Exact Results in Quantum Theory

We study the quantization of linearized gravity on de Sitter spacetime.We work in the transverse-traceless gauge and consider the (pseudo-) state obtained by Wick rotation, called the Euclidean vacuum. We show that the Euclidean vacuum is not fully gauge invariant and does not generate a positive state on the physical phase space. This fact can be traced back to the existence of Killing isometries.We show how to modify the Euclidean vacuum to obtain a fully gauge invariant and positive Hadamard state. The modified state is however not invariant under the full symmetry group of de Sitter space.

Link: https://uw-edu-pl.zoom.us/j/92533160394?pwd=dmsyNVVrelhjbDJpRmJtaGFaR1BmQT09
Meeting ID: 925 3316 0394
Passcode: 839945