Ayan Banerjee

Ayan Banerjee
University of KwaZulu-Natal | ukzn · School of Mathematics, Statistics and Computer Science

PhD

About

105
Publications
21,843
Reads
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1,737
Citations
Citations since 2017
89 Research Items
1646 Citations
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
Introduction
My research interests focus on studying the formation and evolution of compact astrophysical objects with analytical and numerical techniques. However, I enjoy all areas of theoretical and observational cosmology. My research has explored the possibility of finding black hole/ wormhole solutions, mainly focus on the mathematical structure of gravitational lensing and shadow.
Additional affiliations
November 2017 - present
University of KwaZulu-Natal
Position
  • PostDoc Position
Description
  • I am a theoretical Physicist as well as Mathematician. My research interest in General Relativity and Cosmology.
Education
November 2011 - February 2015
Jadavpur University
Field of study
  • Astrophysics and Cosmology
July 2006 - September 2008
Jadavpur University
Field of study
  • Applied Mathematics

Publications

Publications (105)
Preprint
Full-text available
Quark stars are terrestrial laboratories to study fundamental physics at ultrahigh densities and temperatures. In this work, we investigate the internal structure and the physical properties of quark stars (QSs) in the Rastall gravity. Rastall gravity is considered a non-conservative theory of gravity, which is an effective gravity theory at high e...
Article
We study the structure of quark stars (QSs) adopting homogeneously confined matter inside the star with a 3-flavor neutral charge and a fixed strange quark mass ms. We explore the internal structure, and the physical properties of specific classes of QSs in the recently proposed energy–momentum squared gravity (EMSG). Also, we obtain the mass–radiu...
Article
Exploiting the use of curvature coordinates (also called Schwarzschild coordinates), new classes of exact solutions are discovered. By prescribing the timelike potential two new solutions are found one of which displays all the necessary qualitative features demanded of closed compact astrophysical objects. Since the analysis reduces to a single fi...
Article
Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD) predicts the existence of non-nucleonic degrees of freedom at high densities in neutron-star matter, such as quar...
Preprint
Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD) predicts the existence of non-nucleonic degrees of freedom at high densities in neutron-star matter, such as quar...
Article
Full-text available
We investigate the possibility of existing a class of compact charged spheres made of a charged perfect fluid in the framework of Einstein–Gauss–Bonnet theory in five-dimensional spacetime (5 D EGB). In order to study spherically symmetric compact stars in EGB gravity, we prefer to apply a systematic and direct approach to decoupling gravitational...
Preprint
We study the structure of quark stars (QSs) adopting homogeneously confined matter inside the star with a 3-flavor neutral charge and a fixed strange quark mass $m_s$. We explore the internal structure, and the physical properties of specific classes of QSs in the recently proposed energy-momentum squared gravity (EMSG). Also, we obtain the mass-ra...
Article
We have investigated the possibility of existing a class of compact charged spheres made of a charged perfect fluid in the context of recently proposed 4D Einstein-Gauss–Bonnet (EGB) gravity theory. The main mechanism is to rescale the Gauss–Bonnet (GB) coupling constant α→α/(D−4) in D dimensions and redefining the 4D gravity in the limit D→4. In t...
Article
Recent instrumentation and computational advances have increased interest in determining the properties of nuclear matter under extreme conditions and the core of neutron stars (NSs) is an excellent test bed for nuclear astrophysical theories. Moreover, the detection of pulsars heavier than 2M⊙ have put strong constraints on the NS matter equation...
Article
Full-text available
In this work we study the properties of compact spheres made of a charged perfect fluid with a MIT bag model EoS for quark matter. Considering static spherically symmetric spacetime we derive the hydrostatic equilibrium equations in the recently formulated four dimensional Einstein–Gauss–Bonnet (4 D EGB) gravity theory. In this setting, the modifie...
Article
Full-text available
Gravitational-waves (GWs) data have widely been used for testing preferred modified gravity theories. In this paper, we investigate the possibility of testing them in the strong gravity regime by looking at the properties of compact objects in dense matter physics. In this direction modified gravity theories such as f ( R , T ) gravity can be teste...
Article
In astronomy, the study of compact stellar remnants — white dwarfs, neutron stars, black holes — has attracted much attention for addressing fundamental principles of physics under extreme conditions in the core of compact objects. In a recent argument, Maurya et al. [Eur. Phys. J. C 77, 45 (2017)] have proposed an exact solution depending on a spe...
