Current main focus is in various aspects of quantum gravity with concentration on the loop approach.
Other areas of interest:
Quantum effects in black holes.
Black hole interiors.
Higher dimensional space-times.
Universe models with ordinary matter and exotic dark matter/energy.
Detailed mathematical studies of the spherically symmetric gravitational field equations.
The cosmological Einstein-perfect fluid-scalar field equations and a development for the solution of the Cauchy problem in this system.
Modifications to Einstein gravity.
Relativistic particle, fluid and plasma mechanics coupled to weak-field relativistic gravity.
Gravastars as an alternative to black holes.
Topological boundary conditions in loop quantum gravity.
Some current projects, experiencing various levels of attention: a discrete phase-space representation of relativistic quantum field theory, Loop quantum gravity, analytic models of gravitational collapse, ..?
A partial list of publications.
Book: The General Theory of Relativity: A Mathematical Exposition by A. Das and A. DeBenedictis .
Some fun stuff not related to my research.
Personal home page (sporadically maintained).