Abstract
Vacuum energy sequestering is a mechanism for cancelling off the radiative corrections to vacuum energy. The most comprehensive low energy model, proposed in [1], has the ability to cancel off radiative corrections to vacuum energy for loops of both matter and gravitons, in contrast to earlier proposals. Here we explore the framework and cosmological consequences of this model, which we call Omnia Sequestra, owing to its ability to sequester all. A computation of historic integrals on a cosmological background reveals some subtleties with UV sensitivity not seen in earlier models, but which are tamed in a Universe that grows sufficiently old. For these old Universes, we estimate the size of the radiatively stable residual cosmological constant and show that it does not exceed the critical density of our Universe today. We also study the effect of phase transitions, both homogeneous and inhomogeneous, and find that generically spacetime regions with a small cosmological constant do not need to be fine-tuned against the scale of the transition, a result which is now seen to hold across all models of sequestering. The model is developed in other ways, from its compatibility with inflation, to the correct inclusion of boundaries and the geometric consequences of certain choices of boundary data.
Highlights
Low energies we are only sensitive to their rigid behaviour
We have explored the cosmological framework of Omnia Sequestra, the generalised theory of vacuum energy sequestering with the capacity to enforce cancellation of all radiative corrections to vacuum energy, including both matter and graviton loops [11]
As in older models of sequestering, the cosmological behaviour relies on certain historic integrals, their structure is different in subtle but important ways
Summary
√2 −g δSm δgμν is the energy momentum tensor The ratio of the latter two equations constrains the spacetime average of the Gauss-Bonnet term in terms of the boundary fluxes, RGB =def. The Weyl tensor is scale invariant so it too is immune from vacuum energy, while RGB is constrained by (2.5) The latter contains a potential source of instability through its dependence on Λ and θ, which receive radiative corrections that go as δΛ ∼ O(M 4) and δθ ∼ O(1) log(M/m), where M is the effective field theory cut-off and m is a typical mass scale [18].
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