Related papers: The End for Extended Inflation?
An inflationary stage dominated by a D-term avoids the slow-roll problem of inflation in supergravity and can naturally emerge in theories with a non-anomalous or anomalous U(1) gauge symmetry. In the latter case, however, the scale of…
Starting from a gauge invariant treatment of perturbations an analytical expression for the spectrum of long wavelength density perturbations in warm inflation is derived. The adiabatic and entropy modes are exhibited explicitly. As an…
In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…
We investigate Power-Law Plateau (PLP) inflation in standard gravity and its consistency with ACT DR6 data. While many inflationary models, including the Starobinsky inflation, are disfavored by ACT observations, the PLP potential remains…
We explicitly construct a double-field inflationary model, which satisfies the latest Planck constraints at the cosmic microwave background (CMB) scales and produces the whole dark matter energy density as primordial black holes (PBHs), in…
Inflationary theory is already 20 years old, and it is impossible to describe all of its versions and implications in a short talk. I will concentrate on several subjects which I believe to be most important. First of all, I will give a…
Observations of the cosmic microwave sky are revealing the primordial non-uniformities from which all structure in the Universe grew. The only known physical mechanism for generating the inhomogeneities we see involves the amplification of…
We examine the possibility that Universe expansion be made of some $\Lambda CDM$ expansions repeating periodically, separated by some inflation and radiation dominated phases. This so-called $\Lambda CDM$ periodic cosmology is motivated by…
We study a simple extension of Linde's hybrid inflation model, with the inflaton mass term replaced by the most general renormalizable potential for $\phi$. The unprocessed power spectrum of density perturbations can have two minima and one…
We reconsider the enhancement of primordial gravitational waves that arises from a quantum gravitational model of inflation. A distinctive feature of this model is that the end of inflation witnesses a brief phase during which the Hubble…
The recent observations from CMB have imposed a very stringent upper-limit on the tensor/scalar ratio $r$ of inflation models, $r < 0.064$, which indicates that the primordial gravitational waves (PGW), even though possible to be detected,…
It is presumed that thermal fluctuations present during inflationary epoch can make inflaton scalar field to interact with other fields resulting in the existence of a thermal component during the inflationary period. The presence of this…
We study the observational predictions of the phenomenological anti-de Sitter (AdS)/QCD inspired model, in which the inflaton field emerges in a four-dimensional strongly coupled gauge theory, in which the chiral symmetry breaking occurs…
The influence of higher-order terms in the K\"{a}hler potential of the supergravity D-term inflation model on the density perturbation is studied. We show that these terms can make the inflaton potential flatter, which lowers the energy…
The basic workings of inflationary models are summarized, along with the arguments that strongly suggest that our universe is the product of inflation. I describe the quantum origin of density perturbations, giving a heuristic derivation of…
Recently Hollands and Wald argued that inflation does not solve any of the major cosmological problems. We explain why we disagree with their arguments. They also proposed a new speculative mechanism of generation of density perturbations.…
The 2015 Planck data release tightened the region of the allowed inflationary models. Inflationary models with convex potentials have now been ruled out since they produce a large tensor to scalar ratio. Meanwhile the same data offers…
In numerical calculations of the primordial power spectrum of perturbations produced during inflation, for very little wavenumber $k$s, to implement the initial conditions required of the perturbation mode functions consistently, we must…
We develop general criteria to construct unified frameworks for inflation and quintessence which employ a unique scalar field to drive both. By using such a minimal theoretical framework we avoid having to fine-tune couplings and…
It has been shown that sub-Planckian models of inflation require initial homogeneity on super-Hubble scales under certain commonly held assumptions. Here I remark on the possible implications of this result for inflationary cosmology.