, SNe Ia data with cosmic microwave background radiation anisotropy and galaxy clustering statistics. Further we have discussed the well-known astrophysical phenomena, namely, the Hubble parameter H(z), luminosity distance dL, proper distance d(z), distance modulus μ(z), and look-back time with red shift. The expression for jerk parameter and statefinder parameters are also derived.

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Berezhiani, Zurab. "Matter, dark matter, and antimatter in our Universe". International Journal of Modern Physics A 33, n. 31 (10 novembre 2018): 1844034. http://dx.doi.org/10.1142/s0217751x18440347.

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I discuss the possibility of dark matter conversion into our antimatter, assuming that a part of dark matter is represented by a hypothetical mirror matter. In the Early Universe, [Formula: see text] and [Formula: see text] violating interactions between the particles of ordinary and mirror worlds can co-generate their baryon asymmetries in comparable amounts, [Formula: see text], also predicting the sign of mirror baryon asymmetry. At low energies, the same interactions induce particle mixing phenomena between two sectors. In this way, e.g. mirror neutron [Formula: see text] should oscillate into our antineutron [Formula: see text], with probability that depends on environmental conditions as matter density and magnetic fields. This oscillation can be faster than the neutron decay itself, with [Formula: see text] conversion rate accessible for the experimental search. It can have fascinating phenomenological and astrophysical consequences, and can potentially open an unlimited source of energy by transforming dark mirror matter into antimatter in a controllable way.

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Learned, John G., e Karl Mannheim. "High-Energy Neutrino Astrophysics". Annual Review of Nuclear and Particle Science 50, n. 1 (dicembre 2000): 679–749. http://dx.doi.org/10.1146/annurev.nucl.50.1.679.

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▪ Abstract High-energy (>100 MeV) neutrino astrophysics enters an era of opportunity and discovery as the sensitivity of detectors approaches astrophysically relevant flux levels. We review the major challenges for this emerging field, among which the nature of dark matter, the origin of cosmic rays, and the physics of extreme objects such as active galactic nuclei, gamma-ray bursts, pulsars, and supernova remnants are of prime importance. Variable sources at cosmological distances allow the probing of neutrino propagation properties over baselines up to about 20 orders of magnitude larger than those probed by terrestrial long-baseline experiments. We review the possible astrophysical sources of high-energy neutrinos, which also act as an irreducible background to searches for phenomena at the electroweak and grand-unified-theory symmetry-breaking scales related to possible supersymmetric dark matter and topological defects. Neutrino astronomy also has the potential to discover previously unimagined high-energy sources invisible in other channels and provides the only means for direct observations of the early universe prior to the era of decoupling of photons and matter. We conclude with a discussion of experimental approaches and a short report on present projects and prospects. We look forward to the day when it will be possible to see the universe through a new window in the light of what may be its most numerous particle, the elusive neutrino.

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31

BURKO, LIOR M. "BLACK HOLE SINGULARITIES, CRITICAL PHENOMENA, THE RUNAWAY UNIVERSE AND HYPERSPACE TRAVEL". International Journal of Modern Physics D 12, n. 09 (ottobre 2003): 1675–80. http://dx.doi.org/10.1142/s0218271803004067.

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Black holes are always irradiated by the cosmic background radiation. This captured radiation field determines the physical and geometrical nature of the singularity inside the black hole. We find that non-compact radiation fields (similar to the cosmic background radiation) affect dramatically the singularity, and may determine the fate of a falling astronaut. In particular, the dark energy which accelerates the expansion of the universe determines whether the "tunnel" inside the black hole is blocked, or whether the possibility of using the black hole as a portal for hyperspace travel cannot be ruled out as yet.

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32

Guescini, Francesco. "Searches for new phenomena with the ATLAS detector". International Journal of Modern Physics A 35, n. 34n35 (18 dicembre 2020): 2044005. http://dx.doi.org/10.1142/s0217751x20440054.

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Many theories beyond the Standard Model predict new phenomena accessible by the Lhc. Searches for new physics are performed using the Atlas experiment at the Lhc focusing on exotic signatures that are predicted in several theories, excluding supersymmetry. The results of recent searches using 13 TeV data, with the exception of those for Dark Matter signatures, and their interplay and interpretation are presented. Prospects for searches at the High Luminosity Lhc are also discussed.

