10th International Conference on Gravitation and Cosmology: New Horizons and Singularities in Gravity (ICGC 2023)

Dyonic Kerr-Sen black holes revisited: shadow profiles and consequences

Not scheduled

15m

IIT Guwahati

Oral Classical & Quantum Gravity Classical & Quantum Gravity

Speaker

Dr Soumya Jana (Sitananda College)

Description

Black holes with dyonic charges in Einstein-Maxwell-dilaton-axion supergravity theory are revisited in the context of black hole shadows. We consider static as well as rotating (dyonic Kerr-Sen) black holes. The matter stress-energy tensor components, sourced by the Maxwell, axion and dilaton fields satisfy the standard energy conditions. The analytical expressions for the horizon and the shadow radius of the static
spacetimes demonstrate their dependence on $P^2+Q^2$ ($P$, $Q$ the magnetic and electric charges, respectively) and the mass parameter $M$.
The shadow radius lies in the range $2M Constraints on $P$ obtained from other astrophysical effects, such as the observed temperature of clouds of warm ionized medium (WIM) in the Milky Way and the Parker bound on the flux of magnetic monopoles, are however expected to be far more stringent though rigorous analyses along these lines is lacking. Future refined imaging (shadow) observations
will surely help in improving the bound on $P$ arrived at here.

Reference: S. Jana and S. Kar, Phys. Rev. D 108, 044008 (2023).