The singularity theorems of Hawking and Penrose tell us that singularities are common
place in general relativity. Singularities not only occur at the beginning of the Universe at the …

Can NP-complete problems be solved efficiently in the physical universe? I survey
proposals including soap bubbles, protein folding, quantum computing, quantum advice …

We compare and contrast gravitational lensing, in the strong field limit, by the photon sphere
in spherically symmetric regular electrically charged (REC) black holes (0< b≤ b E) and with …

We show that, contrary to a widespread belief, one can overcharge a near extremal
Reissner-Nordström black hole by throwing in a charged particle, as long as the back …

It is shown that for a general nonstatic spherically symmetric metric of the Kerr-Schild class
several energy-momentum complexes give the same energy distribution as in the Penrose …

We investigate the key physical features that cause the development of a naked singularity,
rather than a black hole, as the end state of spherical gravitational collapse. We show that …

Spacetime singularities that arise in gravitational collapse are always hidden inside of black
holes. This is the essence of the weak cosmic censorship conjecture. The hypothesis, put …

An outstanding problem in gravitation theory and relativistic astrophysics today is to
understand the final outcome of an endless gravitational collapse. Such a continual collapse …

The (zeroth-order) energy of a particle in the background of a black hole is given by Carter's
integrals. However, exact calculations of a particle's self-energy (first-order corrections) are …

We innovate a systematic investigation of the weak cosmic censorship conjecture (WCCC)
using gedanken experiments involving black hole perturbations by test particles. We classify …