Vortex-glass transition in three dimensions

We investigate the possibility of a vortex-glass transition in a disordered type-II superconductor in a magnetic field in three dimensions by numerical studies of a simplified model. Monte Carlo simulations at finite temperature and domain-wall renormalization-group calculations at T=0 indicate that d=3 is just above the lower critical dimension ${\mathit{d}}_{\mathit{l}}$, though the possibility that ${\mathit{d}}_{\mathit{l}}$=3 cannot be definitely ruled out. A comparison is made with XY and Ising spin glasses. The (effective) correlation-length exponent \ensuremath{\nu} and dynamical exponent z are in fairly good agreement with experiment.