Usha Kulshreshtha is an Indian theoretical physicist, specializing in the Dirac's instant-form and light-front quantization of quantum field theory models, string theory models and D-brane actions using the Hamiltonian, path integral and BRST quantization methods, constrained dynamics, construction of gauge theories and their quantizaton under gauge-fixing as well as study of boson stars, and wormholes in general relativity and gravity theory.

Daya Shankar Kulshreshtha is an Indian theoretical physicist, specializing in formal aspects of quantum field theory, string theory, supersymmetry, supergravity and superstring theory, Dirac's instant-form and light-front quantization of field theories and D-brane actions. His work on the models of gravity focuses on the studies of charged compact boson stars and boson shells.