Oscillons in a hot heat hath

In models of real scalar fields with degenerate double-well potentials, spherically symmetric, large amplitude fluctuations away from the vacuum are unstable. Neglecting interactions with an external environment, the evolution of such configurations may entail the development of an oscillon, a localized, nonsingular, time-dependent configuration which is extremely long lived. In the present study we investigate numerically how the coupling to a heat bath influences the evolution of collapsing bubbles. We show that the existence and lifetime of the oscillon stage is extremely sensitive to how strongly the field is coupled to the heat bath. By modeling the coupling through a Markovian Langevin equation with viscosity coefficient gamma, we find that for gamma greater than or equal to 5x10(-4)m, where m is the typical mass scale in the model, oscillons are not observed.