3 research outputs found
Computation of the Vortex Free Energy in SU(2) Gauge Theory
We present the first measurement of the vortex free-energy order parameter at
weak coupling for SU(2) in simulations employing multihistogram methods. The
result shows that the excitation probability for a sufficiently thick vortex in
the vacuum tends to unity. This is rigorously known to provide a necessary and
sufficient condition for maintaining confinement at weak coupling in SU(N)
gauge theories.Comment: 7 pages, LaTeX with 3 eps figures, minor changes, replacement of Fig.
A Planck-scale axion and SU(2) Yang-Mills dynamics: Present acceleration and the fate of the photon
From the time of CMB decoupling onwards we investigate cosmological evolution
subject to a strongly interacting SU(2) gauge theory of Yang-Mills scale
eV (masquerading as the factor of the SM at
present). The viability of this postulate is discussed in view of cosmological
and (astro)particle physics bounds. The gauge theory is coupled to a spatially
homogeneous and ultra-light (Planck-scale) axion field. As first pointed out by
Frieman et al., such an axion is a viable candidate for quintessence, i.e.
dynamical dark energy, being associated with today's cosmological acceleration.
A prediction of an upper limit for the duration of the
epoch stretching from the present to the point where the photon starts to be
Meissner massive is obtained: billion years.Comment: v3: consequences of an error in evolution equation for coupling
rectified, only a minimal change in physics results, two refs. adde
Nonperturbative approach to Yang-Mills thermodynamics
An analytical and nonperturbative approach to SU(2) and SU(3) Yang-Mills
thermodynamics is developed and applied. Each theory comes in three phases: A
deconfining, a preconfining, and a confining one. We show how macroscopic and
inert scalar fields form in each phase and how they determine the ground-state
physics and the properties of the excitations. While the excitations in the
deconfining and preconfining phase are massless or massive gauge modes the
excitations in the confining phase are massless or massive spin-1/2 fermions.
The nature of the two phase transitions is investigated for each theory. We
compute the temperature evolution of thermodynamical quantities in the
deconfining and preconfining phase and estimate the density of states in the
confining phase. Some implications for particle physics and cosmology are
discussed.Comment: 92 pages, 35 figures, v4: more typos corrected, modification in
evolution equations for effective couplings, consequences thereof
implemented, there will be an erratum to the journal-published versio