Abstract: In this talk, I will discuss cosmology with new measurements of the cosmic microwave background (CMB) polarization. In the coming decade, a twisting pattern in the polarization map, the so-called B-modes, will be one of our best avenues to probe the big open questions in cosmology, which are of fundamental relevance to high energy physics. For example, B-modes are produced by primordial gravitational waves, which are predicted by cosmic inflation theory but have not yet been detected by observations. Since gravitational lensing of the CMB generates B-modes as well, a precise measurement of B-modes is also important for extracting lensing signals to probe the physics of large-scale structure and neutrinos.

I will first introduce the importance of B-mode cosmology. Then, I will discuss ongoing efforts in CMB B-mode cosmology and the great potential of future CMB experiments in this field.