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33

KARLE, ALBRECHT. "NEUTRINO ASTRONOMY AT THE SOUTH POLE". Modern Physics Letters A 28, n. 02 (20 gennaio 2013): 1340004. http://dx.doi.org/10.1142/s021773231340004x.

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The origin of highest energy cosmic rays remains unresolved. High-energy neutrinos may provide the clues to fundamental phenomena such as the origin of cosmic rays or dark matter in the Universe. The IceCube Neutrino Observatory, a km scale neutrino detector, has come into full operation in 2011. At the highest energy levels, prototypes of a new experiment, the Askaryan Radio Array, have been deployed and are being tested. We report on the status, first results and prospects of the experimental neutrino searches under way and planned at the South Pole.

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34

Bartlett, Rodney. "HOW MULTIPLE BRANCHES OF MATHEMATICS UNITE THE MOBIUS STRIP WITH MULTIPLE PHENOMENA IN PHYSICS AND COSMOLOGY". IJRDO -JOURNAL OF MATHEMATICS 9, n. 8 (25 agosto 2023): 1–9. http://dx.doi.org/10.53555/m.v9i8.5852.

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Question – How does the Riemann Hypothesis Support Topological Propulsion and Faster-than-light Travel? Answer – a) Using the axiom that there indeed are infinitely many nontrivial zeros on the critical line (calculations have confirmed the hypothesis to be true to over 13 trillion places), the critical line is identified as the y-axis of Wick rotation. This suggests the y-axis is literally infinite and that infinity equals zero. In this case, it is zero distance in time and space. Travelling zero distance is done instantly and is therefore faster-than-light travel. b) Wick rotation is essential to this article’s description of a topological (mathematical) universe and the Riemann hypothesis’ identification with Wick means the hypothesis doesn’t just apply to the distribution of prime numbers but also applies to the fundamental structure of the mathematical universe’s space-time. An absolutely essential ingredient of time travel by applied maths is being able to journey into the remote past and future. For this reason, a paragraph about the coexistence of past, present, and future (without such coexistence, time travel could never be a possibility) is included in a section titled “Riemann Hypothesis and Wick Rotation Support Time Travel into the Past and Future”. This article provides insights into travelling at significant fractions of – as well as faster than - light, the Higgs boson and field, electroweak interaction, dark matter, dark energy, other dimensions, space-time (eg the expanding-universe question and time travel), quantum mechanics, quantum computers, the Riemann hypothesis, and Unidentified Flying Objects. The article is also a brief summary discussing how the Matrix, the Riemann hypothesis, quaternions, Wick rotation, and imaginary numbers unite topology’s Mobius strip with known and unknown dimensions as well as the Higgs boson, Higgs field, dark matter, dark energy, antigravitons, and the static universe. The article also explains Unidentified Flying Objects as the result of future human technology.

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35

Hirbu, Arefa, Pavel Topala e Alexandr Ojegov. "Secondary Radiation in Color Optical Filter Glasses by the Action of Plasma". Advanced Materials Research 1036 (ottobre 2014): 158–63. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.158.

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This paper presents the results of experimental investigations and theoretical analysis of secondary physical phenomena that occur at interaction of electrical discharges in impulse (EDI) plasma radiation with color optical filter glasses. It was established that infrared filters (of type IKS) emit a violet secondary radiation, and dark filter (of type TS) emits a green secondary radiation. Detected phenomena can be explained by secondary radiation emission due to multi-photonic excitation of SiO2 molecules and direct-inverse translating from one energy level to another. One of the resonance oscillatory levels (of the absorption bands) for molecules of SiO2 is 780 cm-1. Thus, for infrared filters the number of absorbed infrared photons is 33, and for dark glasses is 24. In this case, the wave length of secondary radiation is 388.5 nm (violet color) and 534.2 nm (green color) respectfully. This phenomenon can be applied in construction of equipment functioning based on monochromatic light radiation.

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36

Danielewski, Marek. "The Planck – Kleinert Crystal". Zeitschrift für Naturforschung A 62, n. 10-11 (1 novembre 2007): 564–68. http://dx.doi.org/10.1515/zna-2007-10-1102.