Article
The observations of pulsars with masses close to [Formula: see text] have put strong constraints on the equation-of-state (EoS) of neutron-rich matter at supranuclear densities. Moreover, the exact internal composition of those objects is largely unknown to us. Aiming to reach the [Formula: see text] limit, here we investigate the impact of electri...
Article
Full-text available
Following the recent theory of f (Q) gravity, we continue to investigate the possible existence of wormhole geometries, where Q is the non-metricity scalar. Recently, the non-metricity scalar and the corresponding field equations have been studied for some spherically symmetric configurations in [ Phys. Lett. B 821, 136612 (2021) and Phys. Rev. D 1...
Preprint
Following the recent theory of $f(Q)$ gravity, we continue to investigate the possible existence of wormhole geometries, where $Q$ is the non-metricity scalar. Recently, the non-metricity scalar and the corresponding field equations have been studied for some spherically symmetric configurations in [ Phys. Lett. B 821, 136612 (2021) and Phys. Rev....
Preprint
Full-text available
The current trend concerning dense matter physics at sufficiently high densities and low temperatures is expected to behave as a degenerate Fermi gas of quarks forming Cooper pairs, namely a color superconductor, in the core of compact objects. In this context, we study the anisotropy of quark stars (QSs) assuming the internal composition to be com...
Article
Full-text available
An alternative gravity theory that has attracted considerable attention recently is the novel four-dimensional Einstein–Gauss–Bonnet (4EGB) gravity. This idea was proposed to bypass the Lovelock’s theorem and to permit nontrivial higher curvature effects on the four-dimensional local gravity. In this approach, the Gauss–Bonnet (GB) coupling constan...
Article
The current trend concerning dense matter physics at sufficiently high densities and low temperatures is expected to behave as a degenerate Fermi gas of quarks forming Cooper pairs, namely a color superconductor, in the core of compact objects. In this context, we study the anisotropy of quark stars (QSs) assuming the internal composition to be com...
Article
Full-text available
In this article, we develop a theoretical framework to study compact stars in Einstein gravity with the Gauss–Bonnet (GB) combination of quadratic curvature terms. We mainly analyzed the dependence of the physical properties of these compact stars on the Gauss–Bonnet coupling strength. This work is motivated by the relations that appear in the fram...
Preprint
In this work we study the properties of compact spheres made of a charged perfect fluid with a MIT bag model EoS for quark matter. Considering static spherically symmetric spacetime we derive the hydrostatic equilibrium equations in the recently formulated four dimensional Einstein-Gauss-Bonnet ($4D$ EGB) gravity theory. In this setting, the modifi...
Preprint
The observations of pulsars with masses close to 2$M_{\odot}$ have put strong constraints on the equation of state (EoS) of neutron-rich matter at supranuclear densities. Moreover, the exact internal composition of those objects is largely unknown to us. Aiming to reach the 2$M_{\odot}$ limit, here we investigate the impact of electric charge on pr...
Preprint
Full-text available
Within the framework of Einstein-Gauss-Bonnet theory in five-dimensional spacetime ($5D$ EGB), we derive the hydrostatic equilibrium equations and solve them numerically to obtain the neutron stars for both isotropic and anisotropic distribution of matter. The mass-radius relations are obtained for SLy equation of state, which describes both the so...
Article
Recent progress in the determination of both masses and radii of neutron stars have put strong constraints on the equation of state (EoS) above the nuclear saturation density. Within a confining quark matter model, we propose an anisotropic star consisting of a homogeneous and unpaired charge-neutral 3-flavor interacting quark matter with O(ms4) co...
Article
Full-text available
We investigate the properties of non-rotating, electrically charged strange quark stars in four-dimensional Einstein-Maxwell theory. For quark matter we adopt the well-motivated quantum chromodynamics (QCD) equation-of-state, while for the charge density we assume it is proportional to the mass density. The system of coupled structure equations are...
Preprint
We investigate the properties of non-rotating, electrically charged strange quark stars in four-dimensional Einstein-Maxwell theory. For quark matter we adopt the well-motivated quantum chromodynamics (QCD) equation-of-state, while for the charge density we assume it is proportional to the mass density. The system of coupled structure equations are...
Article
The observations of pulsars heavier than 2M⊙ have put strong constraints on the equation of state (EoS) above nuclear saturation density. For this reason, the internal structure of a neutron star which is strictly correlated with the EoS is an active area of investigation in theoretical astrophysics. Here, we investigate the possible sequels for th...
