When the interbrane separation in the compact Randall-Sundrum model is stabilized using the Goldberger-Wise mechanism, a potential is generated for the four-dimensional field, the radion, that encodes this separation. Coherent oscillations of the radion in the early universe will produce an exponential growth in the number of brane particles due to parametric amplification. We describe the cond...

Symmetry restoration processes during the non-equilibrium stage of “preheating” after inflation is studied. It is shown that symmetry restoration is very efficient when the majority of created particles are concentrated at energies much smaller than the temperature T in equilibrium. The strength of symmetry restoration measured in terms of the equivalent temperature can exceed T by many orders ...

Leptogenesis constitues a very simple scenario to achieve the baryon asymmetry that we observe today. It requires only the presence of right handed neutrinos (which arise very naturally in many extensions of the Standard Model) and depends crucially on the mechanism responsible for their production. In particular, when their mass exceeds the inflaton mass (10 GeV in chaotic inflation) only non ...

We discuss the evolution of linear perturbations about a Friedmann– Robertson–Walker background metric, using only the local conservation of energy– momentum. We show that on sufficiently large scales the curvature perturbation on spatial hypersurfaces of uniform-density is constant when the non-adiabatic pressure perturbation is negligible. We clarify the conditions under which super-horizon c...

We investigate how the hierarchical merging of dark matter halos, the radiative cooling of baryons, and the energy feedback from supernovae and active galactic nuclei or quasars combine to govern the amount and the thermal state of the hot plasma pervading groups and clusters of galaxies. We show that, by itself, supernova preheating of the external gas flowing into clusters falls short of expl...

This article reports the off-design performance analysis of a closed-cycle ocean thermal energy conversion (OTEC) system when a solar thermal collector is integrated as an add-on preheater or superheater. Design-point analysis of a simple OTEC system was numerically conducted to generate a gross power of 100 kW, representing a base OTEC system. In order to improve the power output of the OTEC s...

Systems that exhibit pattern formation are typically driven and dissipative. In the early universe, parametric resonance can drive explosive particle production called preheating. The fields that are populated then decay quantum mechanically if their particles are unstable. Thus, during preheating, a driven-dissipative system exists. We have shown previously that pattern formation can occur in ...

We consider the nonlinear dynamics of inflaton fragmentation during and after preheating in the simplest model of chaotic inflation. While the earlier regime of parametric resonant particle production and the later turbulent regime of interacting fields evolving towards equilibrium are well identified and understood, the short intermediate stage of violent nonlinear dynamics remains less explor...

We outline a scenario of galaxy formation in which the gas in galaxy-forming regions was preheated to high entropy by vigorous energy feedback associated with the formation of stars in old ellipticals and bulges and with AGN activity. Such preheating likely occurred at redshifts z ∼ 2 – 3, and can produce the entropy excess observed today in low-mass clusters of galaxies without destroying the ...

After a short review of inlationary preheating, we discuss the development of equilibrium in the frameworks of massless λΦ model. It is shown that the process is characterised by the appearance of Kolmogorov spectra and the evolution towards thermal equilibrium follows self-similar dynamics. Simplified kinetic theory gives values for all characteristic exponents which are close to what is obser...