Together with Sougato Bose, Mazumdar has proposed a bonafide test for the existence of the graviton in a table-top experiment, via witnessing gravitationally-mediated entanglement between two macroscopic superpositions of masses.[2] A positive test of this phenomenon would establish experimentally that gravity is quantum mechanical in nature, and establish the existence of the graviton.[3]
The test crucially depends on the quantum nature of gravity, creating non-classical states of matter, and local operation and quantum communication (LOQC).[4]
His work has focused on multi field theories of inflation, such as assisted inflation,[7] visible sector inflation such as MSSM inflation.[8] He has worked on the ghost-free and singularity-free construction of infinite derivative theories of gravity,[9] which can potentially resolve the Schwarzschild singularity for mini black holes, yielding a non-singular compact object without event horizon, and cosmological singularities. He has also conjectured with Koshelev that astrophysical black hole has no curvature singularity and devoid of an event horizon,[10] in infinite derivative theories of gravity, because the scale of non-locality in gravitational interaction can engulf the gravitational radius of the compact object.
At time scales and at distances below the effective scale of non-locality the gravitational interaction weakens sufficiently enough that a finite pressure from normal matter satisfying null, strong and weak energy conditions can avoid forming blackhole with event horizon and cosmological singularities.