The diverse areas in which he contributed substantially include --- general relativity, electrodynamics, group theory and spectroscopy.
The corresponding generalisation, in the form of static solutions of the coupled, source-free Einstein-Maxwell equations, was discovered by Majumdar and Papapetrou independently[citation needed] in 1947.
While work continued on understanding these solutions better, a renewed interest in this metric was generated by the important observation of Israel and Wilson in 1972 that static black-hole spacetimes with the mass being equal to the magnitude of the charge are of Majumdar–Papapetrou form.
These and other aspects of the Majumdar–Papapetrou metric have attracted considerable attention on the classical side, as well as in the work and applications from the perspective of string theory.
In particular, the mass equal to charge aspect of these models was used extensively in certain string theoretic considerations connected to black hole entropy and related issues.
[8] Majumdar–Papapetrou geometries generalise axially symmetric solutions to Einstein-Maxwell equations found by Hermann Weyl to a completely nonsymmetric and general case.
The relation between the metric and the scalar potential is given by where the electrostatic field is normalised to unity at infinity.
The Majumdar–Papapetrou solution, thus, can be seen as early example of BPS configuration where static equilibrium results due to the cancellation of opposing forces.
Professor Majumdar was fascinated by the problem, because it was perhaps the only classical electrodynamical derivation that fetched Nobel prizes in a world dominated by the Quantum.
The great advantage of this approach is that the electromagnetic field becomes static and can be described by just two scalar potentials, which was a totally new formulation of the problem.
Armed with this insight and his new formulation of the problem, he derived, for the first time, a closed expression for the Cherenkov output in a biaxial crystal in terms of elliptic functions.
[12][13] A major contribution that resulted was the prediction of a new phenomenon called The Cherenkov analogue of conical refraction.
A surprising system of intersecting Cherenkov rings in a biaxial crystal at precisely defined particle energies was predicted.
Professor Majumdar's work on group theory has its origins in one of his early papers on molecular spectroscopy where a novel method for deriving the Clebsch-Gordan series and coefficients of SU(2) was discussed.