activity
20242026
collaborators

12 papers

gr-qc2026

When one sign is not enough: 2+1 circular motion Unruh effect at low energies

Leo J. A. Parry, Christopher J. Fewster, Jorma Louko

We address the circular motion Unruh effect in 2+1 spacetime dimensions, as probed by a pointlike Unruh-DeWitt detector coupled to a massless scalar field. The effective temperatur…

math-ph2026

On the construction of Hadamard states from Feynman propagators

Christopher J. Fewster, Alexander Strohmaier

The Wightman two-point function of any Hadamard state of a linear quantum field theory determines a corresponding Feynman propagator. Conversely, however, a Feynman propagator dete…

math-ph2026

Polarisation sets of Green operators for normally hyperbolic equations

Christopher J. Fewster

The polarisation set of a vector-valued distribution generalises the wavefront set and captures fibre-directional information about its singularities in addition to their phase spa…

gr-qc2026

Waiting around for Unruh

Leo J. A. Parry, Diego Vidal-Cruzprieto, Christopher J. Fewster +1

How long does a uniformly rotating observer need to interact with a quantum field in order to register an approximately thermal response due to the circular motion Unruh effect? We…

math-ph2025

Hadamard states for decomposable Green-hyperbolic operators

Christopher J. Fewster

Hadamard states were originally introduced for quantised Klein-Gordon fields and occupy a central position in the theory of quantum fields on curved spacetimes. Subsequently they h…

math-ph2025

Coupled Proca theories: Green-hyperbolicity, quantization and applications to polarization measurement

Christopher J. Fewster, Christiane K. M. Klein

The Proca field describes a massive relativistic spin- particle and was originally formulated in Minkowski spacetime. Here we consider a variety of generalizations in globally h…