Classical-statistical lattice simulations provide a useful approximation to out-of-equilibrium quantum field theory, but only for systems exhibiting large occupation numbers, and only for phenomena that are not intrinsically quantum mechanical in nature. In certain special circumstances, it can be appropriate to initialize such real-time simulations with quantum-like zero-point fluctuations....

In the Standard Model the electroweak phase transition is a crossover, but in many beyond the Standard Model theories the transition is of first order. Strong first order PTs could produce gravitational waves that might be detectable by the Laser Interferometer Space Antenna (LISA). Perturbation theory is commonly used to estimate the parameters that enter the calculation of gravitational wave...

In the study of cosmological phase transitions, even apparently weakly coupled theories develop strongly coupled sectors. For static equilibrium quantities, lattice methods have been developed to tackle this which are able to yield unambiguously correct results up to small statistical errors. For real-time quantities, the problem is more complicated. In this talk, I will review approaches to...

In this talk I will briefly present our recent RBC/UKQCD result for isospin-breaking corrections to leptonic decay rates. With the leading systematic uncertainty coming from unknown finite-volume effects, I will discuss the analytical evaluation of these at order $1/L^3$. This order is particularly complicated in certain formulations of finite-volume QED, and requires better understanding for...