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相关论文: Anisotropic Compact stars with variable cosmologic…

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In present paper a new compact star model in f(R,T) gravity is obtained where R and T denote the Ricci scalar and the trace of energy-momentum tensor $T_{\mu \nu}$ respectively. To develop the model we consider the spherically symmetric…

广义相对论与量子宇宙学 · 物理学 2021-06-01 Piyali Bhar

We present a model for compact stars in the low mass X-ray binaries(LMXBs) and X-ray pulsars using a metric given by John J. Matese and Patrick G. Whitman \citep{Matese and Whitman1980}. Here the field equations are reduced to a system of…

广义相对论与量子宇宙学 · 物理学 2014-10-02 Mehedi Kalam , Sk. Monowar Hossein , Sajahan Molla

We present a systematic investigation of the cosmological constant effects in compact stars interiors in the framework of Einstein's gravity. Consideration of a cosmological constant $\Lambda$ in compact stars is motivated by the mechanism…

高能天体物理现象 · 物理学 2019-02-05 Noshad Khosravi Largani , David E. Alvarez-Castillo

We investigate realistic models of compact objects, focusing on neutron and strange stars, composed by dense matter and dark energy in the form of a simple fluid or scalar field interacting with matter. For the dark energy component, we use…

广义相对论与量子宇宙学 · 物理学 2023-08-01 Artyom V. Astashenok , Sergey D. Odintsov , Vasilis K. Oikonomou

We extract new classes of anisotropic solutions in the framework of mimetic gravity, by applying the Tolman-Finch-Skea metric and a specific anisotropy not directly depending on it, and by matching smoothly the interior anisotropic solution…

广义相对论与量子宇宙学 · 物理学 2023-04-19 G. G. L. Nashed , Emmanuel N. Saridakis

We investigate anisotropic compact stars comprising two non-interacting fluids: quark matter and condensed dark matter. Using the MIT Bag model equation of state for quark matter and Bose-Einstein Condensate equation of state for dark…

广义相对论与量子宇宙学 · 物理学 2025-05-28 G. Panotopoulos , A. Rincón , I. Lopes

This study deals with the formation and evolution of a strange star in the Krori Barua Rainbow spacetime from collapsing charged stringy quark matter. The dynamical variables are explored from the field equations, taking into account the…

广义相对论与量子宇宙学 · 物理学 2024-01-26 Wasib Ali , Umber Sheikh

In this paper, we develop a new relativistic compact stellar model for a spherically symmetric anisotropic matter distribution. The model has been obtained through generating a new class of solutions by invoking the Tolman {\em ansatz} for…

广义相对论与量子宇宙学 · 物理学 2020-11-25 Piyali Bhar , Shyam Das , Bikram Keshari Parida

The conceptual difficulties associated with a cosmological constant have led to the investigation of alternative models in which the equation of state parameter, $w=p/\rho$, of the dark energy evolves with time. We show that combining the…

天体物理学 · 物理学 2007-05-23 H. K. Jassal , J. S. Bagla , T. Padmanabhan

We derive the equation for pressure within a neutron star, taking into account a non-zero cosmological constant ($\Lambda$). We then examine the stability of the neutron star's equilibrium state in the presence of cosmological constant. Our…

广义相对论与量子宇宙学 · 物理学 2025-04-22 Naveen K. Singh , Gopal Kashyap

This study simulates the characteristics of spherically symmetric, anisotropic compact stellar bodies with electrical charge within the framework of the $f(Q)$ theory of gravity. Employing the Krori-Barua metric ansatz (K.D. Krori, J.…

广义相对论与量子宇宙学 · 物理学 2024-11-05 Debadri Bhattacharjee , Pradip Kumar Chattopadhyay

We numerically construct compact stars in the scalar-tensor theory of gravity with non-minimal derivative coupling of a scalar field to the curvature and nonzero cosmological constant. There are two free parameters in this model of gravity:…

广义相对论与量子宇宙学 · 物理学 2025-04-08 P. E. Kashargin , A. A. Lebedev , S. V. Sushkov

We propose and investigate a class of dynamical dark energy models in which the cosmological constant evolves from negative values in the early Universe to a positive value at low redshifts. This framework includes a generalised ladder-step…

宇宙学与河外天体物理 · 物理学 2026-02-20 Mariam Bouhmadi-López , Beñat Ibarra-Uriondo

This paper investigates a spherically symmetric compact relativistic body with isotropic pressure profiles within the framework of general relativity. In order to solve the Einstein's field equations, we have considered the Vaidya-Tikekar…

星系天体物理 · 物理学 2021-11-29 Jitendra Kumar , Puja Bharti

Interested in the collapse of a radiating star, we study the temporal evolution of a fluid with heat flux and bulk viscosity, including anisotropic pressure. As a starting point, we adopt an initial configuration that satisfies the…

广义相对论与量子宇宙学 · 物理学 2018-11-27 L. S. M. Veneroni , M. F. A. da Silva

The main purpose of this paper is to obtain physically stable stellar models coupled with anisotropic matter distribution in the context of $f(\mathcal{R},\mathrm{T}^{2})$ theory. For this, we consider a static spherical geometry and…

广义相对论与量子宇宙学 · 物理学 2024-06-06 Tayyab Naseer , M. Sharif , Sana Manzoor , Arooj Fatima

We obtain a class of anisotropic spherically symmetric relativistic solutions of compact objects in hydrostatic equilibrium in the $f(R,T) =R+2\chi T$ modified gravity, where $R$ is the Ricci scalar, $T$ is the trace of the energy momentum…

综合物理 · 物理学 2020-09-18 S. Dey , A. Chanda , B. C. Paul

We investigate whether compact stars having Tolman-like interior geometry admit conformal symmetry. Taking anisotropic pressure along the two principal directions within the compact object, we obtain physically relevant quantities such as…

广义相对论与量子宇宙学 · 物理学 2016-07-25 Farook Rahaman , Sunil D. Maharaj , Iftikar Hossain Sardar , Koushik Chakraborty

In this work we obtain an anisotropic neutron star solution by gravitational decoupling starting from a perfect fluid configuration which has been used to model the compact object PSR J0348+0432. Additionally, we consider the same solution…

广义相对论与量子宇宙学 · 物理学 2019-10-14 Victor Torres , Ernesto Contreras

The gravitational-wave signal GW190814 involves a compact object with mass $(2.50-2.67){\rm M}_\odot$ within the so-called low mass gap. As yet, a general consensus on its nature, being a black hole, a neutron star or an exotic star, has…

广义相对论与量子宇宙学 · 物理学 2021-02-02 Zacharias Roupas