Speaker: Dr. István Rácz
Title: Spacetime Singularities and Curvature Blow-ups (related to his application for the title of ‘Research Professor’)
Date: 20 March 2023, 14:00
Place: Building 2, Media room
https://wigner-hu.zoom.us/j/82025007930?pwd=MGEwSjNVY2xoZ0tkb2xJYm03clV…
Meeting ID: 820 2500 7930
Passcode: 260343
Abstract
The “singularity theorems” of Penrose, Hawking, and Geroch predict only the existence of incomplete inextendible causal geodesics in a wide range of physically adequate spacetimes modeling the gravitational collapse of stars and the expanding universe. In contrast, on physical grounds, singularities are expected to be associated with the blow-up of some physical quantities. The aim of this seminar is to give a brief overview of the basic concepts related to our current understanding of spacetime singularities. Special attention will be given to some aspects of the initial value formulation of general relativity, the cosmic censor hypotheses proposed by Penrose, and also to results on spacetime extensions. These preparations will be used to outline an argument that could provide important insights into the generic properties of spacetime singularities. In particular, it will be argued that if a suitable low regular form of the strong cosmic censor hypothesis holds, then a parallelly propagated blow-up of either the tidal force or the frame-drag part of the curvature must occur in “generic” timelike geodesically incomplete maximal Cauchy developments.
References:
* Rácz, I. (1993): Spacetime extensions I., Journal of Mathematical Physics 34, 2448-2464
* Rácz, I. (2010): Spacetime extensions II, Classical and Quantum Gravity, 27, 155007,
In 2011 the Editorial Board of Classical and Quantum Gravity selected this paper as one of the Highlights of 2010.
* Rácz, I. (2023): Spacetime singularities and curvature blow-ups, General Relativity and Gravitation 55, Article number: 3
