Small field polynomial inflation: reheating, radiative stability and lower bound

Brane inflation and reheating

We study inflation and reheating in a brane world model derived from Type IIA string theory. This particular setup is based on a model of string mediated supersymmetry breaking. The inflaton is one of the transverse scalars of a D4-brane which has one of its spatial dimensions stretched between two NS5-branes, so that it is effectively three-dimensional. This D4-brane is attracted to a D6-brane...

Universe reheating after inflation.

We study the problem of scalar particle production after inflation by an in-flaton field which is oscillating rapidly relative to the expansion of the universe. We use the framework of the chaotic inflation scenario with quartic and quadratic inflaton potentials. Particles produced are described by a quantum scalar field χ, which is coupled to the inflaton via linear and quadratic couplings. Th...

Reheating after inflation.

The theory of reheating of the Universe after inflation is developed. We have found that typically at the first stage of reheating the classical inflaton field φ rapidly decays into φ-particles or into other bosons due to a broad parametric resonance. Then these bosons decay into other particles, which eventually become thermalized. Complete reheating is possible only in those theories where a ...

Mechanisms of Reheating after Inflation

Optimal Complexity Lower Bound for Polynomial Multiplication

We prove lower bounds of order n logn for both the problem of multiplying polynomials of degree n, and of dividing polynomials with remainder, in the model of bounded coefficient arithmetic circuits over the complex numbers. These lower bounds are optimal up to order of magnitude. The proof uses a recent idea of R. Raz [Proc. 34th STOC 2002] proposed for matrix multiplication. It reduces the li...