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Related papers: Modified gravity for surveys

200 papers

We investigate the possibilities of reconstructing the cosmic equation of state (EoS) for high redshift. In order to obtain general results, we use two model-independent approaches. The first reconstructs the EoS using comoving distance and…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-28 A. M. Velasquez-Toribio , M. M. Machado , Julio C. Fabris

In this paper, we propose a new phenomenological two parameter parametrization of $q(z)$ to constrain barotropic dark energy models by considering a spatially flat FRW universe, neglecting the radiation component, and reconstructing the…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Jaime Roman-Garza , Tomas Verdugo , Juan Magana , Veronica Motta

Gravitational waves from core-collapse supernovae provide a unique probe of the equation of state (EOS) of high density matter. In this work, we focus on the bounce signal from numerical simulations of rotating supernovae and explore its…

The most popular Gogny parametrizations, namely D1S, D1N and D1M, describe accurately the ground-state properties of spherical and deformed finite nuclei all across the mass table obtained with Hartree--Fock--Bogoliubov (HFB) calculations.…

In this paper, we have investigated some exact cosmological models in Myrzakulov gravity using a flat Friedmann-Lematre-Robertson-Walker (FLRW) spacetime metric. We have considered the modified Lagrangian function as $F(R,T)=R+\lambda T$,…

General Relativity and Quantum Cosmology · Physics 2024-08-14 Dinesh Chandra Maurya , Ratbay Myrzakulov

We have conducted an extensive study using a diverse set of equations of state (EoSs) to uncover strong relationships between neutron star (NS) observables and the underlying EoS parameters using symbolic regression method. These EoS…

Nuclear Theory · Physics 2025-04-17 N. K. Patra , Tuhin Malik , Helena Pais , Kai Zhou , B. K. Agrawal , Constança Providência

This research investigates the impact of modified gravity on cosmic scales, focusing on $f(Q)$ cosmology. By applying energy conditions, the study reconstructs various $f(Q)$ models, considering an accelerating Universe, quintessence, and a…

General Relativity and Quantum Cosmology · Physics 2025-04-14 Irfan Mahmood , Hira Sohail , Allah Ditta , S. H. Shekh , Anil Kumar Yadav

In this study, we introduce a novel late-time effective dark energy model characterized by a quadratic equation of state (EoS) and rigorously examine its observational constraints. Initially, we delve into the background dynamics of this…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Hossein Moshafi , Alireza Talebian , Ebrahim Yusofi , Eleonora Di Valentino

A quasi-static approximation (QSA) for modified gravity can be applied in a number of ways. We consider three different analytical formulations based on applying this approximation to: (1) the field equations; (2) the equations for the two…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-03 Francesco Pace , Richard Battye , Emilio Bellini , Lucas Lombriser , Filippo Vernizzi , Boris Bolliet

For a new parameterization of the modified effective chiral model, developed primarily to regulate the density content of the symmetry energy and its higher order terms, equations of state (EoSs) for hyperon-rich matter ($H$) and delta…

High Energy Astrophysical Phenomena · Physics 2025-02-07 O. P. Jyothilakshmi , P. E. Sravan Krishnan , V. Sreekanth , Harsh Chandrakar , Tarun Kumar Jha

Equations of State (EoS) for fluids have been a staple of engineering design and practice for over a century. Available EoS are based on the fitting of a closed-form analytical expression to suitable experimental data. The underlying…

Computational Physics · Physics 2020-07-30 Kezheng Zhu , Erich A. Müller

Here in this work we propose a modified gravity with the action of $f(R) = \sqrt{R^2 - R_0^2}$ instead of Einstein-Hilbert action to describe the late time acceleration of the universe. We obtain the equation of the modified gravity both in…

Astrophysics · Physics 2008-11-26 Shant Baghram , Marzieh Farhang , Sohrab Rahvar

Neutron stars and their mergers provide the highest-density regime in which Einstein's equations in full (with a matter source) can be tested against modified theories of gravity. But doing so requires a priori knowledge of the Equation of…

High Energy Physics - Phenomenology · Physics 2022-02-09 Eva Lope-Oter , Felipe J. Llanes-Estrada

The present work is based on a parametric reconstruction of the deceleration parameter $q(z)$ in a model for the spatially flat FRW universe filled with dark energy and non-relativistic matter. In cosmology, the parametric reconstruction…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Abdulla Al Mamon , Sudipta Das

We describe and demonstrate the potential of a new and very efficient method for simulating certain classes of modified gravity theories, such as the widely studied $f(R)$ gravity models. High resolution simulations for such models are…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-14 Sownak Bose , Baojiu Li , Alexandre Barreira , Jian-hua He , Wojciech A. Hellwing , Kazuya Koyama , Claudio Llinares , Gong-Bo Zhao

We investigate the oscillating effective equation of state (EoS) of the universe around the phantom divide in the framework of $F(R)$ gravity. We illustrate the behavior of $F(R)$ with realizing multiple crossings of the phantom divide.

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Kazuharu Bamba , Chao-Qiang Geng

We develop a non-parametric method for inferring the universal neutron star (NS) equation of state (EOS) from gravitational wave (GW) observations. Many different possible realizations of the EOS are generated with a Gaussian process…

General Relativity and Quantum Cosmology · Physics 2019-05-08 Philippe Landry , Reed Essick

We discuss the constraints on the time-varying equation of state for dark energy and the curvature of the universe using observations of type Ia supernovae from Riess et al. and the most recent Supernova Legacy Survey (SNLS), the baryon…

Astrophysics · Physics 2009-11-13 Kazuhide Ichikawa , Tomo Takahashi

We show how observations of gravitational waves from binary neutron star (BNS) mergers over the next few years can be combined with insights from nuclear physics to obtain useful constraints on the equation of state (EoS) of dense matter,…

High Energy Astrophysical Phenomena · Physics 2019-10-23 Michael McNeil Forbes , Sukanta Bose , Sanjay Reddy , Dake Zhou , Arunava Mukherjee , Soumi De

We consider a modified gravity theory, f(R)=R-a/R^n+bR^m, in the metric formulation, which has been suggested to produce late time acceleration in the Universe, whilst satisfying local fifth-force constraints. We investigate the parameter…

High Energy Physics - Theory · Physics 2008-11-26 Anthony W. Brookfield , Carsten van de Bruck , Lisa M. H. Hall