Functional RG flow of the effective Hamiltonian action

TL;DR

This paper introduces a functional renormalization group equation for the quantum effective Hamiltonian action, enabling non-perturbative analysis of quantum systems, including those with non-quadratic Hamiltonians, and discusses extensions to quantum field theories.

Contribution

It develops a non-perturbative RG framework for the effective Hamiltonian action, applicable to complex quantum systems and field theories, including fermionic degrees of freedom.

Findings

Computed vacuum energy and gap in quantum mechanical models

Formulated a Lorentz covariant approach for scalar field theories

Discussed extensions to quantum field theories with fermions

Abstract

After a brief review of the definition and properties of the quantum effective Hamiltonian action we describe its renormalization flow by a functional RG equation. This equation can be used for a non-perturbative quantization and study also of theories with bare Hamiltonians which are not quadratic in the momenta. As an example the vacuum energy and gap of quantum mechanical models are computed. Extensions of this framework to quantum field theories are discussed. In particular one possible Lorentz covariant approach for simple scalar field theories is developed. Fermionic degrees of freedom, being naturally described by a first order formulation, can be easily accommodated in this approach.