Article
Full-text available
In the present paper, we treat the problem of the existence of quark stars (QSs) for selected homogeneous and unpaired charge-neutral $3$-flavor interacting quark matter with $\mathcal{O}(m_s^4)$ corrections equations of state (EoS). Using the EoS combined with the Tolmann-Oppenheimer-Volkoff (TOV) structure equations, the properties of stars are e...
Preprint
In the present paper, we treat the problem of the existence of quark stars (QSs) for selected homogeneous and unpaired charge-neutral $3$-flavor interacting quark matter with $\mathcal{O}(m_s^4)$ corrections equations of state (EoS). Using the EoS combined with the Tolmann-Oppenheimer-Volkoff (TOV) structure equations, the properties of stars are e...
Article
Full-text available
It is known that the standard Schwarzschild interior metric is conformally flat and generates a constant density sphere in any spacetime dimension in Einstein and Einstein-Gauss-Bonnet (EGB) gravity. This motivates the questions: in EGB does the conformal flatness criterion yield the Schwarzschild metric? Does the assumption of constant density gen...
Article
Full-text available
The existence of strange matter in compact stars may pose striking sequels of the various physical phenomena. As an alternative to neutron stars, a new class of compact stars called strange stars should exist if the strange matter hypothesis is true. In the present article, we investigate the possible construction of the strange stars in quark matt...
Preprint
It is known that the standard Schwarzschild interior metric is conformally flat and generates a constant density sphere in any spacetime dimension in Einstein and Einstein--Gauss--Bonnet gravity. This motivates the questions: In EGB does the conformal flatness criterion yield the Schwarzschild metric? Does the assumption of constant density generat...
Article
Full-text available
Recently it has been proposed that the Gauss-Bonnet coupling parameter of Lovelock gravity may suitably be rescaled in order to admit physically viable models of celestial phenomena such that higher curvature effects are active in standard four dimensions as opposed to the usual higher dimensions. We investigate the consequences of this modificatio...
Article
Several attempts have been made in the past decades to search for the true ground state of the dense matter at sufficiently large densities and low temperatures via compact astrophysical objects. Focusing on strange stars, we derive the hydrostatic equilibrium assuming a maximally symmetric phase of homogeneous superconducting quark matter called t...
Article
Full-text available
The detection of gravitational waves (GWs) from the binary neutron star (BNS) has opened a new window on the gravitational wave astronomy. With current sensitivities, detectable signals coming from compact objects like neutron stars turn out to be a crucial ingredient for probing their structure, composition, and evolution. Moreover, the astronomic...
Preprint
Full-text available
Recently it has been proposed that the Gauss-Bonnet coupling parameter of Lovelock gravity may suitably be rescaled in order to admit physically viable models of celestial phenomena such that higher curvature effects are active in standard four dimensions as opposed to the usual higher dimensions. We investigate the consequences of this modificatio...
Preprint
Full-text available
To find more deliberate $f(R, T)$ astrophysical solutions, we proceed by studying wormhole geometries under the assumption of spherical symmetry and the existence of a conformal Killing symmetry to attain the more acceptable astrophysical results. To do this, we consider a more plausible and simple model $f(R,T)=R+2\chi T$, where $R$ is the Ricci s...
Article
Full-text available
Recent times witnessed a significant interest in regularizing, a \( D \rightarrow 4 \) limit, of EGB gravity initiated by Glavan and Lin [Phys. Rev. Lett. 124, 081301 (2020)] by re-scaling GB coupling constant as \(\alpha /(D-4)\) and taking limit \(D \rightarrow 4\), and in turn these regularized 4D gravities have nontrivial gravitational dynamics...
Preprint
Full-text available
The detection of gravitational waves (GWs) from the binary neutron star (BNS) has opened a new window on the gravitational wave astronomy. With current sensitivities, detectable signals coming from compact objects like neutron stars turn out to be a crucial ingredient for probing their structure, composition, and evolution. Moreover, the astronomic...
Preprint
Several attempts have been made in the past decades to search for the true ground state of the dense matter at sufficiently large densities and low temperatures via compact astrophysical objects. Focusing on strange stars, we derive the hydrostatic equilibrium assuming a maximally symmetric phase of homogeneous superconducting quark matter called t...
