English
Related papers

Related papers: Non-Extensive Entropy and Power-Law Inflation: Imp…

200 papers

We studied the Sharma-Mittal relative entropy and showed that its physical meaning is the free energy difference between the off-equilibrium and equilibrium distributions. Unfortunately, Sharma-Mittal relative entropy may acquire this…

Statistical Mechanics · Physics 2007-05-23 E. Akturk , G. B. Bagci , R. Sever

We calculate the spectrum of density fluctuations in models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, and specifically investigate the dependence of the predictions on modifications of the…

Astrophysics · Physics 2009-10-31 Robert H. Brandenberger , Jerome Martin

We consider observational limits on a proposed model of the string landscape in inflation. In this scenario, effects from the decoherence of entangled quantum states in long-wavelength modes in the universe result in modifications to the…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-08 William H. Kinney

Fluctuations in the intensity and polarization of the cosmic microwave background (CMB) and the large-scale distribution of matter in the universe each contain clues about the nature of the earliest moments of time. The next generation of…

A new class of gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold are studied in some detail. These models involve…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Eduardo Guendelman , Ramón Herrera , Pedro Labraña , Emil Nissimov , Svetlana Pacheva

A comparative study of one-dimensional quantum structures which allow analytic expressions for the position and momentum R\'{e}nyi $R(\alpha)$ and Tsallis $T(\alpha)$ entropies, focuses on extracting the most characteristic physical…

Quantum Physics · Physics 2019-01-15 O. Olendski

Tensor non-Gaussianity represents an important future probe of the physics of inflation. Inspired by recent works, we elaborate further on the possibility of significant primordial tensor non-Gaussianities sourced by extra fields during…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-20 Emanuela Dimastrogiovanni , Matteo Fasiello , Gianmassimo Tasinato , David Wands

We constrain tilted spatially-flat and untilted nonflat XCDM dynamical dark energy inflation parameterizations using Planck 2015 cosmic microwave background (CMB) anisotropy data and recent baryonic acoustic oscillations distance…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-27 Chan-Gyung Park , Bharat Ratra

In this work, we studied the slow-roll approximation of cosmic inflation within the context of $f(R,T)$ gravity, where $R$ is the scalar curvature, and $T$ is the trace of the energy-momentum tensor. By choosing a minimal coupling between…

General Relativity and Quantum Cosmology · Physics 2021-01-12 Mauricio Gamonal

We study nonlinear cosmological perturbations and their possible non-Gaussian character in an extended non-minimal inflation where gravity is coupled non-minimally to both the scalar field and its derivatives. By expansion of the action up…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Raheleh Shojaee , Kourosh Nozari , Farhad Darabi

The R\'{e}nyi entropy, a one-parameter generalization of Boltzmann-Gibbs entropy, offers a promising framework for probing quantum gravitational effects in cosmology. By modifying the entropy-area relation of the apparent horizon, R\'{e}nyi…

General Physics · Physics 2025-07-22 Ahmad Sheykhi , Ava Shahbazi Sooraki

We study the entanglement entropy between a strip region with width $2R$ and its complement in strongly coupled large-$N$ conformal field theory (CFT) on $\mathbb{R}^{1,n}$ with chemical potential and angular momentum in an thermal…

High Energy Physics - Theory · Physics 2022-09-13 Po-Chun Sun

We derive power spectra of the scalar- and tensor-type structures generated in an inflation model based on a massive non-minimally coupled scalar field with the strong coupling assumption. We make analyses in both the original-frame and the…

Astrophysics · Physics 2009-12-30 J. Hwang , H. Noh

For simple inflationary models, we provide a consistent and complete scheme by which the macro-physical details of early universe inflation may be determined explicitly from the underlying micro-physical theory. We examine inflationary…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Cormier

We generalise Einstein's formulation of the traceless Einstein equations to $f(R)$ gravity theories. In the case of the vacuum traceless Einstein equations, we show that a non-constant Weyl tensor leads via a conformal transformation to a…

General Relativity and Quantum Cosmology · Physics 2020-09-15 John D. Barrow , Spiros Cotsakis

An entropic-force scenario, i.e., entropic cosmology, assumes that the horizon of the universe has an entropy and a temperature. In the present study, in order to examine entropic cosmology, we derive entropic-force terms not only from the…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Nobuyoshi Komatsu , Shigeo Kimura

We consider the non-minimal model of gravity in $Y(R) F^2$-form. We investigate a particular case of the model, for which the higher order derivatives are eliminated but the scalar curvature $R$ is kept to be dynamical via the constraint…

General Relativity and Quantum Cosmology · Physics 2017-11-17 Muzaffer Adak , Ozgur Akarsu , Tekin Dereli , Ozcan Sert

Combining the equivalence between cosmological particle creation and an effective viscous fluid pressure with the fact that the latter represents a dynamical degree of freedom within the second-order Israel-Stewart theory for imperfect…

Astrophysics · Physics 2009-10-31 Winfried Zimdahl

We investigate a generalized entropic cosmology obtained by applying the gravity-thermodynamics conjecture to the Universe horizon using Kaniadakis statistics, namely a relativistic extension of the standard Boltzmann--Gibbs formalism. The…

General Relativity and Quantum Cosmology · Physics 2026-05-21 Abdelhakim Benkrane , Giuseppe Gaetano Luciano

The possibility of linking inflation and late cosmic accelerated expansion using the $\alpha$-attractor models has received increasing attention due to their physical motivation. In the early universe, $\alpha$-attractors provide an…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-21 Carlos García-García , Eric V. Linder , Pilar Ruíz-Lapuente , Miguel Zumalacárregui