Research Projects

General relativity (GR) has been passed with precision in weak-field tests, but there are anomalies in the strong-field region, such as singularity formation and the accelerated expansion of the Universe. There is a growing need for more accurate and rigorous strong-field probes to test various aspects and predictions of GR. Black holes (BHs) are strong-field laboratories to test GR, and the gravitational waves detected by LIGO or Virgo from merging BHs provide state-of-the-art tools to constrain deviations from GR. The proposed work aims to use EHT results for shadow observables of BHs M87* and sgr A*, combined with gravitational wave observables from binary black hole mergers, to test the Kerr hypothesis in different curvature scales and constrain deviation parameters and charges or hairs associated with the background theory of gravity. New methods will be developed to precisely estimate black hole parameters and reduce the degeneracy of observational results in various model parameters. The proposed work will also consider surrounding dark matter and dark energy profiles to study their observational influence on black hole shadows and gravitational waves. This work will contribute to the larger global aim of finding the correct description(s) of gravity and provide more precise estimates of black hole parameters and astrophysical estimates of cosmological parameters.