Light trajectories and thermal shadows casted by black holes in a cavity
Abstract We explore the shadows and the photon rings casted by black holes in cavity. Placing the observer inside such an isothermal background, we examine the influence of the cavity temperature T cav and the charge Q on the involved optical features. After studying the effect of the horizon radius...
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Published in | Journal of cosmology and astroparticle physics Vol. 2023; no. 11; pp. 94 - 111 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Bristol
IOP Publishing
01.11.2023
|
Subjects | |
Online Access | Get full text |
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Summary: | Abstract
We explore the shadows and the photon rings casted by black holes in cavity. Placing the
observer inside such an isothermal background, we examine the influence of the cavity
temperature
T
cav
and the charge
Q
on the involved optical features. After
studying the effect of the horizon radius by varying
Q
, we investigate the thermal
behaviors of the black hole shadows in a cavity. For fixed charge values, we find that the
shadow radius
r
s
increases by decreasing
T
cav
. Varying such a temperature, we
discuss the associated energy emission rate. After that, we show that the curves in the
r
s
-
T
cav
plane share similarities with the
G
-
T
curves of the Anti de Sitter black
holes. Then, we study the trajectories of the light rays casted by black holes in a cavity.
We further observe that the light trajectory behaviors are different than the ones of the
non rotating black holes due to the cavity effect. Finally, we provide an evidence for the
existence of an universal ratio defined in terms of the photon sphere radius and the impact
parameter. Concretely, we obtain an optical ratio
b
sp
/
r
sp
∼√(3). |
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ISSN: | 1475-7516 1475-7516 |
DOI: | 10.1088/1475-7516/2023/11/094 |