Preprint
The existence of strange matter in compact stars may pose striking sequels of the various physical phenomena. As an alternative to neutron stars, a new class of compact stars called strange stars should exist if the strange matter hypothesis is true. In the present article, we investigate the possible construction of the strange stars in quark matt...
Article
Full-text available
This work is devoted on the recently introduced Einstein-Gauss-Bonnet gravity in four dimensions. The theory can bypass the Lovelock's theorem and avoids Ostrogradsky instability. The integrated part of this theory is the GB term gives rise to a non-trivial contribution to the gravitational dynamics in the limit D->4. Our main interest is to explor...
Preprint
Full-text available
This work is devoted on the recently introduced Einstein-Gauss-Bonnet gravity in four dimensions. The theory can bypass the Lovelock's theorem and avoids Ostrogradsky instability. The integrated part of this theory is the GB term gives rise to a non-trivial contribution to the gravitational dynamics in the limit $D \to 4$. Our main interest is to e...
Preprint
Full-text available
Recently Glavan and Lin [Phys. Rev. Lett. 124, 081301 (2020)] formulated the Einstein-Gauss-Bonnet (EGB) gravity by re-scaling GB coupling constant as α/(D − 4) and taking limit D → 4 at the level of field equations. The GB contribution, in the resulting novel 4D EGB theory, makes a nontrivial contribution and the theory preserves the number of deg...
Preprint
Recently Glavan and Lin [Phys. Rev. Lett. 124, 081301 (2020)] formulated the Einstein-Gauss-Bonnet (EGB) gravity by re-scaling GB coupling constant as $\alpha/(D-4)$ and taking limit $D \to 4$ at the level of field equations. The GB contribution, in the resulting novel 4D EGB theory, makes a nontrivial contribution and the theory preserves the numb...
Article
Full-text available
In this paper, we consider wormhole geometries in the context of teleparallel equivalent of general relativity (TEGR) as well as f (T) gravity. The TEGR is an alternative geometrical formulation of Einstein's general relativity, where modified teleparallel gravity or f (T) gravity has been invoked as an alternative approach for explaining an accele...
Article
Full-text available
We consider f (R, T) theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the energy-momentum tensor, to study static spherically symmetric wormhole geometries sustained by matter sources with isotropic pressure. According to restrictions on the wormhole geometries, we caref...
Preprint
Full-text available
We consider $f(R, T)$ theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the energy-momentum tensor, to study static spherically symmetric wormhole geometries sustained by matter sources with isotropic pressure. According to restrictions on the wormhole geometries, we care...
Preprint
Full-text available
In this paper, we consider wormhole geometries in the context of teleparallel equivalent of general relativity (TEGR) as well as $f(T)$ gravity. The TEGR is an alternative geometrical formulation of Einstein's general relativity, where modified teleparallel gravity or $f(T)$ gravity has been invoked as an alternative approach for explaining an acce...
Article
This paper is devoted in the study of the hydrostatic equilibrium of stellar structure in the framework of modified f(R,T) gravity theory that allows the non-conservation of energy–momentum, with possible implications for several cosmological and astrophysical issues such as the late-time cosmic acceleration of the universe without appealing to exo...
Preprint
In this article we study the structure and stability of compact astrophysical objects which are ruled by the dark energy equation of state (EoS). The existence of dark energy is important for explaining the current accelerated expansion of the universe. Exact solutions to Einstein field equations (EFE) have been found by considering particularized...
Article
Full-text available
Investigations of shadows of astrophysical entities constitute a major source of insight into the evolution of compact objects. Such effects depend on the nature of the compact object and arise on account of the strong gravitational lensing that casts a shadow on the bright background. We consider the Kerr-like wormhole spacetime (Phys. Rev. D 97:0...
Preprint
Full-text available
We present a physically plausible solution representing Einstein's cluster mimicking the behaviors of compact star in the context of teleparallel equivalent of general relativity. The Teleparallel gravity (TEGR) is an alternative formulation of gravity which uses tetrads as the dynamical variables. We focus on two particularly interesting scenarios...
Article
Full-text available
We present a physically plausible solution representing Einstein's cluster mimicking the behaviors of compact star in the context of teleparallel equivalent of general relativity. The Teleparallel gravity (TEGR) is an alternative formulation of gravity which uses tetrads as the dynamical variables. We focus on two particularly interesting scenarios...
