The Frozen Star: Geometrical and Perturbative analysis

by Tom Shindelman

BGU

at Particles and Fields Seminar

Mon, 10 Feb 2025, 14:00
Sacta-Rashi Building for Physics (54), room 207

Abstract

One option for addressing the singularity issue still plaguing general relativity more than a 100 years since the discovery of the Schwarzschild black-hole solution, is to propose an alternative geometry with which to model the end-result of collapse. Such an object appears to outside observers to mimick all exterior properties of a Schwarzschild black hole, but remains well-behaved and paradox-free, and is thus termed a "black-hole mimicker". In this talk I will present an extensive investigation of one such BH-mimicker, called the Frozen Star.
A discussion of the interior spacetime will show how the Frozen Star prevents matter from penetrating inside, offering only trajectories on its surface and thus eliminating the threat of a singularity forming at its core. After laying the groundwork of constructing the metric, investigating its unique geometry and some illuminating coordinate choices, as well as the potential landscape and possible trajectories, a complete picture of the Frozen Star is now available to be further analyzed under perturbations.
In order to obtain non-trivial oscillation spectrum from the ultra stable Frozen Star, a "defrosted" version of it is constructed by introducing a small deviation from the original equation of state of the interior matter. The oscillation spectrum of non-radial modes is then obtained: First for the fluid alone in the Cowling approximation. Then, for both spacetime and fluid. I present a generic framework with which to obtain the full perturbation spectrum of any anisotropic star, as well as the particular spectrum of the Frozen Star.

Created on 03-02-2025 by Kats, Yevgeny (katsye)
Updaded on 03-02-2025 by Kats, Yevgeny (katsye)