  We study the effects of gauge-field fluctuations on the free energy of a
homogeneous color superconductor in the color-flavor-locked (CFL) phase.
Gluonic fluctuations induce a strong first-order phase transition, in contrast
to electronic superconductors where this transition is weakly first order. The
critical temperature for this transition is larger than the one corresponding
to the diquark pairing instability. The physical reason is that the gluonic
Meissner masses suppress long-wavelength fluctuations as compared to the normal
conducting phase where gluons are massless, which stabilizes the
superconducting phase. In weak coupling, we analytically compute the
temperatures associated with the limits of metastability of the normal and
superconducting phases, as well as the latent heat associated with the
first-order phase transition. We then extrapolate our results to intermediate
densities and numerically evaluate the temperature of the fluctuation-induced
first-order phase transition, as well as the discontinuity of the diquark
condensate at the critical point. We find that the London limit of magnetic
interactions is absent in color superconductivity.
