ITC Colloquium

This week's ITC Colloquium is presented by Cumrun Vafa from Harvard.

String Theory and the Fading Dark Sector

In this talk I explain how string theory leads to the unification of the dark sector: The smallness of dark energy leads to the existence of dark matter. Moreover I review a 2019 stringy model of the evolving dark sector, involving the prediction that the size of the extra dimensions of string theory cannot be stabilized and continue evolving together with the mass of the dark matter viewed as gravity waves in these extra dimensions. It turns out that this model anticipated the recent observations of DESI and DES teams leading to similar significance over LCDM as the CPL parameterization, but without any phantom behavior. Moreover this leads to the prediction of a long range attractive force in the dark sector whose strength is 0.5% of the gravitational force.