64 research outputs found
Prethermalisation and the Build Up of the Higgs Effect
Real time field excitations in the broken symmetry phase of the classical
abelian Gauge+Higgs model are studied numerically in the unitary gauge, for
systems starting from the unstable maximum of the Higgs potential.Comment: 5 pages, 6 figures, to appear in proceedings of SEWM'0
Turbulence in nonabelian gauge theory
Kolmogorov wave turbulence plays an important role for the thermalization
process following plasma instabilities in nonabelian gauge theories. We show
that classical-statistical simulations in SU(2) gauge theory indicate a
Kolmogorov scaling exponent known from scalar models. In the range of validity
of resummed perturbation theory this result is shown to agree with analytical
estimates. We study the effect of classical-statistical versus quantum
corrections and demonstrate that the latter lead to the absence of turbulence
in the far ultraviolet.Comment: 13 pages, 4 figures. PLB version, improved statistics indicates
Kolmogorov exponent 4/
Nonequilibrium Goldstone phenomenon in Hybrid Inflation
We study the onset of Goldstone phenomenon in a hybrid inflation scenario.
The physically motivated range of parameters is analyzed in order to meet the
cosmological constraints. Classical equations of motion are solved and the
evolution through the spontaneous symmetry breaking is followed. We emphasize
the role of topological defects that partially maintain the disordered phase
well after the waterfall. We study the emergence of the Goldstone excitations
and their role in the onset of the radiation dominated universe.Comment: 10 pages with 7 figures. Contribution to Strong and Electroweak
Matter (Heidelberg, 2002
Dynamic critical phenomena from spectral functions on the lattice
We investigate spectral functions in the vicinity of the critical temperature
of a second-order phase transition. Since critical phenomena in quantum field
theories are governed by classical dynamics, universal properties can be
computed using real-time lattice simulations. For the example of a relativistic
single-component scalar field theory in 2+1 dimensions, we compute the spectral
function described by universal scaling functions and extract the dynamic
critical exponent z. Together with exactly known static properties of this
theory, we obtain a verification from first principles that the relativistic
theory is well described by the dynamic universality class of relaxational
models with conserved density (Model C).Comment: 18 pages, 6 figures, NPB version, minor change
Complex Langevin dynamics for dynamical QCD at nonzero chemical potential: a comparison with multi-parameter reweighting
We study lattice QCD at non-vanishing chemical potential using the complex
Langevin equation. We compare the results with multi-parameter reweighting both
from and phase quenched ensembles. We find a good agreement for lattice
spacings below 0.15 fm. On coarser lattices the complex Langevin
approach breaks down. Four flavors of staggered fermions are used on
and 8 lattices. For one ensemble we also use two flavors to investigate the
effects of rooting.Comment: 10 pages, 11 figures, PRD version, minor change
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