Speaker
Description
The Aether-Scalar-Tensor (AeST) theory is an extension of General
Relativity (GR) which allows for Modified Newtonian Dynamics (MOND) in
its static weak-field limit and a LCDM-like cosmological limit.
MOND successfully describes the behaviour of galaxies without the need
for dark matter. This is best summarised by the Radial Acceleration
Relation (RAR), which directly relates the observed gravitational
acceleration to the acceleration expected from the gravity of the
baryons alone. However, it is generally accepted that MOND fails to
account for the state of galaxy clusters, apparently needing missing
matter to fit the observations.
We consider static spherically symmetric weak-field solutions of AeST
and study the hydrostatic isothermal gaseous sphere as a simplified
model of a galaxy cluster in AeST. We construct the RAR of AeST for
isothermal spheres and find that the AeST RAR for isothermal spheres in
certain cases shares qualitative features also found in the
observational RAR for galaxy clusters, illustrating the potential of
AeST to address the shortcomings of MOND in galaxy clusters.
