Constraints on the fundamental string coupling from future B-mode experiments
Pogosian, Levon (Simon Fraser University)

We study signatures of cosmic superstring networks containing strings of multiple tensions and Y-junctions, on the cosmic CMB temperature and polarization spectra. We focus on the crucial role of the string coupling constant $g_s$, and show that the number density and energy density of the scaling network are dominated by different types of string in the $g_s \sim 1$ and $g_s \ll 1$ limits. This can lead to a potentially observable shift in the position of the B-mode peak --- a distinct signal that could allow one to constrain $g_s$. We forecast the bounds from upcoming and future CMB polarization experiments on the value of $g_s$.