Spacetime Curvature and the Higgs Stability During Inflation

158

136

Theories where the Planck scale is dynamically generated from dimensionless interactions provide predictive inflationary potentials and super-Planckian field variations. We first study the minimal single field realisation in the low-energy effective field theory limit, finding the predictions n s ≈ 0.96 for the spectral index and r ≈ 0.13 for the tensor-toscalar ratio, which can be reduced down to ≈ 0.04 in presence of large couplings. Next we consider agravity as a dimensionless quantum gravity theory finding a multifield inflation that converges towards an attractor trajectory and predicts n s ≈ 0.96 and 0.003 < r < 0.13, 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.

Section: The Minimal Model For Dimensionless Single Field Inflationmentioning

confidence: 99%

Dynamically induced Planck scale and inflation

Kannike

Hütsi

Pizza

et al. 2015

158

136

“…In [7,8] the instability of the electroweak vacuum was investigated from a cosmological perspective (see also [9][10][11][12][13][14][15][16]). The main emphasis of [8] was put on the computation of quantum fluctuations of the Higgs field during inflation.…”

Section: Jhep05(2016)050mentioning

confidence: 99%

On the fate of the Standard Model at finite temperature

Rose

Marzo

Urbano

2016

In this paper we revisit and update the computation of thermal corrections to the stability of the electroweak vacuum in the Standard Model. At zero temperature, we make use of the full two-loop effective potential, improved by three-loop beta functions with two-loop matching conditions. At finite temperature, we include one-loop thermal corrections together with resummation of daisy diagrams. We solve numerically -both at zero and finite temperature -the bounce equation, thus providing an accurate description of the thermal tunneling. Assuming a maximum temperature in the early Universe of the order of 10 18 GeV, we find that the instability bound excludes values of the top mass M t 173.6 GeV, with M h 125 GeV and including uncertainties on the strong coupling. We discuss the validity and temperature-dependence of this bound in the early Universe, with a special focus on the reheating phase after inflation.

“…The Higgs field can fluctuate towards values a few orders of magnitude below the Planck scale, for which its potential can be deeper than for the electroweak vacuum [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. If vacuum decay happens during inflation, the regions of true vacuum expand and engulf the whole space [2,18,24].…”

Section: Introductionmentioning

confidence: 99%

(Higgs) vacuum decay during inflation

Joti

Katsis

Loupas

et al. 2017

We develop the formalism for computing gravitational corrections to vacuum decay from de Sitter space as a sub-Planckian perturbative expansion. Non-minimal coupling to gravity can be encoded in an effective potential. The Coleman bounce continuously deforms into the Hawking-Moss bounce, until they coincide for a critical value of the Hubble constant. As an application, we reconsider the decay of the electroweak Higgs vacuum during inflation. Our vacuum decay computation reproduces and improves bounds on the maximal inflationary Hubble scale previously computed through statistical techniques.