Superfluids and the Cosmological Constant Problem

Abstract

We introduce a novel method to circumvent Weinberg's no-go theorem for self-tuning the cosmological vacuum energy: a Lorentz-violating finite-temperature superfluid can counter the effects of an arbitrarily large cosmological constant. Fluctuations of the superfluid result in the graviton acquiring a Lorentz-violating mass and we identify a unique class of theories that are pathology free, phenomenologically viable, and do not suffer from instantaneous modes. This new and hitherto unidentified phase of massive gravity propagates the same degrees of freedom as general relativity with an additional Lorentz-violating scalar that is introduced by higher-derivative operators in a UV insensitive manner. The superfluid is therefore a consistent infrared modification of gravity. We demonstrate how the superfluid can degravitate a cosmological constant and discuss its phenomenology.

35 pages

References in corpus (18)

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Cited by in corpus (12)

• A local resolution of the Hubble tension: The impact of screened fifth forces on the cosmic distance ladder
• The Novel Probes Project -- Tests of Gravity on Astrophysical Scales
• Beyond the Standard Model Explanations of GW190521
• Pixelated Dark Energy
• Splashback in galaxy clusters as a probe of cosmic expansion and gravity
• Unified Superfluid Dark Sector
• Screened Fifth Forces Mediated by Dark Matter-Baryon Interactions: Theory and Astrophysical Probes
• Symmetric Superfluids
• Gravity in $d=2+\epsilon$ dimensions and realizations of the diffeomorphisms group
• Well-Tempered Cosmology
• Cosmological cancellation of the vacuum energy density
• Mapping the Weak-Field Limit of Scalar-Gauss-Bonnet Gravity