Universality and scaling behavior of RG gauge actions

We study universality and scaling properties of RG gauge actions (Iwasaki and DBW2). In the first part we consider the critical temperature T_{c} and compute the reference energy scale r_{0} for critical couplings \beta_{c} corresponding to N_{t}=3,4,6,8. The universality of T_{c}r_{0} between Iwasaki and Wilson action is confirmed and the scaling behavior of the Iwasaki action is found to be better than the one for the Wilson action. The results for the DBW2 action show larger lattice artefacts. A continuum value T_{c}r_{0}=0.7498(50) is extracted. We compute also the glueball masses for the states 0^{++} and 2^{++}, investigate the scaling of m_{0^{++}}r_{0} and m_{2^{++}}r_{0} and point out practical problems which are due to the violation of positivity present in the RG actions.