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The Planck -Kleinert Crystal hypothesis is analyzed for an ideal cubic fcc crystal formed by Planck particles. In this type of a quasi-continuum the energy, momentum, and mass transport are described by the classical balance equations. The transverse wave is the electromagnetic wave, and its velocity equals the velocity of light. The quasi-stationary collective movement of mass in the crystal is equivalent to the particle (body), and such an approach enables derivation of the Schrödinger equation. The diffusing interstitial Planck particles create a gravity field, and the computed value of G is within the accuracy of experimental data. The model predicts four different force fields and a vast amount of the “dark matter and dark energy” in the crystal lattice. It allows for a self-consistent interpretation of multiscale phenomena.

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37

ONOFRIO, ROBERTO. "HIGH-ENERGY DENSITY IMPLICATIONS OF A GRAVITOWEAK UNIFICATION SCENARIO". Modern Physics Letters A 29, n. 01 (7 gennaio 2014): 1350187. http://dx.doi.org/10.1142/s0217732313501873.

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We discuss how a scenario recently proposed for the morphing of macroscopic gravitation into weak interactions at the attometer scale affects our current understanding of high-energy density phenomena. We find that the Yukawa couplings of the fundamental fermions are directly related to their event horizons, setting an upper bound [Formula: see text] for their observability through gauge interactions. Particles with larger Yukawa couplings are not precluded, but should interact only gravitationally, providing a natural candidate for dark matter. Furthermore, the quantum vacuum contribution to the cosmological constant is reduced by several orders of magnitude with respect to the current estimates. The expected running of the Newtonian gravitational constant could provide a viable alternative scenario to the inflationary stage of the Universe.

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38

Kuzmich, Soika Alexander. "Revisiting the nature of dark sunspots: not magnetic, but thermal activity of the Sun". Physics & Astronomy International Journal 6, n. 3 (9 agosto 2022): 90–95. http://dx.doi.org/10.15406/paij.2022.06.00258.

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This article is a continuation of the works1-4 of the author, devoted to elucidating the physical nature of dark sunspots. It has been proven that the scientific paradigm of dark cold sunspots prevailing in solar physics is erroneous, since it contradicts the second law of thermodynamics. It has been proven that dark sunspots in the solar photosphere can only be hotter than the photosphere, and their visual darkness is of a non-thermal nature. Sunspots are the hottest areas of the Sun's surface, the temperature of which is ~ 6∙106 K, and they are the cause and sources of thermal energy of solar activity phenomena. The physical and empirical inconsistency of the concept of the magnetic activity of the Sun and the processes of magnetic reconnection in the solar atmosphere is proved. All unsolved problems of solar physics, including the heating of the corona, are due to the false paradigm of cold sunspots.

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39

GIGLIETTO, N. "STATUS AND PERSPECTIVES OF GLAST GAMMA RAY EXPERIMENT". International Journal of Modern Physics A 20, n. 29 (20 novembre 2005): 7009–11. http://dx.doi.org/10.1142/s0217751x05030703.

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GLAST, the Gamma-ray Large Area Telescope, is a satellite-based experiment able to measure the cosmic gamma-ray flux in the energy range between 20 MeV and 300 GeV or above. The sensitivity is more than 30 times respect to EGRET and the good spatial and time resolution over a large field of view let us to cover a large variety of high energy phenomena. In particular GLAST will be able to study both diffuse emission and point-like gamma ray sources, including active galactic nuclei, gamma ray bursts, pulsars and supernova remnants. In addition, the potentialities of GLAST to explore rare or exotic phenomena like supersymmetric dark matter annihilations will be shown. The present knowledge of the science opportunities that the GLAST experiment can explore will be completed with the detector description and the current status of the experiment.

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40

Schwartz, Charles. "Tachyon Interactions". Symmetry 15, n. 1 (11 gennaio 2023): 209. http://dx.doi.org/10.3390/sym15010209.

