A random surface theory with non-trivial γstring

We measure by Monte Carlo simulations γstring for a model of random surfaces embedded in three dimensional Euclidean space-time. The action of the string is the usual Polyakov action plus an extrinsic curvature term. The system undergoes a phase transition at a finite valueβc of the extrinsic curvature coupling and at the transition point the numerically measured value ofγstring (λc) ≈ 0.27 ± 0.06. This is consistent with γ string (λ c ) = 1 4 , i.e. equal to the first of the non-trivial values of γstring between 0 and 1 2 .