Spin dynamics of La2CuO4 and the two-dimensional Heisenberg model.

The spin-lattice relaxation rate 1/[ital T][sub 1] and the spin-echo decay rate 1/[ital T][sub 2[ital G]] for the two-dimensional Heisenberg model are calculated using quantum Monte Carlo and maximum-entropy analytic continuation. The results are compared with recent experiments on La[sub 2]CuO[sub 4], as well as predictions based on the nonlinear [sigma] model.