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A consistent theory of free tachyons has shown how tachyon neutrinos can explain major cosmological phenomena, dark energy and dark matter. Now, we investigate how tachyon neutrinos might interact with other particles: the weak interactions. Using the quantized field operators for electrons and tachyon neutrinos, the simplest interaction shows how the chirality selection rule, put in by force in the Standard Model, comes out naturally. Then, I wander into a re-study of what we do with negative frequencies of plane wave solutions of relativistic wave equations. The findings are simple and surprising, leading to a novel understanding of how to construct quantum field theories.

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41

Kumar, Mukesh, Manvinder Singh, Mohit Bajaj, Hossam Kotb e Djeudjo Temene Hermann. "LRS Bianchi Type-I String Cosmological Models in f Q Gravity". Journal of Mathematics 2023 (27 giugno 2023): 1–18. http://dx.doi.org/10.1155/2023/7016804.

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In the current study, we studied a f Q -gravitational, anisotropic, locally rotationally symmetric (LRS), Bianchi type-I spacetime universe. We have adopted the freely chosen function f Q = Q + α Q , where α is a model-free parameter. We assumed that the universe is filled with dusty string fluid and that the shear scalar ( σ ) and the expansion scalar ( θ ) are proportional to each other in order to solve field equations for the average Hubble parameter ( H ). The resultant Hubble function has been fitted with observational datasets H z and SNe Ia datasets of apparent magnitude m z in order to obtain the best fit values for the cosmological parameters. Utilizing these best fit values throughout the analysis, many cosmic phenomena are examined. We have investigated cosmographic coefficients such as H , q , j , a n d s to see if an accelerated transit phase dark energy model of the cosmos exists. Also, we have classified the dark energy models that are explored using Om diagnostic analysis; our universe model is a quintessential dark energy model. The age of the universe as it exists right now has been roughly calculated by the model.

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42

Pradhan, Anirudh, Archana Dixit e Shilpi Singhal. "Anisotropic MHRDE model in BD theory of gravitation". International Journal of Geometric Methods in Modern Physics 16, n. 12 (22 novembre 2019): 1950185. http://dx.doi.org/10.1142/s0219887819501858.

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In this paper, in the framework of the Brans–Dicke [Phys. Rev. 124 (1961) 925] Gravitation theory, we propose to study the spatially homogeneous, anisotropic and axially symmetric model filled with dark matter and dark energy. Here, we consider the modified holographic Ricci dark energy proposed by Chen and Jing [Phys. Rev. B 679 (2009) 144] as a feasible state of darkness. To achieve a solution, we consider the time-dependent deceleration parameter, which contributes to the average scale factor of [Formula: see text], where [Formula: see text] and [Formula: see text] are arbitrary constants. We have derived field equations of Brans–Dicke theory of gravitation with the help of an axially symmetric anisotropic Bianchi-type space-time. We have determined the cosmological parameters, namely, deceleration parameter, matter energy density, anisotropic dark energy density, BD scalar field, skewness parameter, EoS parameter and jerk parameter. Here, the various phenomena like the Big Bang, expanding the universe, and shift from anisotropy to isotropy are observed in the model. A comprehensive physical debate of these dynamic parameters is provided through a graphical representation. We observe that we have a quintessence model that exhibits a smooth transition from decelerated stage to an accelerated phase of the universe. This situation is in complete agreement with the modern cosmology scenario. Some physical and geometric behaviors are also discussed and discovered to be in excellent agreement with SNe Ia Supernova’s latest observations.

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43

BEAUCHEMIN, PIERRE-HUGUES, e REYHANEH REZVANI. "MONOJET EVENTS: FROM DARK MATTER TO EXTRA DIMENSIONS, A SEARCH FOR THE EXOTICS USING THE STANDARD MODEL". International Journal of Modern Physics A 28, n. 08 (21 marzo 2013): 1330012. http://dx.doi.org/10.1142/s0217751x13300123.

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Monojet events consist in event topologies with a high transverse momentum jet and a large amount of missing transverse energy. They constitute a promising final state that could lead to phenomena beyond the Standard Model. The theoretical models giving rise to such a signature include the pair production of Weakly Interacting Massive Particles, as dark matter candidates, and models of large extra dimensions. Monojet events can even be used to measure the Standard Model properties of Z boson decays, provided that the precision of the analysis is high enough. Such precision can be achieved by using data-driven determinations of the Standard Model contributions to monojet events. Exotics searches for new physics in such a final state have been performed at all high energy hadronic collider experiments since SPS. The ATLAS and CMS analyses with 7 TeV LHC data provide the latest and most useful information obtained from monojet studies. Their results are presented and discussed in this review paper.

