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Surprising Dark Implications of a Supersymmetric Gravity Sector

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Zoom link: https://stonybrook.zoom.us/j/2816482971?pwd=TWpaN1hpd2laZzNxcGVJSkVGUVFDUT09.

This talk explores surprises that emerge as 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 the pattern where Standard Model masses, M, neutrino masses, m, and the Planck mass satisfy Mp/M \sim M/m \sim v, suggesting v is order 1e15. 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 70. Tantalizingly, at its minimum the potential evaluates to the fourth power of an energy E = (weak scale squared)/(Planck mass) that scales with v in the same way as a famous phenomenologically successful numerology. The prefactor is somewhat model-dependent, but in the known examples predicts the potential at its minimum to be suppressed by two powers of v (and five powers of log v), relative to the supersymmetry breaking scale in particle physics. For supersymmetry broken at 100 TeV this predicts a dark energy density of 1e(-91) in Planck units: not yet nailing the Dark Energy density—1e(-120)—but at least taping it down better than usual. Preliminary phenomenological implications are drawn assuming this framework eventually succeeds in further pushing down the minimum of V, 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).

This talk is part of the Cosmology Lunch series.

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