Time :  2021/04/08 (Thu.) 12:30
Place : R521, 5F, 2nd General Building, Nat'l Tsing Hua Univ.
Abstract: 
With the advances of observing technology, probing spacetimes under strong
gravitational fields, such as the vicinity of black holes, using their shadow
images will be an intensive field of research in the near future. In this talk,
I will illustrate the possibility of testing two specific Kerr-like black hole
spacetimes using, in particular, the apparent size of the M87* shadows. The first
Kerr-like model is constructed from a theory-agnostic approach and is characterized by
the breaking of its Z2 symmetry in the presence of spins.
This spacetime could be a good approximation to general black hole solutions in some
effective low-energy theories of a fundamental quantum theory of gravity. The second
model can be regarded as an effective rotating black hole spacetime in loop quantum
gravity. This spacetime is everywhere-regular and it has several nice properties.
The features of the black hole shadows of these models, as well as their observational
implications, will be discussed.