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Related papers: Dynamical Evolution of Gravitational Leptogenesis

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It has been recently shown that quantum Boltzman equations may be relevant for leptogenesis. Quantum effects, which lead to a time-dependent CP asymmetry, have been shown to be particularly important for resonant leptogenesis when the…

High Energy Physics - Phenomenology · Physics 2009-03-20 Chee Sheng Fong , M. C. Gonzalez-Garcia

The misalignment mechanism allows for the efficient, and usually very cold, production of light scalar bosons, such as axion-like particles (ALPs), making them an appealing dark matter candidate. However, in certain cases, such as in the…

High Energy Physics - Phenomenology · Physics 2021-02-17 Aleksandr Chatrchyan , Joerg Jaeckel

We consider the cosmological amplification of a metric perturbation propagating in a higher-dimensional Brans-Dicke background, including a non trivial dilaton evolution. We discuss the properties of the spectral energy density of the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 M. Gasperini , M. Giovannini

Based on an extended time-space symmetry, a cylindrical model of gravitational geometrical dynamics with two time-like extra-dimensions leads to a microscopic geodesic description of the curved space-time. Due to interaction of a Higgs-like…

General Physics · Physics 2015-10-15 Vo Van Thuan

Thermal leptogenesis, that can be viewed as a consequence of the seesaw model, is a very natural mechanism to explain the matter anti-matter asymmetry of the Universe. Recently, lepton flavours have been included in the Boltzmann equations,…

High Energy Physics - Phenomenology · Physics 2007-10-11 F. X. Josse-Michaux

I present the theoretical basis for Leptogenesis and its implications for the structure of the universe. It is suggested that density fluctuations grow during the transition period and remnants of this effect should be sought in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. A. Paschos

The evolution equation of cosmic density perturbation of a spin dominated universe in Einstein-Cartan gravity is obtained.Examples of inflationary cosmologies with spin are also given where we compute the density perturbations in terms of…

Astrophysics · Physics 2007-05-23 L. C. Garcia de Andrade

We show that when the relevant CP violating interactions in leptogenesis are fast, the different matter density asymmetries are determined at each instant by a balance condition between the amount of asymmetry being created and destroyed.…

High Energy Physics - Phenomenology · Physics 2015-05-18 Chee Sheng Fong , J. Racker

We introduce a new effect in the neutrino oscillation phase which shows the neutrino-antineutrino oscillation is possible under gravity even if the rest masses of the corresponding eigenstates are same. This is due to CPT violation and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Banibrata Mukhopadhyay

We show how the mechanism recently proposed by Alexander, Peskin, and Sheikh-Jabbari, in which the observed cosmic matter-antimatter asymmetry comes from the contribution of the cosmological tensor perturbations to the gravitational anomaly…

High Energy Physics - Phenomenology · Physics 2007-05-23 David H. Lyth , Yeinzon Rodriguez , Carlos Quimbay

In this work the phenomenology of models possessing a non-minimal coupling between matter and geometry is discussed, with a particular focus on the possibility of describing the flattening of the galactic rotation curves as a dynamically…

Astrophysics of Galaxies · Physics 2015-05-18 Orfeu Bertolami , Jorge Páramos

By combining general relativity and CPT symmetry, the theory of CPT gravity predicts gravitational repulsion between matter and CPT-transformed matter, i.e. antimatter inhabiting an inverted space-time. Such repulsive gravity turned out to…

General Physics · Physics 2025-03-07 Massimo Villata

In a previous paper [1] we considered the possibility that (within the early-radiation epoch) there has been (also) a short period of a significant presence of cosmic strings. During this radiation-plus-strings stage the Universe…

High Energy Physics - Theory · Physics 2015-06-03 Kostas Kleidis , Apostolos Kuiroukidis , Demetrios B. Papadopoulos , Enric Verdaguer

Primordial scalar curvature perturbations ($\zeta$), typically probed on large cosmological scales via CMB and LSS observations, can be significantly enhanced on smaller scales by various early Universe mechanisms, for instance, non-minimal…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-30 Mauro Pieroni

Cosmological simulations of structure formation are invaluable to study the evolution of the Universe and the development of galaxies in it successfully reproducing many observations in the context of the cosmological paradigm $\Lambda$CDM.…

Astrophysics of Galaxies · Physics 2021-02-11 J. M. Pacheco-Arias , C. R. Carvajal-Bohorquez , Juan C. B. Pineda , L. A. Núñez

I review a mechanism for a potential explanation of the dominance of matter over antimatter in the Universe (``our existence''), based on a (3+1)-dimensional string-inspired cosmological model, characterised by (uncancelled) gravitational…

High Energy Physics - Phenomenology · Physics 2024-12-11 Nick E. Mavromatos

Mimetic gravity can be described as a formulation capable of mimicking different evolutionary scenarios regarding the universe dynamics. Notwithstanding its initial aim of producing a similar evolution to the one expected from the dark…

General Relativity and Quantum Cosmology · Physics 2019-05-01 Eunice Bezerra , Oswaldo D. Miranda

Leptogenesis provides an elegant mechanism to explain the observed baryon asymmetry of the Universe (BAU), yet its experimental verification remains challenging due to requirements of either extremely heavy right-handed neutrinos or…

High Energy Physics - Phenomenology · Physics 2025-04-11 Wei Liu , Yongcheng Wu

The review is devoted to consideration of possible observational consequences of modified gravity theories, suggested for explanation of the contemporary accelerated expansion of the universe. The major attention is paid to F(R)-models. It…

General Relativity and Quantum Cosmology · Physics 2019-11-11 Elena Arbuzova

Propagation of fermion in curved space-time generates gravitational interaction due to the coupling between spin of the fermion and space-time curvature. This gravitational interaction, which is an axial-vector appears as CPT violating term…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Banibrata Mukhopadhyay , Parampreet Singh