# EPS HEP 2015

22-29 July 2015
Europe/Vienna timezone

## Dynamically Induced Planck Scale and Inflation

Jul 23, 2015, 5:15 PM
15m
HS33

### HS33

talk Astroparticle Physics, Cosmology, Gravitation

### Speaker

Kristjan Kannike (Nat. Inst. of Chem.Phys. & Biophys. (EE))

### Description

We present a minimal model of inflation where the Planck scale is dynamically generated from dimensionless interactions. The inflaton field $\phi$ gets a vacuum expectation value via dimensional transmutation. The Planck scale is generated via its non-minimal coupling to gravity $\xi\phi^2 R$. To generate the minimum of the inflaton potential, one needs a singlet scalar and new fermion(s) which can provide a dark matter candidate. The spectral index is predicted to be $n_s \approx 0.96$. The tensor-to-scalar ratio can vary from $r \approx 0.13$ down to $r \approx 0.04$ in presence of large couplings or $r \approx 0.003$ if the Lagrangian contains an $R^2$ term, interpolating between the quadratic and Starobinsky inflation. These theories relate the smallness of the weak scale to the smallness of inflationary perturbations: both arise naturally because of small couplings, implying a reheating temperature of $10^{7-9}$ GeV. A measurement of $r$ by Keck/Bicep3 would give us information on quantum gravity in the dimensionless scenario.

### Primary author

Kristjan Kannike (Nat. Inst. of Chem.Phys. & Biophys. (EE))

### Co-authors

Alberto Salvio (IFAE, Barcelona) Alessandro Strumia (Nat. Inst. of Chem.Phys. & Biophys. (EE)) Antonio Racioppi (Nat. Inst. of Chem.Phys. & Biophys. (EE)) Dr Gert Hütsi (Tõravere Observatory, Estonia) Mr Liberato Pizza (Pisa University) Dr Martti Raidal (Nat. Inst. of Chem.Phys. & Biophys. (EE))