With Professor Tejinder P. Singh at TIFR, I investigated the role of gravity in the decoherence of the quantum states. Previous studies in Schrödinger-Newton (SN) dynamics have established the localization of a state vector with no evidence of the decoherence of the quantum state. We demonstrated that the quantum decoherence is a natural consequence of the metric fluctuations resulting from the noise in matter fields, within the framework of the stochastic gravity.

We propose a stochastic correction to the SN equation from the linearized Einstein-Langevin equation in Newtonian limit.  Using Karolyhazy’s phase variance method, we obtain the decoherence time and decoherence length of a gaussian wavepacket perturbatively, and demonstrate that the Diosi-Penrose criteria is automatically satisfied by the stochastic equation. Please refer http://arxiv.org/abs/1504.05892 for the details.