Nonperturbative test of nucleation calculations for strong phase transitions

Nucleation rate computations are of broad importance in particle physics and cosmology. Perturbative calculations are often used to compute the nucleation rate <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi mathvariant="normal">Γ</a:mi></a:math>, but these are incomplete. We perform nonperturbative lattice simulations of nucleation in a scalar field theory with a tree-level barrier, computing a final result extrapolated to the thermodynamic and continuum limits. Although the system in question should be well described by a complete one-loop perturbative calculation, we find only qualitative agreement with the full perturbative result, with a 20% discrepancy in <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mo stretchy="false">|</d:mo><d:mi>log</d:mi><d:mi mathvariant="normal">Γ</d:mi><d:mo stretchy="false">|</d:mo></d:math>. Our result motivates further testing of the current nucleation paradigm.