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44

KAJINO, TOSHITAKA, MOTOHIKO KUSAKABE, KAZUHIKO KOJIMA, TAKASHI YOSHIDA, DAI G. YAMAZAKI, KIYOTOMO ICHIKI e GRANT J. MATHEWS. "NEUTRINO MASS AND COLD DARK MATTER PARTICLES IN BIG-BANG NUCLEOSYNTHESIS". Modern Physics Letters A 23, n. 27n30 (30 settembre 2008): 2427–42. http://dx.doi.org/10.1142/s021773230802954x.

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Neutrino is a tiny weakly interacting massive particle, but it has strong impacts on various cosmological and astrophysical phenomena. Neutrinos play a critical role in nucleosynthesis of light-to-heavy mass elements in core-collapse supernovae. The light element synthesis is particularly affected by neutrino oscillation (MSW) effect through the ν-process. We propose first that precise determination of sin 2 2θ13 and mass hierarchy can be made by a theoretical study of the observed 7 Li /11 B ratio in stars and presolar grains which are produced from SN ejecta. Theoretical sensitivity in our proposed method is shown to be superior to ongoing long-baseline neutrino experiments for the parameter region 10−4 ≤ sin22θ13 ≤ 10−2. We secondly discuss how to constrain the neutrino mass Σmν from precise analysis of cosmic microwave background anisotropies in the presence of primordial magnetic field. We obtain an upper limit Σmν < 1.3 eV (2σ). Thirdly, we discuss decaying dark-matter particle model in order to solve the primordial lithium problems that the standard Big-Bang nucleosynthesis theory predicts extremely different 6 Li and 7 Li abundances from observations.

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45

Cacciatori, Sergio L., Alessio Marrani e Federico Re. "On generalized Lemaitre–Tolman–Bondi metric: Fractal matter at the end of matter–antimatter recombination". International Journal of Modern Physics D 30, n. 11 (agosto 2021): 2150086. http://dx.doi.org/10.1142/s0218271821500863.

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Many recent researches have investigated the deviations from the Friedmannian cosmological model, as well as their consequences on unexplained cosmological phenomena, such as dark matter and the acceleration of the Universe. On one hand, a first-order perturbative study of matter inhomogeneity returned a partial explanation of dark matter and dark energy, as relativistic effects due to the retarded potentials of far objects. On the other hand, the fractal cosmology, now approximated by a Lemaitre–Tolman–Bondi (LTB) metric, results in distortions of the luminosity distances of SNe Ia, explaining the acceleration as apparent. In this work, we extend the LTB metric to ancient times. The origin of the fractal distribution of matter is explained as the matter remnant after the matter–antimatter recombination epoch. We show that the evolution of such a inhomogeneity necessarily requires a dynamical generalization of LTB, and we propose a particular solution.

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46

WANG, D. L., e X. H. YAN. "SOLITON ON THE SEMI-INFINITE BAND GAP OF BEC IN AN OPTICAL LATTICE". International Journal of Modern Physics B 25, n. 06 (10 marzo 2011): 781–93. http://dx.doi.org/10.1142/s0217979211058250.

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By developing a multiple-scale method, we study analytically the dynamics of the soliton inside the semi-infinite band gap (SIBG) of quasi-one-dimensional Bose–Einstein condensates trapped in an optical lattice. In the linear case, a stable condition of soliton formation is obtained. For a weak nonlinearity, whether there occurs a spatially propagating or localized gap soliton is determined by the lattice depth. Meanwhile, we predict the existence of the dark (bright) gap solitons for the repulsive (attractive) interactions in the SIBG, different from that of the gap solitons in other energy gaps. And the collision of two dark (or bright) solitons is nearly elastic under a safe range of atomic numbers. An experimental protocol is further designed for observing these phenomena.

