Speaker
Description
The lattice formulation of finite-temperature field theory is readily extended,
via the Schwinger-Keldysh contour, to accomodate the definition of real-time
observables. Unfortunately, this extension also induces a maximally severe sign
problem, obstructing the computation of, for example, the shear viscosity. In
the large-N limit of certain field theories, including $O(N)$-symmetric scalar
fields, observables can be computed via a saddle point expansion (closely
connected to the Lefschetz thimble programme for alleviating the fermion sign
problem). This expansion continues to work for real-time observables. In this
talk we present lattice calculations of real-time dynamics in scalar field
theory at large N, both near equilibrium (transport coefficients) and far from
equilibrium.
