We consider a two-field model for inflation where the second order metric perturbations can be amplified by a parametric resonance during preheating. We demonstrate that there can arise a considerable enhancement of non-Gaussianity sourced by the local terms generated through the coupled perturbations. We argue that the non-Gaussianity parameter could be as large as f(NL) approximately 50. Our ...

We establish the equivalence between the quantum evolution of spatially homogeneous oscillations of a scalar field and that of an analogous classical system with certain random initial condition. We argue that this observation can be used for numerical simulation of the Universe in the preheating epoch. We also explicitly demonstrate that the phenomenon of parametric resonance that leads to pre...

Fluctuations of scalar elds produced at the stage of preheating after in ation are so large that they can break supersymmetry much stronger than in ation itself. These uctuations may lead to symmetry restoration along at directions of the e ective potential even in the theories where the usual high temperature corrections are exponentially suppressed. Our results show that nonthermal phase tran...

We consider inhomogeneous preheating in a multi-field trapping model. The curvature perturbation is generated by inhomogeneous preheating which induces multi-field trapping at the enhanced symmetric point (ESP), and results in fluctuation in the number of e-foldings. Instead of considering simple reheating after preheating, we consider a scenario of shoulder inflation induced by the trapping. T...

The time course of change in thermosensitivity of SCK tumor cells in vivo was investigated following preheating at 43.5 degrees for 30 min. At varying times after the preheating with water bath, tumors were subjected to graded doses of second heating at 43.5 degrees in vivo, and cell survival was determined by using in vitro cloning method. Thermosensitivity of the tumor cells in vivo [duration...

The ASTM F-75 (Co-28%Cr-6%Mo) is widely used as a biocompatible alloy in medicinefor manufacturing implants. In this study, effect of mold preheating on the as-cast microstructure of thealloy was investigated using the solid investment casting process. Several mold preheating temperaturesof 550, 700, 850 and 1000 °C were selected at the same melt superheat. The samples were characterizedby opti...

Takashi Torii ‡ Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152, Japan (June 4, 2005) In higher-curvature inflation models (R + αnR ), we study a parametric preheating of a scalar field χ coupled non-minimally to a spacetime curvature R (ξRχ). In the case of R-inflation model, efficient preheating becomes possible for rather small values of ξ, i.e. |ξ|∼ several. Although...

We discuss toy models where supersymmetry is broken due to a nonvanishing time-varying vacuum expectation value of the inflaton field during preheating. We discuss the production of an inflatino, the superpartner of the inflaton, due to vacuum fluctuations and then we argue that they do not survive until nucleosynthesis and decay along with the inflaton to produce a thermal bath after preheatin...