Power-counting and the validity of the classical approximation during inflation

By C. Burgess, H. Lee, Michael Trott. 2009

421 citations recorded by the source corpus.

We use the power-counting formalism of effective field theory to study the size of loop corrections in theories of slow-roll inflation, with the aim of more precisely identifying the limits of validity of the usual classical inflationary treatments. We keep our analysis as general as possible in order to systematically identify the most important corrections to the classical inflaton dynamics. Although most slow-roll models lie within the semiclassical domain, we find the consistency of the Higgs-Inflaton scenario to be more delicate due to the proximity between the Hubble scale during inflation and the upper bound allowed by unitarity on the new-physics scale associated with the breakdown of the semiclassical approximation within the effective theory. Similar remarks apply to curvature-squared inflationary models.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/82a24da6550089a0a3a831eb423651f2acb9fdb0

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Citations in the corpus

Higgs boson mass and new physics (2012, background): “One must note, that simple scale analysis leads to the unitarity violation in the Higgs inflation below the Planck energy scale [56–59].”
Inflation with non-minimal gravitational couplings in supergravity (2009, background): “On the one hand, there are some [6, 7] who argue that, as an effective field theory, the full action eq.”
Standard Model—axion—seesaw—Higgs portal inflation. Five problems of particle physics and cosmology solved in one stroke (2016, background): “However, such a large value of ξH implies that perturbative unitarity breaks down below the scale of inflation [11, 12], making the inflationary predictions unreliable.”
Higgs inflation with loop corrections in the Palatini formulation (2017, background): “It has been claimed that the large non-minimal coupling ξ lowers the scale of perturbative violation of unitarity from the Planck scale down to the energy ∼ MPl/ξ [43, 65, 66].5 However, it has been countered that the cutoff scale should depend on the Higgs field [33, 49], and when this is taken int”
The landscape of QCD axion models (2020, methodology): “Having the inflaton direction as a mixture of the radial modes of H and Φ provides a solution of the unitarity problem of standard Higgs inflation [662, 663].”
Stabilization of the electroweak vacuum by a scalar threshold effect (2012, background): “However, due to the same large non-minimal coupling, the unitarity cutoff [47–50] becomes ΛSM = MPl/ξ which is not only much lower than the Planck scale but also lower than the field scales at which the inflationary plateau develops.”