[HEG] Fighting non-locality with non-locality: microcausality and boundary conditions in QED
Date and Time
Location
Zoom
Who: Philipp Hoehn (Okinawa Institute)
Title: Fighting non-locality with non-locality: microcausality and boundary conditions in QED
Abstract:
Abstract:
In gauge theories, globally charged observables necessarily depend non-locally on the kinematical fields, with this dependence extending to the asymptotic boundary of spacetime. I will explain that nevertheless a subset of such observables can be consistently regarded as local to the bulk, in a manner that respects microcausality and leaves locality properties of uncharged observables untouched. A sufficient condition for this is to impose kinematically non-local boundary conditions on the large gauge sector of the theory, and to invoke a relational notion of localization for observables. This reveals a somewhat underappreciated link between boundary conditions, and different notions of microcausality and locality. I will illustrate this observation through a case study in scalar QED, describing non-local boundary conditions that allow a large family of charged observables on a codimension-1 bulk surface to be viewed as local to that surface. I will explain how this setup may be understood in terms of a preferred dynamical gauge frame, and how many features of the theory (such as microcausality, the vacuum state, and the net of algebras of observables) depend on the choice of this frame.
The zoom link for this talk will be:
Krishan Saraswat is inviting you to a scheduled Zoom meeting.
Topic: UCSB HEP and Gravity Seminar
Time: May 14, 2026 04:00 PM Pacific Time (US and Canada)
Join Zoom Meeting
https://ucsb.zoom.us/j/88173255373?pwd=NgmORsbonH0GDXCe32hBxpIpbWYFiO.1
Meeting ID: 881 7325 5373
Passcode: 480494