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47

Du, Wen-Yuan, Bing-Hong Wang e Shu-Min Li. "Nonlinear effects in the laser-assisted scattering of a positron by a muon". Modern Physics Letters B 32, n. 05 (20 febbraio 2018): 1850058. http://dx.doi.org/10.1142/s0217984918500586.

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Abstract (sommario):

The scattering of a positron by a muon in the presence of a linearly polarized laser field is investigated in the first Born approximation. The theoretical results reveal: (1) At large scattering angle, an amount of multiphoton processes take place in the course of scattering. The photon emission processes predominate the photon absorption ones. (2) Some nonlinear phenomena about oscillations, dark angular windows, and asymmetry can be observed in angular distributions. We analyze the cause giving rise to dark windows and geometric asymmetry initially noted in the potential scattering. (3) We also analyze the total differential cross-section, the result shows that the larger the incident energy is, the smaller the total differential cross-section is. The reasons of these new results are analyzed.

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48

De Laurentis, Mariafelicia, e Ivan De Martino. "Probing the physical and mathematical structure of f(R)-gravity by PSR J0348 + 0432". International Journal of Geometric Methods in Modern Physics 12, n. 04 (aprile 2015): 1550040. http://dx.doi.org/10.1142/s0219887815500401.

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Abstract (sommario):

There are several approaches to extend General Relativity in order to explain the phenomena related to the Dark Matter and Dark Energy. These theories, generally called Extended Theories of Gravity, can be tested using observations coming from relativistic binary systems as PSR J0348 + 0432. Using a class of analytical f(R)-theories, one can construct the first time derivative of orbital period of the binary systems starting from a quadrupolar gravitational emission. Our aim is to set boundaries on the parameters of the theory in order to understand if they are ruled out, or not, by the observations on PSR J0348 + 0432. Finally, we have computed an upper limit on the graviton mass showing that agree with constraint coming from other observations.

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49

Foot, R. "Mirror dark matter: Cosmology, galaxy structure and direct detection". International Journal of Modern Physics A 29, n. 11n12 (25 aprile 2014): 1430013. http://dx.doi.org/10.1142/s0217751x14300130.

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Abstract (sommario):

A simple way to accommodate dark matter is to postulate the existence of a hidden sector. That is, a set of new particles and forces interacting with the known particles predominantly via gravity. In general, this leads to a large set of unknown parameters, however, if the hidden sector is an exact copy of the standard model sector, then, an enhanced symmetry arises. This symmetry, which can be interpreted as space–time parity, connects each ordinary particle (e, ν, p, n, γ, …) with a mirror partner (e′, ν′, p′, n′, γ′, …). If this symmetry is completely unbroken, then the mirror particles are degenerate with their ordinary particle counterparts, and would interact amongst themselves with exactly the same dynamics that govern ordinary particle interactions. The only new interaction postulated is photon–mirror photon kinetic mixing, whose strength ϵ, is the sole new fundamental (Lagrangian) parameter relevant for astrophysics and cosmology. It turns out that such a theory, with suitably chosen initial conditions effective in the very early universe, can provide an adequate description of dark matter phenomena provided that ϵ~10-9. This review focusses on three main developments of this mirror dark matter theory during the last decade: early universe cosmology, galaxy structure and the application to direct detection experiments.

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50

Gorkavenko, V. M. "Search for Hidden Particles in Intensity Frontier Experiment SHiP". Ukrainian Journal of Physics 64, n. 8 (18 settembre 2019): 689. http://dx.doi.org/10.15407/ujpe64.8.689.

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Abstract (sommario):

Despite the undeniable success of the Standard Model of particle physics (SM), there are some phenomena (neutrino oscillations, baryon asymmetry of the Universe, dark matter, etc.) that SM cannot explain. This phenomena indicate that the SM have to be modified. Most likely, there are new particles beyond the SM. There are many experiments to search for new physics that can be can divided into two types: energy and intensity frontiers. In experiments of the first type, one tries to directly produce and detect new heavy particles. In experiments of the second type, one tries to directly produce and detect new light particles that feebly interact with SM particles. The future intensity frontier SHiP experiment (Search for Hidden Particles) at the CERN SPS is discussed. Its advantages and technical characteristics are given.

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