Center for Theoretical Physics of the Universe (CTPU-PTC)

Parity violating graviton non-Gaussianity in alpha-vacuum.

by Maria Mylova (Ewha Womans U.)

CTPU Seminar room (IBS)

CTPU Seminar room



Non-Gaussianity in parity violating gravity has attracted a lots of attention in the last years. Previous works showed that the parity violating cubic Weyl tensor has vanishing graviton non-Gaussianity in exact de Sitter with Bunch-Davies initial conditions. More recent works considered the most general and model-independent tensor non-Gaussianity and found that only two shapes appear for the parity violating case, peaking in the squeezed and equilateral configurations. I will show that the de Sitter invariant state known as alpha-vacuum, can introduce non-vanishing parity-violating tensor non-Gaussianities for the parity violating cubic Weyl tensor, even in exact de Sitter space. This is due to the mixing by the Bogoliubov transformation of the positive and negative frequency modes of the Bunch-Davies initial conditions. I will present a new shape for the parity-violating tensor bispectrum which peaks in the flattened configuration. Finally, I will discuss the possible enhancement of the bispectra amplitudes, in this setup.