5–6 Feb 2018
CERN
Europe/Zurich timezone

Inflationary Perturbations in No-Scale Theories

5 Feb 2018, 11:35
20m
CERN

CERN

Speaker

Alberto Salvio (CERN)

Description

I discuss the inflationary perturbations in general (classically) scale-invariant theories. Such scenario is motivated by the hierarchy problem and provides natural inflationary potentials and dark matter candidates. All sectors (the scalar, vector and tensor perturbations) are discussed giving general formulae for the potentially observable power spectra, as well as for the curvature spectral index ns and the tensor-to-scalar ratio r. The conserved Hamiltonian for all perturbations does not feature negative energies even in the presence of the Weyl-squared term if the appropriate quantization is performed and this term does not lead to phenomenological problems at least in some relevant setups. The general formulae are applied to a concrete no-scale model, which includes the higgs and a scalar, ``the planckion", whose vacuum expectation value generates the Planck mass. Inflation can be triggered by a combination of the planckion and the Starobinsky scalar leading to a viable scenario. In general, even quadratic inflation is allowed. Moreover, the Weyl-squared term leads to an isocurvature mode, which currently satisfies the observational bounds, but may be detectable with future experiments.

Presentation materials