Collapse of the Gibbs measure for the dynamical $Φ^3_2$-models on the infinite volume

Kihoon Seong, Philippe Sosoe

Published 2024-06-05Version 1

We study the $\Phi^3_2$-measure in the infinite volume limit. This is the invariant measure for several stochastic partial differential equations including the parabolic and hyperbolic $\Phi^3_2$-models. In the large torus limit, we observe a concentration phenomenon of the $\Phi^3_2$-measure around zero, which is the single minimizer of the corresponding Hamiltonian for any fixed torus size. From our sharp estimates for the partition function, we obtain a triviality result for the $\Phi^3_2$-measure on infinite volume: the ensemble collapses onto a delta function on the zero field.