Speaker: Markus Luty
Title: Hamiltonian Truncation as Effective Field Theory
Room: 3024
Zoom: https://zoom.us/j/186024391
Host: Markus Luty
Abstract: Hamiltonian truncation is a variational approximation of a quantum system based on projecting the Hilbert space to a finite-dimensional subspace and numerically diagonalizing the resulting finite-dimensional Hamiltonian. This method has recently attracted renewed interest for applications to quantum field theory, but is much less developed than lattice quantum field theory. In this talk, I will describe the effective field theory of Hamiltonian truncation, which gives a systematic understanding of the errors made in the truncation and how to correct for them. The effective Hamiltonian has novel features such as non-Hermiticity and non-locality, both of which are controlled in a systematic expansion. Numerical results for 2D phi^4 theory show that the effective Hamiltonian reduces the errors in agreement with theoretical expectations.
