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It is shown that cosmological equations for homogeneous isotropic models deduced in the framework of the Poincar\'e gauge theory of gravity by certain restrictions on indefinite parameters of gravitational Lagrangian take at asymptotics the…

General Relativity and Quantum Cosmology · Physics 2009-09-29 A. V. Minkevich

There are, at present, several gravitational and cosmological anomalies; the dark energy problem, the lambda problem, accelerating cosmological expansion, the anomalous Pioneer spacecraft acceleration, a spin-up of the Earth and an apparent…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. A. Barber

I propose a unified model of particle physic and cosmology based on both a new extension of the standard particle model and the fundamental principle of the standard cosmology. Beyond the SM, I introduce several species of dark fields with…

General Physics · Physics 2025-05-13 Wei-Min Yang

In this talk I present a new model of a unified dark sector, where late-time cosmic acceleration emerges from the dark matter (DM) superfluid framework. We will start by reviewing the dark matter superfluid model and show how it describes…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-19 Elisa G. M. Ferreira

The unexpectedly large abundance of UV-bright galaxies at $z>10$ discovered by the James Webb Space Telescope poses a significant challenge to the standard $\Lambda$CDM cosmology. This work tests whether modifying the cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-04 Anirban Chakraborty , Tirthankar Roy Choudhury , Anjan Ananda Sen , Purba Mukherjee

We present a modified cosmological scenario that arises from the application of non-extensive thermodynamics with varying exponent. We extract the modified Friedmann equations, which contain new terms quantified by the non-extensive…

General Relativity and Quantum Cosmology · Physics 2019-03-27 Shin'ichi Nojiri , Sergei D. Odintsov , Emmanuel N. Saridakis

Expansion dynamics of the Universe is one of the important subjects in modern cosmology. The dark energy equation of state determines this dynamics so that the Universe is in an accelerating phase. However, the dark matter can also affect…

General Relativity and Quantum Cosmology · Physics 2025-10-08 Zeinab Rezaei

Recent astronomical observations of SNIa, CMB, as well as BAO in the Sloan Digital Sky Survey, suggest that the current Universe has entered a stage of an accelerated expansion with the transition redshift at $z \simeq 0.5$. While the…

Astrophysics · Physics 2010-11-11 Aleksandra Kurek , Marek Szydlowski

A formalism for the appearance of dark energy in the matter dominated era, leading to a persistent de Sitter expansion at the late time is proposed. Our framework is a hybrid quintessence model with a non-minimal coupling to the Ricci…

General Relativity and Quantum Cosmology · Physics 2018-11-29 H. Mohseni Sadjadi

Dark energy is a fundamental constituent of our universe, its status in the cosmological field equation should be equivalent to that of gravity. Here we construct a dark energy and matter gravity coupling (DEMC) model of cosmology in a way…

General Physics · Physics 2015-01-14 Ti-Pei Li

In `entropic cosmology', instead of a cosmological constant $\Lambda$, an extra driving term is added to the Friedmann equation and the acceleration equation, taking into account the entropy and the temperature on the horizon of the…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-14 Nobuyoshi Komatsu , Shigeo Kimura

We model the large scale late time universe as a Lambda-CDM cosmology driven by cosmological constant and perfect dust fluid. Our aim is to find new solutions in the matter and Lambda epoch consistent with inflationary initial conditions,…

High Energy Physics - Theory · Physics 2013-05-29 Toby Wiseman , Benjamin Withers

Here, cosmology of the late and future universe is obtained from $f(R)$-gravity with non-linear curvature terms $R^2$ and $R^3$ ($R$ being the Ricci scalar curvature). It is different from $f(R)$-dark enrgy models, where non-linear…

General Relativity and Quantum Cosmology · Physics 2009-09-17 S. K. Srivastava

We construct gravitational modifications that go beyond Horndeski, namely theories with extended nonminimal derivative couplings, in which the coefficient functions depend not only on the scalar field but also on its kinetic energy. Such…

General Relativity and Quantum Cosmology · Physics 2017-03-01 Tiberiu Harko , Francisco S. N. Lobo , Emmanuel N. Saridakis , Minas Tsoukalas

By means of the present geometrical and dynamical observational data, it is very hard to establish, from a statistical perspective, a clear preference among the vast majority of the proposed models for the dynamical dark energy and/or…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Tomasz Denkiewicz , Vincenzo Salzano

The late time acceleration of the Universe has challenged contemporary cosmology since its discovery. General Relativity explains this phenomenon by introducing the cosmological constant, named the standard cosmological model…

General Relativity and Quantum Cosmology · Physics 2024-01-02 Simran Arora

The matter creation cosmology is revisited, including the evolution of baryons and dark matter particles. The creation process affects only dark matter and not baryons. The dynamics of the $\Lambda$CDM model can be reproduced only if two…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-08 J. C. Fabris , J. A. de Freitas Pacheco , O. F. Piattella

A dynamical resolution to the cosmological constant fine-tuning problem has been previously put forward, based on a scalar-tensor gravitational theory possessing de Sitter attractor solutions characterized by a small Hubble expansion rate,…

General Relativity and Quantum Cosmology · Physics 2021-08-19 Oleg Evnin , Victor Massart , Kevin Nguyen

Modified Dark Matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics, that naturally accounts for the universal acceleration constant observed in galactic rotation curve data; a critical…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-03 Douglas Edmonds , Duncan Farrah , Djordje Minic , Y. Jack Ng , Tatsu Takeuchi

We present a physically motivated dark-energy (DE) model rooted in the topological structure of the Quantum ChromoDynamic (QCD) vacuum. In this framework, DE arises from the difference between the vacuum energy of an expanding FRW universe…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-03 Ludovic Van Waerbeke , Ariel Zhitnitsky
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