Phase-ordering dynamics with an order-parameter-dependent mobility:: The large-n limit

The effect of an order-parameter-dependent mobility (or kinetic coefficient), given by lambda(<(phi)over right arrow>)proportional to(1 - <(phi)over right arrow>(2))(alpha), on the phase-ordering dynamics of a system described by an n-component vector order parameter is addressed at zero temperature in the large-n limit. In this limit the system is exactly soluble for both conserved and nonconserved order parameter; in the nonconserved case the scaling form for the correlation function and its Fourier transform, the structure factor, is established, with the characteristic length growing as L similar to t(1/2(1+alpha)). In the conserved case, the structure factor is evaluated and found to exhibit a multiscaling behavior, with two growing length scales differing by a logarithmic factor: L(1)similar to t(1/2(2+n)) and L(2)similar to(t/ln t)(1/2(2+alpha)). [S1063-651X(99)07601-1].