Benjamin Muntz - 'What can Solve the Cosmological Constant Problem?'

Thursday 15 Oct 2026, 16:00 → 18:00 Asia/Seoul

In this talk I will share some reflections on the cosmological constant problem (CCP) and what may possibly solve it. 

 

In the first part, I will present an example of a new mechanism for addressing the problem of radiative corrections to vacuum energy based on global constraints arising from a lapse function in a higher-dimensional gravitational theory. Inspired by Horava-Lifshitz gravity, we consider a 5d spacetime with anisotropic scaling along a compact extra dimension, while preserving Lorentz invariance in 4d. In the deep IR, the lapse generates a global constraint on the 4d geometry, closely analogous to vacuum energy sequester (VES). Although the two theories differ, radiative contributions to SM vacuum energy nevertheless cancel in a similar fashion at all orders.

 

In the second part, I will then reinterpret the CCP from the point of view of (-1)-form global symmetries associated with continuous couplings. We argue that GR with a cosmological constant actually contains two (-1)-form global symmetries. (Note: it is generally argued that quantum gravity should not admit any global symmetries!) I will show how flat gauging one yields Henneaux-Teitelboim unimodular gravity; gauging both leads to the local formulation of VES, which solves the CCP. Building on this intuition, we propose a general diagnostic for determining whether a gravitational EFT admits a CCP. I will also discuss parallels with the strong CP problem in QCD, where topological susceptibility diagnoses the problem.