Saved in:
Bibliographic Details
Main Author: Minwalla, Spandan
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2310.16643
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929594085408768
author Minwalla, Spandan
author_facet Minwalla, Spandan
contents We perform a matched asymptotic expansion to find an analytic formula for the trajectory of a light ray in a Schwarzschild metric, in a power series expansion in the deviation of the impact parameter from its critical value. We present results valid to second sub leading order in this expansion. We use these results to find an analytic expansion for the angular location of the $n^{th}$ Einstein Ring (at large $n$) resulting from a star that lies directly behind a black hole but not necessarily far from it. The small parameter for this expansion is $e^{-π(2n+1)}$: our formulae are accurate to third order in this parameter.
format Preprint
id arxiv_https___arxiv_org_abs_2310_16643
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Angular Location of the $n^{th}$ Einstein Ring at large $n$
Minwalla, Spandan
General Relativity and Quantum Cosmology
Astrophysics of Galaxies
High Energy Astrophysical Phenomena
We perform a matched asymptotic expansion to find an analytic formula for the trajectory of a light ray in a Schwarzschild metric, in a power series expansion in the deviation of the impact parameter from its critical value. We present results valid to second sub leading order in this expansion. We use these results to find an analytic expansion for the angular location of the $n^{th}$ Einstein Ring (at large $n$) resulting from a star that lies directly behind a black hole but not necessarily far from it. The small parameter for this expansion is $e^{-π(2n+1)}$: our formulae are accurate to third order in this parameter.
title Angular Location of the $n^{th}$ Einstein Ring at large $n$
topic General Relativity and Quantum Cosmology
Astrophysics of Galaxies
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2310.16643