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Article
Open AccessCosmological consequences of Brans–Dicke theory in 4D from 5D scalar-vacuum
We study 5D Brans–Dicke theory in the framework of (gravitational) baryogenesis and primordial light element formation. Such a model is able to explain the present cosmic accelerated expansion without recurring t...
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Article
Open AccessSlow-roll inflation and growth of perturbations in Kaniadakis modification of Friedmann cosmology
Kaniadakis entropy is a one-parameter deformation of the classical Boltzmann–Gibbs–Shannon entropy, arising from a self-consistent relativistic statistical theory. Assuming a Kaniadakis-type generalization of ...
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Article
Constraining quantum fluctuations of spacetime foam from BBN
A possibility to describe quantum gravitational fluctuations of the spacetime background is provided by virtual D-branes. These effects may induce a tiny violation of the Lorentz invariance (as well as a possible...
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Article
Open AccessTsallis cosmology and its applications in dark matter physics with focus on IceCube high-energy neutrino data
In this paper we employ a recent proposal of C. Tsallis and formulate the first law of thermodynamics for gravitating systems in terms of the extensive but non-additive entropy. We pay a particular attention t...
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Article
Open AccessSearching for dark matter axions with Berry phase
We discuss novel aspects of the interaction of axions-like particles (ALP) with superfluids, superconductors in particular, and determine an induced Berry phase that is topologically singular and contributes t...
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Article
Open AccessPrecession shift in curvature based extended theories of gravity and quintessence fields
In this paper we constrain the sizes of hypothetical new weak forces by making use the data coming from the precession of Planets. We consider the weak field approximation of Scalar–Tensor Fourth Order Gravity...
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Article
Open AccessNeutrino pair annihilation ( \(\nu {\bar{\nu }}\rightarrow e^-e^+\) ) in the presence of quintessence surrounding a black hole
Quintessence fields, introduced to explain the speed-up of the Universe, might affect the geometry of spacetime surrounding black holes, as compared to the standard Schwarzschild and Kerr geometries. In this f...
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Article
Open AccessCosmological curvature acceleration
Observed accelerated behavior of the Hubble flow, usually related to the existence of a mysterious unknown fluid dubbed dark energy, can be framed in natural extensions of General Relativity that work at infra...
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Article
Open AccessVirial theorem in scalar tensor fourth order gravity
In this paper, we study, in the Newtonian limit, the virial theorem in the context of a scalar tensor fourth order gravity. In particular, we show, that for a isolated galaxy in viral equilibrium, a specific c...
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Article
Open AccessPhoton frequency shift in curvature-based Extended Theories of Gravity
We study the frequency shift of photons generated by rotating gravitational sources in the framework of curvature-based Extended Theories of Gravity. The discussion is developed considering the weak-field appr...
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Article
Open AccessProbing quantum field theory particle mixing and dark-matter-like effects with Rydberg atoms
We analyze the oscillations of Rydberg atoms in the framework of quantum field theory and analyze the analogy with flavor mixing and oscillations. We reveal a non trivial vacuum energy which has the equation o...
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Article
Open AccessNoncommutative Schwarzschild geometry and generalized uncertainty principle
We discuss a possible link between the deformation parameter \(\Theta ^{\mu \nu }\) ...
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Article
Open AccessPeV IceCube signals and Dark Matter relic abundance in modified cosmologies
The discovery by the IceCube experiment of a high-energy astrophysical neutrino flux with energies of the order of PeV, has opened new scenarios in astroparticles physics. A possibility to explain this phenome...
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Open AccessConstraining f(T) teleparallel gravity by big bang nucleosynthesis
We use Big Bang Nucleosynthesis (BBN) observational data on the primordial abundance of light elements to constrain f(T) gravity. The three most studied viable f(T) models, namely the power law, the exponential a...
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Open AccessCosmology with bulk viscosity and the gravitino problem
The gravitino problem is revisited in the framework of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. Dissipative effects (or bulk viscosity effects) ...
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Article
Open AccessThermal relics in cosmology with bulk viscosity
In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bu...
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Article
Consequences of \(f(R)\) theories of gravity on gravitational leptogenesis
\(f(R)\) f ...
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Article
Calculation of the Casimir energy at zero and finite temperature: Some recent results
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Letter: Cerenkov Radiation from a Charged Particle in a Weyl–Dirac Theory
A thin shell can separate an interior region of Riemannian geometry from an exterior spherically symmetric Weyl space. We explore the possibility that a charged particle propagating in the gravitational field ...
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Article
Space-Time Fluctuations Induced by D-Branes and Their Effects on Neutrino Oscillations
Neutrino oscillations are analyzed in the Ellis-Mavromatos-Nanopoulos-Volkov (ENMV) model, where the quantum gravitational fluctuations of the space-time background are described by virtual D branes. Such fluctua...
