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Related papers: Noether's stars in $f(\cal {R})$ gravity

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This paper investigates the geometry of static traversable wormhole through Noether symmetry approach in $f(R)$ gravity. We take perfect fluid distribution and formulate symmetry generators with associated conserved quantities corresponding…

General Relativity and Quantum Cosmology · Physics 2018-04-04 M. Sharif , Iqra Nawazish

In Palatini $f(R)$ gravity, the parameters of the Schwarzschild - de Sitter solution as well as the whole interior solutions of compact objects are expected to change when compared to general relativity. We solve the Palatini field…

General Relativity and Quantum Cosmology · Physics 2009-12-07 Vappu Reijonen

Some analytical spherical-symmetric equilibrium solutions are cosidered in the Newtonian theory of gravitation with deviations from 1/r law. Stability of star against a first-order phase-transition is shown to be particularly influenced by…

Astrophysics · Physics 2007-05-23 Zakir F. Seidov

We present a brief review of general results about non-rotating neutron stars in simple R-square gravity and its extension with a scalar axion field. Modified Einstein equations are presented for metrics in isotropical coordinates. The…

General Relativity and Quantum Cosmology · Physics 2020-07-08 Artyom V. Astashenok , Sergei D. Odintsov

We propose an action-based $ f(R) $ modification of Einstein's gravity which admits of a modified Schwarzschild-deSitter metric. In the weak field limit this amounts to adding a small logarithmic correction to the newtonian potential. A…

Astrophysics · Physics 2009-11-11 Y. Sobouti

We investigate the equilibrium and radial stability of spherically symmetric relativistic stars, considering a polytropic equation of state (EoS), within the framework of $f(R,T)$ gravity with a conservative energy-momentum tensor. Both…

General Relativity and Quantum Cosmology · Physics 2021-08-26 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis , José D. V. Arbañil

Within the framework of $f(R)=R+\alpha R^2$ gravity, we study realistic models of neutron stars, using equations of state compatible with the LIGO constraints. i.e. APR4, MPA1, SLy, and WW1. By numerically solving modified…

High Energy Astrophysical Phenomena · Physics 2020-02-26 Pasquale Feola , Xisco Jimenez Forteza , Salvatore Capozziello , Roberto Cianci , Stefano Vignolo

We solve the Schr\"odinger-Newton problem of Newtonian gravity coupled to a nonrelativistic scalar particle for solutions with axial symmetry. The gravitational potential is driven by a mass density assumed to be proportional to the…

High Energy Physics - Theory · Physics 2024-12-30 A. Flores , C. Stegner , S. S. Chabysheva , J. R. Hiller

Aether Scalar-Tensor theory is a modification of general relativity proposed to explain galactic and cosmological mass discrepancies conventionally attributed to dark matter.~The theory is able to fit the cosmic microwave background and the…

General Relativity and Quantum Cosmology · Physics 2025-02-20 Christopher Reyes , Jeremy Sakstein

This paper deals with the study of Bianchi type-I universe in the context of Nash gravity by using the Noether symmetry approach. We shortly revisit the Nash theory of gravity. We make a short recap of the Noether symmetry approach and…

General Physics · Physics 2019-03-12 Phongpichit Channuie , Davood Momeni , Mudhahir Al Ajmi

Adopting Noether point symmetries, we classify and integrate dynamical systems coming from Horndeski cosmologies. The method is particularly effective both to select the form of Horndeski models and to derive exact cosmological solutions.…

General Relativity and Quantum Cosmology · Physics 2018-07-04 Salvatore Capozziello , Konstantinos F. Dialektopoulos , Sergey V. Sushkov

In this work we investigate the structure of neutron stars in modified f(T) gravity models. We find that, unlike the f(R) models, the equations of motion put a rather strict constraint on the possible f(T) functions. Specifically, after…

General Relativity and Quantum Cosmology · Physics 2015-09-11 Cemsinan Deliduman , Baris Yapiskan

The form of the coupling of the scalar field with gravity and the potential have been found by applying Noether theorem to two dimensional minisuperspaces in induced gravity model. It has been observed that though the forms thus obtained…

General Relativity and Quantum Cosmology · Physics 2008-11-26 A. K. Sanyal , B. Modak

This paper investigates the structure and properties of neutron stars in four-dimensional non-polynomial gravities. Solving the modified Tolman-Oppenheimer-Volkoff equations for three different equations of state (BSk19, SLy4, AP4), we…

General Relativity and Quantum Cosmology · Physics 2025-12-30 Chen Tan , Yong-Qiang Wang

We formulate the generalized Tolman-Oppenheimer-Volkoff equations for the $f(\hat{R})$ Palatini gravity in the case of static and spherical symmetric geometry. We also show that a neutron star is a stable system independently of the form of…

General Relativity and Quantum Cosmology · Physics 2018-05-31 Aneta Wojnar

In this paper, we consider a spherical symmetric metric to extract the hydrostatic equilibrium equation of stars in $(3+1)-$dimensional gravity's rainbow in the presence of cosmological constant. Then, we generalize the hydrostatic…

High Energy Physics - Theory · Physics 2016-09-19 S. H. Hendi , G. H. Bordbar , B. Eslam Panah , S. Panahiyan

The torsion models have stood out among the proposals for an alternative description of gravity. The simplest of them, the Teleparallel theory, is equivalent to General Relativity and there are many studies that seek to study its extension…

General Relativity and Quantum Cosmology · Physics 2022-12-09 H. G. M. Fortes , J. C. N. de Araujo

The paper deals with phantom scalar field cosmology in Einstein gravity. At first using Lie symmetry, the coupling function to the kinetic term and the potential function of the scalar field and the equation of state parameter of the matter…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Sourav Dutta , Subenoy Chakraborty

In this work we investigate neutron stars (NS) in $f(\mathtt{R,L_m})$ theory of gravity for the case $f(\mathtt{R,L_m}) = \mathtt{R} + \mathtt{L_m} + \sigma\mathtt{R}\mathtt{L_m}$, where $\mathtt{R}$ is the Ricci scalar and $\mathtt{L_m}$…

General Relativity and Quantum Cosmology · Physics 2021-11-19 R. V. Lobato , G. A. Carvalho , C. A. Bertulani

The masses and radii of neutron stars are discussed in general relativity and scalar-tensor theory of gravity and the differences are compared with the current uncertainties stemming from the nuclear equation of state in the relativistic…

General Relativity and Quantum Cosmology · Physics 2019-07-16 F. J. Fattoyev