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Related papers: Periodic cosmic evolution in $f(Q)$ gravity formal…

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A new dynamical paradigm merging quantum dynamics with cosmology is discussed. Time evolution involves a genuine passage of time, which distinguishes the formalism from those where dynamics in space is equivalent to statics in space-time.…

General Physics · Physics 2024-02-01 Marek Czachor

We first discuss a framework for discrete quantum processes (DQP). It is shown that the set of q-probability operators is convex and its set of extreme elements is found. The property of consistency for a DQP is studied and the quadratic…

General Relativity and Quantum Cosmology · Physics 2022-09-01 Stan Gudder

In this article, we study the expanding nature of universe in the contest of $f(R,L_m)$ gravity theory, here $ R $ represents the Ricci scalar and $ L_m $ is the matter Lagrangian density. With a specific form of $ f(R,L_m) $, we obtain the…

General Relativity and Quantum Cosmology · Physics 2023-06-28 J. K. Singh , Shaily , Ratbay Myrzakulov , Harshna Balhara

The dynamical equations which are basic for the description of the dynamics of quantum felds in arbitrary space--time geometries, can be derived from the requirements of a unique deterministic evolution of the quantum fields, the…

General Relativity and Quantum Cosmology · Physics 2016-12-07 Claus Lämmerzahl , Christian J. Bordé

This paper provides a prospectus for a new way of thinking about the wavefunction of the universe: a $\Psi$-epistemic quantum cosmology. We present a proposal that, if successfully implemented, would resolve the cosmological measurement…

General Relativity and Quantum Cosmology · Physics 2017-11-15 Peter W. Evans , Sean Gryb , Karim P. Y. Thébault

The paper deals with cosmological solutions describing different phases of the Universe for the homogeneous and isotropic FLRW model of the Universe with torsion. Normally, torsion field is not suitable for maximally symmetric space time…

General Relativity and Quantum Cosmology · Physics 2020-10-30 Akash Bose , Subenoy Chakraborty

A multidimensional cosmology with FRW type metric having 4-dimensional space-time and $d$-dimensional Ricci-flat internal space is considered with a higher dimensional cosmological constant. The classical cosmology in commutative and…

General Relativity and Quantum Cosmology · Physics 2013-04-25 K. Zeynali , F. Darabi , H. Motavalli

This paper highlights cosmologically viable sine and cosine hyperbolic evolution functions in the framework of $f(Q,\mathcal{L}_m)$ gravity. The models have been tested to check the behavior of the equation of state (EoS) parameter under…

General Relativity and Quantum Cosmology · Physics 2026-02-02 V. A. Kshirsagar , S. A. Kadam , Vishwajeet S. Goswami

We introduce a time-delay function in bulk viscosity cosmology. Even for bulk viscosity functions where closed-form solutions are known, because of the time-delay term the exact solutions are lost. Therefore in order to study the…

General Relativity and Quantum Cosmology · Physics 2022-11-23 Andronikos Paliathanasis

We show that the late-time acceleration of the universe can be understood as a codimension-one bifurcation of the Friedmann dynamical system in the variables $(H,\Omega)$. At a critical value of the density-parameter combination, a…

General Relativity and Quantum Cosmology · Physics 2026-01-21 Spiros Cotsakis

We apply the gravity-thermodynamics conjecture, namely the first law of thermodynamics on the Universe horizon, but using the generalized Kaniadakis entropy instead of the standard Bekenstein-Hawking one. The former is a one-parameter…

General Relativity and Quantum Cosmology · Physics 2021-12-07 Andreas Lymperis , Spyros Basilakos , Emmanuel N. Saridakis

We consider a quantization of relativistic wave equations which allows to treat quantum fields together with interacting particles at a finite time. We discuss also a dissipative interaction with the environment. We introduce a stochastic…

High Energy Physics - Theory · Physics 2007-05-23 Z. Haba

We consider an autonomous differential system in $\mathbb{R}^n$ with a periodic orbit and we give a new method for computing the characteristic multipliers associated to it. Our method works when the periodic orbit is given by the…

Dynamical Systems · Mathematics 2007-05-23 Armengol Gasull , Hector Giacomini , Maite Grau

A cubic correction of $f(T)$ gravity, where $T$ is the teleparallel scalar torsion, is considered to describe gravity in spatially flat Friedmann-Robertson-Walker model. A scale factor permitting departure from inflation era has been…

General Physics · Physics 2015-11-06 G. G. L. Nashed , W. El Hanafy

In this paper, we have presented the cosmological model of the Universe that represents late time cosmic acceleration in torsion based gravitational theory, the $f(T)$ gravity. A well motivated parametrization for the Hubble parameter has…

General Relativity and Quantum Cosmology · Physics 2025-11-04 Suraj Kumar Behera , Pratik P. Ray , B. Mishra

The acceleration of the cosmic expansion revealed by supernova observations indicates that the present universe is dominated by repulsive dark energy. It is natural that the coupling between the dark energy and the attractive gravity has to…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-07 Ti-Pei Li , Mei Wu

The paper deals with cosmology in modified f(T) gravity theory. With some phenomenological choices for the function f(T) it is possible to have cosmological solutions describing different phases of the evolution of the Universe for the…

General Relativity and Quantum Cosmology · Physics 2020-11-03 Akash Bose , Subenoy Chakraborty

The present work deals with evolution of the fractal model of the Universe in the background of homogeneous and isotropic FLRW space--time geometry. The cosmic substrum is taken as perfect fluid with barotropic equation of state. A general…

General Physics · Physics 2018-11-27 Dipanjana Das , Sourav Dutta , Abdulla Al Mamon , Subenoy Chakraborty

This thesis explores the cosmological implications of modified gravity, focusing on nonmetricity-based $f(Q)$ gravity as an alternative to the $\Lambda$CDM model in explaining cosmic acceleration. Chapter I lays the theoretical groundwork…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Gaurav N. Gadbail

In this paper, we have explored the field equations of $f(T,B)$ gravity and determined the dynamical parameters with the hyperbolic function of Hubble parameter. The accelerating behavior has been observed and the behavior of equation of…

General Relativity and Quantum Cosmology · Physics 2022-07-22 S. A. Kadam , B. Mishra , S. K. Tripathy