B-Mode auto-bispectrum due to matter bounce
  Primordial Gravitational waves leave polarization imprints on the Cosmic
Microwave Background (CMB). In this article, we investigate polarization
bispectrum, which is also referred to as the B-mode auto bispectrum, due to a
matter bounce Universe. For simplicity, we consider a minimally coupled
Einstein frame and obtain an analytical integral expression for the bispectrum
and numerically perform the integration. We find that the signal-to-noise ratio
is small, when compared with the same in the inflationary paradigm and hence
quite difficult to detect in the future experiments. Thus a detection of tensor
mode bispectrum in future will be helpful in ruling out matter bounce model.
Also, to ease the numerical evaluation of the bispectrum, we develop and use
various techniques. We believe that these techniques can be used in various
other contexts.
