A renormalization group flow analysis of meson condensations in dense matter

We present a renormalization-group (RG) flow argument for s-wave kaon condensation in dense nuclear-star matter predicted in chiral perturbation theory. It is shown that it is the relevant mass term together with any attractive interaction for the kaon in medium that triggers the instability. We show that a saddle point of multi-dimensional RG flow can imply a phase transition. Pion condensation is also analyzed along the same line of reasoning.