We reconsider the old problem of dynamics spontaneous symmetry breaking (SSB) using 3D lattice simulations. develop a theory tachyonic preheating, which occurs due to spinodal instability scalar field. Tachyonic preheating is so efficient that SSB typically completes within single oscillation as field rolls towards minimum its effective potential. show that, contrary previous expectations, in hybrid inflation tachyonic. Our results may also be relevant for formation topological defects and...

We consider preheating in the theory $1/4 \lambda \phi^4 + 1/2 g^2\phi^2\chi^2 $, where classical oscillating inflaton field $\phi$ decays into $\chi$-particles and $\phi$-particles. The parametric resonance which leads to particle production this conformally invariant is described by Lame equation. It significantly differs from with a quadratic potential. structure of depends rather nontrivial way on parameter $g^2/\lambda$. construct stability/instability chart for arbitrary give simple...

Large scale structure introduces two different kinds of errors in the luminosity distance estimates from standardizable candles such as supernovae Ia (SNe)---a Poissonian scatter for each SN and a coherent component due to correlated fluctuations between SNe. Increasing number SNe helps reduce first type error but not second. The has been largely ignored forecasts dark energy parameter estimation upcoming surveys. For instance it is commonly thought, based on considerations, that peculiar...

In inflationary cosmology, the particles constituting Universe are created after inflation due to their interaction with moving inflaton field(s) in process of preheating. fermionic sector, leading channel is out-of equilibrium particle production non-perturbative regime parametric excitation, which respects Pauli blocking but differs significantly from perturbative expectation. We develop theory preheating coupling inflaton, without and expansion universe, for light massive fermions,...

A variety of observations indicate that the universe is dominated by dark energy with negative pressure, one possibility for which a cosmological constant. If constant, fundamental question is: Why has it become relevant at so late an epoch, making today only time in history constant order ambient density. We explore answer to this drawing on ideas from unimodular gravity, predicts fluctuations and causal set theory, magnitude these fluctuations. The resulting ansatz yields fluctuating...

We present a realistic supergravity inflation model that is free from the overproduction of potentially dangerous relics in cosmology, namely, moduli and gravitinos, which can lead to inconsistencies with predictions baryon asymmetry nucleosynthesis. The radiative correction turns out play crucial role our analysis, raising mass supersymmetry breaking field an intermediate scale. pay particular attention nonthermal production gravitinos using nonminimal K\"ahler potential we obtained loop...

Large scale structure introduces two different kinds of errors in the luminosity distance estimates from standardizable candles such as supernovae Ia (SNe) - a Poissonian scatter for each SN and coherent component due to correlated fluctuations between SNe. Increasing number SNe helps reduce first type error but not second. The has been largely ignored forecasts dark energy parameter estimation upcoming surveys. For instance it is commonly thought, based on considerations, that peculiar...

Coherent oscillations of the inflaton field at end inflation can parametrically excite fermions in much same way that bosons are created preheating. Although Pauli-blocking prohibits occupation number from growing exponentially, fermion production occurs a manner significantly different expectations simple perturbation theory. Here, I discuss nature after and possible applications including efficient transfer energy super-massive during fermionic