Sergei V. Ketov

International audience

We find the natural embedding of the ($R+{R}^{2}$) inflationary model into the recently constructed $F(\mathcal{R})$ supergravity. It gives a simple and viable realization of chaotic inflation in supergravity. The only requirement for a slow-roll inflation is the existence of the ${\mathcal{R}}^{3}$ term with an anomalously large coefficient in Taylor expansion of the $F(\mathcal{R})$ function.

Inflationary slow-roll dynamics in Einstein gravity with a non-minimal scalar-curvature coupling can be equivalent to that in the certain f(R) gravity theory. We review the correspondence and extend it to N=1 supergravity. The non-minimal coupling in supergravity is rewritten in terms of the standard (`minimal') N=1 matter-coupled supergravity by using curved superspace. The established equivalence between two different inflationary theories means the same inflaton scalar potential, and does not

Conformal field theory is an elegant and powerful theory in the field of high energy physics and statistics. In fact, it can be said to be one of the greatest achievements in the development of this field. Presented in two dimensions, this book is designed for students who already have a basic knowledge of quantum mechanics, field theory and general relativity. The main idea used throughout the book is that conformal symmetry causes both classical and quantum integrability. Instead of concentrat

A manifestly N=2 supersymmetric completion of the four-dimensional Nambu–Goto–Born–Infeld action, which is self-dual with respect to electric–magnetic duality, is constructed in terms of an Abelian N=2 superfield strength W in the conventional N=2 superspace. A relation to the known N=1 supersymmetric Born–Infeld action in N=1 superspace is established. The action found can be considered either as the Goldstone action associated with a partial breaking of N=4 supersymmetry down to N=2, with the

Abstract We study several extensions of the Starobinsky model of inflation, which obey all observational constraints on the inflationary parameters, by demanding that both the inflaton scalar potential in the Einstein frame and the F ( R ) gravity function in the Jordan frame have the explicit dependence upon fields and parameters in terms of elementary functions. Our models are continuously connected to the original Starobinsky model via changing the parameters. We modify the Starobinsky ( R +

We review the new theory of modified supergravity, dubbed the [Formula: see text] supergravity, and some of its recent applications to inflation and reheating in the early universe cosmology. The [Formula: see text] supergravity is the N = 1 locally supersymmetric extension of the f(R) gravity in four space–time dimensions. A manifestly supersymmetric formulation of the [Formula: see text] supergravity exist in terms of N = 1 superfields, by using the (old) minimal Poincaré supergravity in curve

We propose new supergravity models describing chaotic Linde- and Starobinsky-like inflation in terms of a single chiral superfield. The key ideas to obtain a positive vacuum energy during large field inflation are (i) stabilization of the real or imaginary partner of the inflaton by modifying a Kähler potential, and (ii) use of the crossing terms in the scalar potential originating from a polynomial superpotential. Our inflationary models are constructed by starting from the minimal Kähler poten

We propose a large class of supergravity models in terms of a single chiral matter superfield, leading to (almost) arbitrary single-field inflationary scalar potentials similar to the F-term in rigid supersymmetry. Those scalar potentials are positively semi-definite (in our approximation), and can preserve supersymmetry at the end of inflation. The only scalar superpartner of inflaton is stabilized by a higher-dimensional term in the Kähler potential. We argue that couplings of the inflaton to

The lack of positive results in searches for supersymmetric (SUSY) particles at the Large Hadron Collider (LHC) and in direct searches for Weakly Interacting Massive Particles (WIMPs) in the underground experiments may hint to a super-high energy scale of SUSY phenomena beyond the reach of direct experimental probes. At such scales the supergravity models based on Starobinsky inflation can provide the mechanisms for both inflation and superheavy dark matter. However, it makes the indirect method

We study inflation and preheating in $F(\mathcal{R})$ supergravity characterized by two mass scales of a scalar degree of freedom (scalaron): $M$ (associated with the inflationary era) and $m$ (associated with the preheating era). The allowed values of the masses $M$ and $m$ are derived from the amplitude of the cosmic microwave background temperature anisotropies. We show that our model is consistent with the joint observational constraints of WMAP and other measurements in the regime where a s