On the inclusion of statistical matter in the non-relativistic limit of NS-NS supergravity

We combine techniques from kinetic theory and string dualities to couple statistical matter to a non-relativistic (NR) supergravity background, enabling the theory to be formulated in a T-duality invariant form. Similarly to the relativistic case, we explicitly demonstrate that, in the NR limit, the many-strings system necessitates a viscous fluid description for the statistical matter. This is achieved using the generalized energy-momentum tensor of a perfect fluid, which remains covariant under T-duality.