Preprint
This paper is devoted in the study of the hydrostatic equilibrium of stellar structure in the framework of modified $f(R, T)$ gravity theory that allows the non-conservation of energy-momentum, with possible implications for several cosmological and astrophysical issues such as the late-time cosmic acceleration of the universe without appealing to...
Article
Full-text available
Wormholes are one of the most interesting topological features in spacetime, offering a rat run between two vastly separated regions of the universe. In this paper, we study the deflection angle of light by wormholes, which are supported by electric charge, magnetic charge, and scalar fields in the weak field limit approximation. To this end, we ap...
Preprint
Braneworld models were firstly proposed as a great alternative for the hierarcy problem of particle physics, by allowing gravitons, differently from the other interacting bosons, to propagate through an extradimensional space named bulk. As time passed by the braneworld setup has also shown to be able to provide interesting results when applied to...
Article
In this article we present a class of relativistic solutions describing spherically symmetric and static anisotropic stars in hydrostatic equilibrium. For this purpose, we consider a particularized metric potential, namely, Buchdahl ansatz [Phys. Rev. D 116, 1027 (1959).] which encompasses almost all the known analytic solutions to the spherically...
Article
Full-text available
We study the gravitational deflection of relativistic massive particles by Janis-Newman-Winicour (JNW) spacetimes (also known as a rotating source with a surface-like naked singularity), and a rotating Kerr-like wormholes. Based on the recent article [K. Jusufi, Phys. Rev. D 98, 064017 (2018)], we extend some of these results by exploring the effec...
Article
Full-text available
We examine the effects of the Rastall parameter on the behaviour of spherically symmetric static distributions of perfect fluid matter. It was claimed by Visser [ arXiv:1711.11500 ] that the Rastall proposition is completely equivalent to the Einstein theory. While many authors demonstrated the objection, our intention is to analyze the properties...
Preprint
Full-text available
In this article we present a class of relativistic solutions describing spherically symmetric and static anisotropic stars in hydrostatic equilibrium. For this purpose, we consider a particularized metric potential, namely, Buchdahl ansatz [1] which encompasses almost all the known analytic solution to the spherically symmetric, static Einstein equ...
Article
The study of shadow is quite prominent nowadays because of the ongoing Event Horizon Telescope¹ observations. We construct the shadow images of charged wormholes in Einstein–Maxwell–dilaton (EMD) theory. The spacetime metric of the charged wormholes contains three charges: magnetic charge P, electric charge Q, and dilaton charge Σ. We evaluate the...
Article
Full-text available
The interest in studying relativistic compact objects play an important role in modern astrophysics with an aim to understand several astrophysical issues. It is therefore natural to ask for internal structure and physical properties of specific classes of compact star for astrophysical observable, and we obtain a class of new relativistic solution...
Article
Full-text available
Compelling alternatives to black holes, namely, gravitational vacuum star (gravastar) models: the multilayered structure compact objects, have been proposed to avoid a number of theoretical problems associated with event horizon and singularities. In this work, we construct spherically symmetric thin-shell charged gravastars model where the vacuum...
Preprint
We study the gravitational deflection of relativistic massive particles by Janis-Newman-Winicour (JNW) spacetimes (also known as a rotating source with a surface-like naked singularity), and a rotating Kerr-like wormholes. Based on the recent article [arXiv: 1806.01256], we extend some of these results by exploring the effects of naked singularity...
Preprint
Amongst a number of modified theories of gravity, the Rastall theory has been propounded to address some shortcomings of the standard theory of general relativity. Our purpose is to investigate this framework's capacity to analyse stellar structure in the context of elementary requirements for physical plausibility such as positive definite functio...
Preprint
Full-text available
The study of shadow continues to be a major source of insight into compact astrophysical objects. Depending on the nature of compact objects and due to the strong gravitational lensing effect that casts a shadow on the bright background. We consider the Kerr-like wormholes spacetime \cite{Bueno:2017hyj} which is a modification of Kerr black hole...
Preprint
The study of shadow is quite prominent nowadays because of the ongoing Event Horizon Telescope observations. We construct the shadow images of charged wormholes in Einstein-Maxwell-dilaton (EMD) theory. The spacetime metric of the charged wormholes contains three charges: magnetic charge $P$, electric charge $Q$, and dilaton charge $\Sigma$. We eva...
Article
We analyze the behavior of well-known stellar models within the context of f(R,T) modified theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar R and the trace of the energy-momentum tensor T, namely f(R,T)=R+2χT for some constant χ. The equation of pressure isotropy in this theory is identi...