Jul 15 – 19, 2024
Perimeter Institute for Theoretical Physics
America/Toronto timezone

A Cosmic Glitch in Gravity

Jul 17, 2024, 3:00 PM
15m
PI/1-100 - Theatre (Perimeter Institute for Theoretical Physics)

PI/1-100 - Theatre

Perimeter Institute for Theoretical Physics

190
Contributed Talk Contributed Talks

Speaker

Mr Yunfei Wen (California Institute of Technology)

Description

We present a model that modifies general relativity on cosmological scales, specifically by having a 'glitch' in the gravitational constant between the cosmological (super-horizon) and Newtonian (sub-horizon) regimes. This gives a single-parameter extension to the standard ΛCDM model, which is equivalent to adding a dark energy component, but where the energy density of this component can have either sign. Fitting to data from the Planck satellite, we find that negative contributions are, in fact, preferred. Additionally, we find that roughly one percent weaker superhorizon gravity can somewhat ease the Hubble and clustering tensions in a range of cosmological observations. Therefore, the extra parametric freedom offered by our model deserves further exploration, and we discuss how future observations may elucidate this potential cosmic glitch in gravity, through a four-fold reduction in statistical uncertainties.

Keywords Modified Gravity, CMB
arXiv reference, if applicable: arXiv:2311.03028

Primary author

Mr Yunfei Wen (California Institute of Technology)

Co-authors

Prof. Douglas Scott (University of British Columbia) Prof. Niayesh Afshordi (University of Waterloo/Perimeter Institute) Dr Lukas Hergt (University of British Columbia)

Presentation materials

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External references