Quantum gravity has been a central challenge in theoretical physics. Recently, with the fast development of quantum information science, there is a growing interest in exploring a different parameter space of quantum gravity — superposition of massive objects, and their entanglement and decoherence caused by gravity. We explore the gravitational superposition, entanglement and decoherence of inflationary cosmological perturbations. A boundary term is identified which causes faster decoherence than the previously understood rate from bulk interactions. This gravitational decoherence can be considered together with the recent studied quantum noise of cosmological perturbations, and shed light for the observational search for quantum gravity effects.
Yi Wang got his PhD in 2009 at the Institute of Theoretical Physics, Chinese Academy of Sciences. After that he was postdoc at McGill University and IPMU, and the Stephen Hawking Advanced Fellow at the University of Cambridge. He is now an Associate Professor at the Hong Kong University of Science and Technology. His research interest spans many areas of theoretical cosmology, including inflation, gravitational waves, dark energy, dark matter and black hole physics.