Thermodynamics of SU(N) gauge theories in 2+1 dimensions in the $T<T_c$ regime

We present Monte Carlo results for the thermodynamics of pure SU(N) gauge theories with $N=2,\mathrm{.}\mathrm{.}\mathrm{.},6$ in 2+1 dimensions. We focus on the confined phase region $T<T_c$ and study thermodynamics variables such as the trace of the energy-momentum tensor, pressure, energy and entropy density using the integral method. We also investigate scaling properties with $N$ of the different observables. We compare our results with a gas of free glueballs and the bosonic string predictions for the Hagedorn spectrum.