The paper deals with an extensive study of null and timelike geodesics in the background of wormhole geometries. Starting with a spherically symmetric spacetime, null geodesics are analyzed for the Morris–Thorne wormhole (WH) and photon spheres are examined in WH geometries. Both bounded and unbounded orbits are discussed for timelike geodesics. A similar analysis has been done...
of the BH quantum level, generalizing the results in [13, 20–24]. Conflicts of Interest The authors declare that they have no conflicts of interest. Acknowledgments Subenoy Chakraborty acknowledges ... IUCAA, Pune, India, for their warm hospitality and research facilities at library. Subenoy Chakraborty also acknowledges the UGC-DRS Programme in the Department of Mathematics, Jadavpur University. Sourav
In the background of the homogeneous and isotropic FLRW model, the thermodynamics of the interacting DE fluid is investigated in the present work. By studying the thermodynamical parameters, namely the heat capacities and the compressibilities, both thermal and mechanical stability are discussed and the restrictions on the equation of state parameter of the dark fluid are analyzed.
The scalar–tensor f(R) theory of gravity is considered in the framework of a simple inhomogeneous space-time model. In this research we use the reconstruction technique to look for possible evolving wormhole solutions within viable f(R) gravity formalism. These f(R) models are then constrained so that they are consistent with existing experimental data. Energy conditions related...
The paper contains an extensive study of the unified first law (UFL) in the Friedmann–Robertson–Walker spacetime model. By projecting the UFL along the Kodama vector the second Friedmann equation can be obtained. Also studying the UFL on the event horizon it is found that the Clausius relation cannot be obtained from the UFL by projecting it along the tangent to the event horizon...
2Department of Mathematics, Jadavpur University, Kolkata 700 032, India Correspondence should be addressed to Subenoy Chakraborty; ni.ca.uvdj.htam@ytrobarkahcs Received 1 March 2017; Revised 29 March 2017 ... ; Accepted 4 April 2017; Published 14 June 2017 Academic Editor: Elias C. Vagenas Copyright © 2017 Sanjukta Chakraborty and Subenoy Chakraborty. This is an open access article distributed under the Creative
, West Bengal 700032, India Received 15 December 2014; Revised 20 March 2015; Accepted 26 March 2015 Academic Editor: Juan José Sanz-Cillero Copyright © 2015 Supriya Pan and Subenoy Chakraborty. This ... support through SRF scheme (File no. 09/096 (0749)/2012-EMR-I). Subenoy Chakraborty thanks UGC-DRS programme at the Department of Mathematics, Jadavpur University. Both the authors thank Inter University
Supriya Pan 0 Subenoy Chakraborty 0 0 Department of Mathematics, Jadavpur University , Kolkata 700 032 , India The present work deals with a spherically symmetric space-time which is asymptotically
Subenoy Chakraborty 0 0 Department of Mathematics, Jadavpur University , Kolkata, India The present work is a generalization of the recent work [arXiv.1206.1420] on the modified Hawking temperature
-BSR Programme of Jadavpur University for awarding Research Fellowship. Subenoy Chakraborty is thankful to UGC-DRS Programme, Department of Mathematics, Jadavpur University. References A. G. Riess, A
Programme of Jadavpur University for awarding Research Fellowship. Author Subenoy Chakraborty is thankful to UGC-DRS Programme in the Department of Mathematics, Jadavpur University. References S. W
The junction conditions between static and non-static space–times are studied for analysing gravitational collapse in the presence of a cosmological constant. We have discussed about the apparent horizon and their physical significance. We also show the effect of cosmological constant in the collapse and it has been shown that cosmological constant slows down the collapse of matter.