B-Pol Science


b-pol renderWe propose a Class M space mission aimed at detecting the primordial gravitational waves generated during inflation, in response to the Call for Proposals of ESA Cosmic Vision 2015-2025.

The B-Pol proposal is for a space mission (prepared as a class M mission within the framework of the recent ESA Cosmic Vision 2015-2025 call) aimed at detecting the primordial gravitational waves generated during inflation.

The search for a B mode component of the polarized CMB (Cosmic Microwave Background) anisotropy consitutes the next frontier of CMB research. The ESA mission Planck will establish stringent constraints on the nature of the scalar primordial cosmological perturbations through greatly improved measurements of the temperature and E-mode (gradient) component of the CMB polarization. Nevertheless, even with such an accurate characterization of the scalar perturbations, a decisive confirmation of inflation will be lacking, and large uncertainties in the allowed inflationary potentials will persist. Inflation predicts the existence of primordial gravitational waves on cosmological scales. Their detection would establish firmly the existence of a period of inflationary expansion in the early universe and would confirm the quantum origin of cosmological fluctuations that led to the large scale structure observed today. The search for primordial B-mode (curl component) polarization of the CMB provides the only opportunity to detect in the foreseeable future the imprint of these gravitational waves.

Detecting and characterizing the B-mode polarization signal does not require high-angular resolution since most of the signal lies on angular scales larger than a degree. What is needed is greatly enhanced sensitivity, full-sky coverage, and exquisite control of systematic errors. The B-Pol instrument will provide approximately two orders of magnitude of improvement in sensitivity compared to PLANCK on the angular scales of interest.

" Proving that cosmic inflation happened would constitute a discovery of profound and lasting significance. The proposed B-Pol satellite is just what is needed to achieve this breakthrough."

Stephen Hawking

"Positive detection would be epochal, both for cosmology and for fundamental physics."

Frank Wilczek

"CMB Polarization measurements have the potential to have truly revolutionary impact on cosmology. I strongly endorse the science goals of the B-Pol program.",

David Spergel