Temperature-dependent spin susceptibility in a two-dimensional metal

We consider a two-dimensional electron system with Coulomb interaction between particles at a finite temperature T. We show that the dynamic Kohn anomaly in the response function at 2kF leads to a nonanalytic, linear-in-T correction to the spin susceptibility, δχ(T)=aT, the same as in systems with short-range interaction. We show that the singularity of the Coulomb interaction at $q=0$ does not invalidate the expansion of the prefactor a in powers of rₛ, but makes the expansion nonanalytic.