Color Superconductivity in High Density Effective Theory

In this talk, I discuss the recent development in color superconductivity in terms of effective field theory. By investigating the Cooper pair gap equations at high density, we see that the effective theory simplifies the gap analysis very much, especially in finding the ground state, the precise form of the gap, and the critical temperature. Furthermore, the effective theory enables us to estimate the critical density for color superconductivity, which is found to be around $230~{\rm MeV}$ in the hard-dense-loop approximation. Finally, I briefly mention the low-lying spectra of color superconductor at high density.