Surprising Dark Implications of a Supersymmetric Gravity Sector
Duration: 1 hour 5 mins
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| Description: |
Seminar presented at the Cosmology Lunch Seminar on the 6th of June 2022 by Cliff Burgess, from McMaster University and the Perimeter Institute.
Slides available at https://www.dropbox.com/sh/m0hrsxgg1tgltyy/AAASAcgjbsNBj6yQapKg6C_za?dl=0. |
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| Created: | 2022-06-14 10:11 |
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| Collection: | Cosmology Lunch Seminar |
| Publisher: | University of Cambridge |
| Copyright: | Francesco Muia |
| Language: | eng (English) |
| Distribution: |
World
(downloadable)
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| Explicit content: | No |
| Aspect Ratio: | 16:9 |
| Screencast: | Yes |
| Bumper: | UCS Default |
| Trailer: | UCS Default |
| Abstract: | This talk explores consequences of accidental approximate scale invariances combined with a relatively supersymmetric gravity sector, both of which are argued to be robust consequences of UV physics (like string theory). Taken together these can be more than the sum of their parts, and suggest the low-energy world around us should consist of non-supersymmetric particle physics coupled to a rich dark sector built from supersymmetric gravity. A core prediction is that all particle masses arise proportional to the vev, v, of a dilaton field with a pattern where Standard Model masses, M, neutrino masses, m, and the Planck mass satisfy Mp/M ~ M/m ~ v, suggesting v ~ 10^{15}. The framework also predicts the scalar potential for v, and this has both AdS and dS solutions without any need for problematic uplifting. The potential arises as a function of log v and so can give exponentially large values for v using only input parameters of order log v ~ 70. Tantalizingly, at its minimum the potential scales as V_min ~ Mp^4/v^8, and so shares the scaling of the phenomenologically successful numerology V_min ~ (M^2/Mp)^4. The prefactor is somewhat model-dependent, but in the known examples predicts V_min ~ F*F/[v^2 (log v^2)^5], where F*F = Ms^4 sets the supersymmetry breaking scale in particle physics. For Ms ~ 100 TeV and v ~ 10^{15} this predicts V_min ~ 10^{-91} Mp^4: not yet nailing the Dark Energy density (10^{-120} Mp^4), but at least taping it down better than usual. Preliminary phenomenological implications are drawn assuming this framework eventually succeeds in further pushing down V_min, and include intriguing cosmologies that (for free) seem to dynamically implement a recent proposal for resolving the Hubble tension (by modifying the electron mass around recombination). |
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