Related papers: A Walking Dilaton Inflation
Following previous work we further explore the possibility that the chirally broken phase of gauge theories admits an infrared fixed point interpretation. The slope of the $\beta$ function, $\beta'_*$, is found to vanish at the infrared…
We derive expression for the large b_perp asymptotic of the 3D parton distributions q(x,b_perp) in the pion. The asymptotic depends exclusively on the mass scales F_pi and m_pi. Therefore it provides us with a nice example of a strict…
We consider two established supergravities which are known to provide the low-energy effective description of either superstring theory or M-theory: the six-dimensional theory of Romans, and the maximal supergravity in seven dimensions. We…
This talk focuses on the role of light scalars in cosmology, both Nambu Goldstone bosons and pseudo moduli. The former include QCD axions, which might constitute the dark matter, and more general axions, which, under certain conditions,…
In models of natural inflation, the inflaton is an axion-like particle. Unfortunately, axion potentials in UV-complete theories appear to be too steep to drive inflation. We show that, even for a steep potential, natural inflation can occur…
We construct two simple effective field theory versions of {\it Hybrid Natural Inflation (HNI)} that illustrate the range of its phenomenological implications. The resulting inflationary sector potential, $V=\Delta^4(1+a\cos(\phi/f))$,…
We explore a model of a pseudo-Nambu-Goldstone boson inflaton field coupled to a non-Abelian $SU(2)$ gauge field. This model naturally leads to a warm inflation scenario, where the inflationary dynamics is dominated by thermal dissipation.…
A simple realization of inflation consists of adding the following operators to the Einstein-Hilbert action: (partial phi)^2, lambda phi^4, and xi phi^2 R, with xi a large non-minimal coupling. Recently there has been much discussion as to…
The dilaton is investigated from first principles in an asymptotically free Gross-Neveu-Yukawa theory in three dimensions. In the limit of many fermion flavours, the theory features a finite line of strongly interacting fixed points with…
Non-abelian discrete gauge symmetries can provide the inflaton with a flat potential even when one takes into account gravitational strength effects. The discreteness of the symmetries also provide special field values where inflation can…
If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation, requires an axion scale which is greater than…
Techni-dilaton, a pseudo-Nambu-Goldstone boson of scale symmetry, was predicted long ago in the Scale-invariant/Walking/Conformal Technicolor (SWC-TC) as a remnant of the (approximate) scale symmetry associated with the conformal fixed…
The measurement of a large tensor-to-scalar ratio by the BICEP2 experiment, r = 0.20 (-0.05)(+0.07), severely restricts the landscape of viable inflationary models and shifts attention once more towards models featuring large inflaton field…
In this lecture I will review the present status of inflation within string-based brane-world scenarios. The idea is to start from a supersymmetric configuration with two parallel static Dp-branes, and slightly break the supersymmetry…
We study a particular supersymmetric realization of the Peccei-Quinn symmetry which provides a suitable candidate for the curvaton field. The class of models considered also solves the mu problem, while generating the Peccei-Quinn scale…
A pseudo Nambu-Goldstone boson (pNGB) is a natural candidate of dark matter in that it avoids the severe direct detection bounds. We show in this paper that the pNGB has another different and interesting face with a higher symmetry breaking…
We study chaotic inflation in the context of modified gravitational theories. Our analysis covers models based on (i) a field coupling $\omega(\phi)$ with the kinetic energy $X$ and a nonmimimal coupling $\zeta \phi^{2} R/2$ with a Ricci…
We investigate a particular type of curvaton mechanism, under which inflation can occur at Hubble scale of order 1 TeV. The curvaton is a pseudo Nambu-Goldstone boson, whose order parameter increases after a phase transition during…
The minimal warm inflation scenario proposed in Ref. [1] -- featuring an axionlike inflaton coupled to Standard Model (SM) gluons via the standard interaction $\phi G \tilde G$ -- offers a compelling bridge between inflationary dynamics and…
We clarify inflaton models by considering them as effective field theories in the Ginzburg-Landau spirit.In this new approach, the precise form of the inflationary potential is constructed from the present WMAP data, and a useful scheme is…