B-Mode auto-bispectrum due to matter bounce

Understand

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.