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BIMSA General Relativity Seminar
Invariant Definition of Photon Surfaces in General Relativity
Invariant Definition of Photon Surfaces in General Relativity
Organizers
Speaker
Time
Monday, September 2, 2024 3:30 PM - 4:30 PM
Venue
Online
Online
Zoom 559 700 6085
(BIMSA)
Abstract
In this talk, I will define the photon surface conditions using Cartan scalars within an invariant spin frame which offers a comprehensive description of the local spacetime geometry. By employing this approach, one can gain novel insights into the geometry and dynamics of photon surfaces, independent of the global spacetime structure. I will first discuss the photon surface conditions in a Petrov type-D spacetime manifold, and then I simplify those conditions assuming the existence of spherical symmetry. Finally, employing the simplified, spherically symmetric photon surface conditions, I will show the dynamics of photon surfaces in static spacetimes and collapsing Lemaitre-Tolman-Bondi (LTB) spacetimes and Vaidya spacetimes.
Speaker Intro
Dr. Dipanjan Dey completed his Ph.D. in Physics at the Indian Institute of Technology, Kanpur, India, in 2019, under the supervision of Professor Kaushik Bhattacharya. His doctoral research primarily focused on investigating the gravitational collapse of compact objects across various cosmological scenarios. Following his Ph.D., Dr. Dey joined the International Center for Cosmology at CHARUSAT, India, as a postdoctoral fellow under the guidance of Professor Pankaj S. Joshi. During this postdoctoral tenure, his research centered on the causal structure of singularities formed during the continual gravitational collapse of compact objects, with a particular emphasis on identifying possible physical signatures of non-spacelike singularities. In March 2020, Dr. Dey was appointed as an assistant professor at the International Center for Cosmology, CHARUSAT, India. Throughout his time there, he made significant contributions to academia through research, teaching, and administrative responsibilities. In October 2022, he joined Dalhousie University as an AARMS postdoctoral fellow under the supervision of Professor Alan A. Coley. At Dalhousie, Dr. Dey's work involved studying the causal structure of singularities in a coordinate-independent manner, utilizing the spinor structure of the spacetime manifold in the context of collapsing compact objects.