98 citations · 366 across the 19 of their papers we have counts for
19 papers
Optical appearance of regularized compact objects without an exterior photon sphere
Ashok B. Joshi, Vishva Patel, Parth C. Varasani
Recent observations by the Event Horizon Telescope (EHT) indicate that the shadow of the compact object at our Galaxy's center (Sgr A*) closely resembles that of a Schwarzschild bl…
Thermodynamic Phase Transitions and Quantum Entropy Corrections in the Simpson-Visser Regular Black Hole
Vinayak Joshi, Ashok B. Joshi
Regular black holes offer a compelling framework to explore the consequences of resolving the central singularity of standard black holes. Using the Simpson-Visser ``black-bounce"…
Tidal disruption of a neutron star near naked singularity
Ashok B. Joshi, Pankaj S. Joshi, Sudip Bhattacharyya
We investigate the tidal disruption of a neutron star (NS) near a black hole (BH), and for the first time, to the best of our knowledge, near a naked singularity (NaS). For a BH wi…
Tidal forces in collapsing compact objects
Ashok B. Joshi, Dipanjan Dey, Pankaj S. Joshi +1
In this work, we investigate tidal forces in the Lemaitre-Tolman-Bondi (LTB) metric, focusing on both hidden and locally visible singularities. We discuss the strength of these sin…
Spacetime singularities and caustic of outgoing null hypersurfaces
Ashok B. Joshi
In this paper, we investigate the caustic point developed by outgoing null hypersurfaces and the behavior of null curves. We analyze three cases: Future, past, and zero caustic poi…
Particle motion and tidal force in a non-vacuum-charged naked singularity
Divyesh P. Viththani, Ashok B. Joshi, Tapobroto Bhanja +1
In this article, we investigate the gravitational field of a charged, non-vacuum, non-rotating, spherically symmetric body of mass assuming a static solution to the Einstein-Ma…
Future-null singularity due to gravitational collapse
Ashok B. Joshi, Karim Mosani, Pankaj S. Joshi
In the case of unhindered gravitational collapse of matter cloud governed by the Lemaitre-Tolman-Bondi (LTB) spacetime, the end-state singularity is either locally visible, globall…
Observational aspects of a class of Dark matter spacetimes
Ashok B. Joshi, Divya Tahelyani, Dipanjan Dey +1
Various astrophysical and cosmological observations today serve as an indirect evidence of the existence of dark matter in the universe. In the present work, we propose a class of…
Relativistic orbits of S2 star in the presence of scalar field
Parth Bambhaniya, Ashok B. Joshi, Dipanjan Dey +4
The general theory of relativity predicts the relativistic effect in the orbital motions of S-stars which are orbiting around our Milky-way galactic center. The post-Newtonian or h…
Light trajectory and shadow shape in the rotating naked singularity
Vishva Patel, Divya Tahelyani, Ashok B. Joshi +2
In this paper, we investigate the light trajectories and shadow properties in the rotating version of null naked singularity (NNS) spacetime which is derived using the Newman- Jani…
Comparing thin accretion disk properties of naked singularities and black holes
Divya Tahelyani, Ashok B. Joshi, Dipanjan Dey +1
In the present paper, we study the thermal properties of the geometrically thin accretion disks surrounding the null naked singularity (NNS) and the first type of Joshi-Malafarina-…
Lense-Thirring effect and precession of timelike geodesics in slowly rotating black hole and naked singularity spacetimes
Parth Bambhaniya, Jay S. Verma, Dipanjan Dey +2
In this paper, we investigate the properties of the Lense-Thirring precession frequency and periastron precession of the relativistic bound orbits in slowly rotating naked singular…
Comparing Shadows of Blackhole and Naked Singularity
Kanwar Preet Kaur, Pankaj S. Joshi, Dipanjan Dey +2
It is now theoretically well established that not only a black hole can cast shadow, but other compact objects such as naked singularities, gravastar or boson stars can also cast s…
Towards an observational test of black hole versus naked singularity at the galactic center
Dipanjan Dey, Pankaj S. Joshi, Ashok Joshi +1
While the event horizon of a black hole could cast a shadow that was observed recently, a central singularity without horizon could also give rise to such a feature. This leaves us…
Shadows and negative precession in non-Kerr spacetime
Parth Bambhaniya, Dipanjan Dey, Ashok B. Joshi +3
It is now known that the shadow is not only the property of a black hole, it can also be cast by other compact objects like naked singularities. However, there exist some novel fea…
Precession of timelike bound orbits in Kerr spacetime
Parth Bambhaniya, Divyesh N. Solanki, Dipanjan Dey +3
Astrometric observations of S-stars provide a unique opportunity to probe the nature of Sagittarius-A* (Sgr-A*). In view of this, it has become important to understand the nature a…
Shadow of a Naked Singularity without Photon Sphere
Ashok B. Joshi, Dipanjan Dey, Pankaj S. Joshi +1
It is generally believed that the shadows of either a black hole or naked singularity arise due to photon spheres developing in these spacetimes. Here we propose a new spherically…
Timelike Geodesics in Naked Singularity and Black Hole Spacetimes II
Ashok B. Joshi, Parth Bambhaniya, Dipanjan Dey +1
We derive here the orbit equations of particles in naked singularity spacetimes, namely the Bertrand (BST) and Janis-Newman-Winicour (JNW) geometries, and for the Schwarzschild bla…
Timelike geodesics in Naked Singularity and Black Hole Spacetimes
Parth Bambhaniya, Ashok B. Joshi, Dipanjan Dey +1
In this paper, we derive the solutions of orbit equations for a class of naked singularity spacetimes, and compare these with timelike orbits, that is, particle trajectories in the…