Prospects of Constraining the Nature of Strong Gravity from the Event Horizon Telescope Data

Abstract

The remarkable agreement of general relativity (GR) with a host of experimental tests only adds to its phenomenal success. However, GR often falls short in explaining the dark sector and is associated with singularities which makes the quest for a more complete theory increasingly compelling. This may either involve modifications in the gravity sector or additions to the matter sector or both. These altenatives to GR need to be tested against available observations so that they can be established/falsified/constrained. Such deviations from GR are primarily expected in the strong-field regime and the horizon-scale images of black holes (BHs), M87* and Sgr A*, released by the Event Horizon Telescope (EHT) collaboration provides an unprecedented window to test the nature of strong gravity. In this talk, I shall discuss how the EHT data can be used to investigate possible deviations from the Kerr scenario and its possible consequences and implications.