6 papers
On divergences in a four-derivative scalar field theory
Maegan Anderson, Sam Bateman, Franz Herzog +1
We perform a detailed diagrammatic analysis of the renormalisation of a family of asymptotically free, shift-symmetric four-derivative scalar field theories introduced by Holdom in…
Escape from Ostrogradsky via Hidden Ghost Parity
Sam Bateman, Neil Turok
We present a counterexample to Ostrogradsky's famous "no go" theorem as usually interpreted in quantum field theory (QFT), namely a four-derivative, UV-complete QFT with a consiste…
The free boundary problem in general relativity
Kostas Tzanavaris, Latham Boyle, Neil Turok
We study the action principle for space-times whose boundary is singular. We suggest that it is natural to treat the singularity as a {\it free} boundary, where the variation is un…
Visions in Quantum Gravity
Luca Buoninfante, Benjamin Knorr, K. Sravan Kumar +36
To deepen our understanding of Quantum Gravity and its connections with black holes and cosmology, building a common language and exchanging ideas across different approaches is cr…
Fixed points of classical gravity coupled with a Standard-Model-like theory
Latham Boyle, Neil Turok, Vatsalya Vaibhav
Coupling quantum field theory (QFT) \!-\! even free QFT \!-\! to gravity leads to well-known problems. In particular, the stress tensor (gravity's source) and its correl…
Black Mirrors: CPT-Symmetric Alternatives to Black Holes
Kostas Tzanavaris, Latham Boyle, Neil Turok
Einstein's equations imply that a gravitationally collapsed object forms an event horizon. But what lies on the other side of this horizon? In this paper, we question the reality o…