Talk presented by Tereza Mendes

Parallel Session: Spin Models I

Thursday July 1st, 15.10 - 15.30, Room B

Numerical evidence for Goldstone effects on the three-dimensional O(4)-model

Abstract: We investigate the three-dimensional O(4)-model on $16^3$--$64^3$ lattices as a function of the magnetic field $h$. Below the critical point, in the broken phase, we confirm explicitly the $h^{1/2}$ dependence of the magnetization and the corresponding $h^{-1/2}$ divergence of the longitudinal susceptibility, which are predicted from the existence of Goldstone modes. At the critical point the magnetization follows the expected finite-size-scaling behavior, with critical exponent $\delta = 4.85(1)$.

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