Theory Working Group

Hamiltonian Renormalisation

by Mr Klaus Liegener (Friedrich-Alexander-University Erlangen-Nurnberg)

Europe/Stockholm
Nortdita 132:028

Nortdita 132:028

Description
We study the question whether it is possible to reformulate the Wilsonian renormalisation group non-perturbatively directly at the operator (Hamiltonian) level. Hamiltonian renormalisation would be the natural route to follow if one had easier access to an interacting Hamiltonian operator rather than to a path integral, at least in the presence of UV and/or IR cut-off, which is generically the case in complicated gauge theories such as General Relativity. Our guiding principle for the definition of the direct Hamiltonian renormalisation group is that it results in the same continuum theory as the covariant (path integral) renormalisation group. We will investigate this direct Hamiltonian Renormalisation for the case of the free massive quantum scalar field and point out its necessity in a concrete cosmological example for Quantum Gravity.