Quantum Gravity Seminar: Aaron Held

Speaker: Aaron Held (Ecole Normale Supérieure, Paris)

Spacetime coordinates: Wed @ 13:30, Auditorium A

Zoom Link: https://ucph-ku.zoom.us/j/9295289933?omn=67282578176

Title: Nonlinear quantum gravity in four dimensions: From quantisation to phenomenology

Abstract: This talk will employ effective-field theory (EFT) methods to confront fundamental proposals for the quantisation of gravity with current data from particle physics and gravitational astrophysics. For concreteness, I will restrict to (3+1) dimensional field theory. In this context, I will review the tension between unitarity, perturbativity, and vacuum stability. This leads me to the available scenarios of asymptotic freedom and asymptotic safety.

The first main part of my talk will focus on well-developed phenomenological constraints in the particle physics sector. First, I will summarise the conditions under which quantum gravity can complete the full Standard Model. Then, I will focus on the distinct predictivity of different scenarios and on a Bayesian framework to quantitatively compare the resulting phenomenology with current and future collider data.

The second part of my talk will focus on the underlying gravitational strong-field dynamics. First, I will highlight an unscrutinised inference step in folk no-go theorems to dismiss higher-derivative dynamics. The resulting reassessment provides a new perspective on asymptotically free quantum gravity and has already led to novel methods for nonlinear time evolution. The latter opens the door to a robust comparison with gravitational-wave data and to more general quantitative exploration of gravitational strong-field dynamics.