29 research outputs found
Calorons, Nahm's equations on S^1 and bundles over P^1xP^1
The moduli space of solutions to Nahm's equations of rank (k,k+j) on the
circle, and hence, of SU(2) calorons of charge (k,j), is shown to be equivalent
to the moduli of holomorphic rank 2 bundles on P^1xP^1 trivialized at infinity
with c_2=k and equipped with a flag of degree j along P^1x{0}. An explicit
matrix description of these spaces is given by a monad constructio
QCD Chiral restoration at finite under the Magnetic field: Studies based on the instanton vacuum model
We investigate the chiral restoration at finite temperature under the
strong external magnetic field of the SU(2) light-flavor
QCD matter. We employ the instanton-liquid QCD vacuum configuration accompanied
with the linear Schwinger method for inducing the magnetic field. The
Harrington-Shepard caloron solution is used to modify the instanton parameters,
i.e. the average instanton size and inter-instanton distance
, as functions of . In addition, we include the meson-loop
corrections (MLC) as the large- corrections because they are critical
for reproducing the universal chiral restoration pattern. We present the
numerical results for the constituent-quark mass as well as chiral condensate
which signal the spontaneous breakdown of chiral-symmetry (SBS), as
functions of and . Besides we find that the changes for the and
due to the magnetic field is relatively small, in comparison to those
caused by the finite effect.Comment: 4 pages, 1 table, 6figs. arXiv admin note: significant text overlap
with arXiv:1103.605
On the stability of Dirac sheet configurations
Using cooling for SU(2) lattice configurations, purely Abelian constant
magnetic field configurations were left over after the annihilation of
constituents that formed metastable Q=0 configurations. These so-called Dirac
sheet configurations were found to be stable if emerging from the confined
phase, close to the deconfinement phase transition, provided their Polyakov
loop was sufficiently non-trivial. Here we show how this is related to the
notion of marginal stability of the appropriate constant magnetic field
configurations. We find a perfect agreement between the analytic prediction for
the dependence of stability on the value of the Polyakov loop (the holonomy) in
a finite volume and the numerical results studied on a finite lattice in the
context of the Dirac sheet configurations
Thermodynamic gauge-theory cascade
It is proposed that the cooling of a thermalized SU() gauge theory can be
formulated in terms of a cascade involving three effective theories with
successively reduced (and spontaneously broken) gauge symmetries, SU()
U(1) Z. The approach is based on the assumption that away
from a phase transition the bulk of the quantum interaction inherent to the
system is implicitly encoded in the (incomplete) classical dynamics of a
collective part made of low-energy condensed degrees of freedom. The properties
of (some of the) statistically fluctuating fields are determined by these
condensate(s). This leads to a quasi-particle description at tree-level. It
appears that radiative corrections, which are sizable at large gauge coupling,
do not change the tree-level picture qualitatively. The thermodynamic
self-consistency of the quasi-particle approach implies nonperturbative
evolution equations for the associated masses. The temperature dependence of
these masses, in turn, determine the evolution of the gauge coupling(s). The
hot gauge system approaches the behavior of an ideal gas of massless gluons at
asymptotically large temperature. A negative equation of state is possible at a
stage where the system is about to settle into the phase of the (spontaneously
broken) Z symmetry.Comment: 25 pages, 6 figures, 1 reference added, minor corrections in text,
errors in Sec. 3.2 corrected, PRD versio
Hyperbolic calorons, monopoles, and instantons
We construct families of SO(3)-symmetric charge 1 instantons and calorons on
the space H^3 x R. We show how the calorons include instantons and hyperbolic
monopoles as limiting cases. We show how Euclidean calorons are the flat space
limit of this family.Comment: 11 pages, no figures 1 reference added Published version available
at: http://www.springerlink.com/content/k0j4815u54303450
SU(2) Calorons and Magnetic Monopoles
We investigate the self-dual Yang-Mills gauge configurations on when the gauge symmetry SU(2) is broken to U(1) by the Wilson loop. We
construct the explicit field configuration for a single instanton by the Nahm
method and show that an instanton is composed of two self-dual monopoles of
opposite magnetic charge. We normalize the moduli space metric of an instanton
and study various limits of the field configuration and its moduli space
metric.Comment: 17 pages, RevTex, 1 Figur
ADHM/Nahm Construction of Localized Solitons in Noncommutative Gauge Theories
We study the relationship between ADHM/Nahm construction and ``solution
generating technique'' of BPS solitons in noncommutative gauge theories.
ADHM/Nahm construction and ``solution generating technique'' are the most
strong ways to construct exact BPS solitons. Localized solitons are the
solitons which are generated by the ``solution generating technique.'' The
shift operators which play crucial roles in ``solution generating technique''
naturally appear in ADHM/Nahm construction and we can construct various exact
localized solitons including new solitons: localized periodic instantons
(=localized calorons) and localized doubly-periodic instantons. Nahm
construction also gives rise to BPS fluxons straightforwardly from the
appropriate input Nahm data which is expected from the D-brane picture of BPS
fluxons. We also show that the Fourier-transformed soliton of the localized
caloron in the zero-period limit exactly coincides with the BPS fluxon.Comment: 30 pages, LaTeX, 3 figures; v3: minor changes, references added; v4:
references added, version to appear in PR
Covariant derivative expansion of Yang-Mills effective action at high temperatures
Integrating out fast varying quantum fluctuations about Yang--Mills fields
A_i and A_4, we arrive at the effective action for those fields at high
temperatures. Assuming that the fields A_i and A_4 are slowly varying but that
the amplitude of A_4 is arbitrary, we find a non-trivial effective gauge
invariant action both in the electric and magnetic sectors. Our results can be
used for studying correlation functions at high temperatures beyond the
dimensional reduction approximation, as well as for estimating quantum weights
of classical static configurations such as dyons.Comment: Minor changes. References added. Paper accepted for publication in
Phys.Rev.
Elevated monocyte-specific type I interferon signalling correlates positively with cardiac healing in myocardial infarct patients but interferon alpha application deteriorates myocardial healing in rats
Monocytes are involved in adverse left ventricular (LV) remodelling following myocardial infarction (MI). To provid