Black hole tidal charge constrained by strong gravitational lensing

TL;DR

This paper constrains the tidal charge of the supermassive black hole at our galaxy's center using strong gravitational lensing, showing it could be larger than that of smaller celestial objects, even if general relativity holds.

Contribution

It derives new constraints on the tidal charge of a supermassive black hole based on relativistic Einstein ring measurements in strong lensing.

Findings

Tidal charge could be significantly larger than that of the Sun or neutron stars.

High-precision lensing measurements can still accommodate a non-zero tidal charge.

Constraints are derived from the radius of the relativistic Einstein ring.

Abstract

Spherically symmetric brane black holes have tidal charge, which modifies both weak and strong lensing characteristics. Even if lensing measurements are in agreement with a Schwarzschild lens, the margin of error of the detecting instrument allows for a certain tidal charge. In this paper we derive the respective constraint on the tidal charge of the supermassive black hole (SMBH) in the center of our galaxy, from the radius of the first relativistic Einstein ring, emerging in strong lensing. We find that even if general relativistic predictions are confirmed by high precision strong lensing measurements, SMBHs could have a much larger tidal charge, than the Sun or neutron stars.