Real Time Dynamics At Large N

27 Jul 2021, 14:15
15m
Oral presentation Algorithms (including Machine Learning, Quantum Computing, Tensor Networks) Algorithms (including Machine Learning, Quantum Computing, Tensor Networks)

Speaker

Scott Lawrence (University of Colorado, Boulder)

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.

Primary author

Scott Lawrence (University of Colorado, Boulder)

Presentation materials