3,211 research outputs found
Abelian and center gauges in continuum Yang-Mills-Theory
Abelian and center gauges are considered in continuum Yang-Mills theory in
order to detect the magnetic monopole and center vortex content of gauge field
configurations. Specifically we examine the Laplacian Abelian and center
gauges, which are free of Gribov copies, as well as the center gauge analog of
the (Abelian) Polyakov gauge. In particular, we study meron, instanton and
instanton-anti-instanton field configurations in these gauges and determine
their monopole and vortex content. While a single instanton does not give rise
to a center vortex, we find center vortices for merons. Furthermore we provide
evidence, that merons can be interpreted as intersection points of center
vortices. For the instanton-anti-instanton pair, we find a center vortex
enclosing their centers, which carries two monopole loops.Comment: 31 pages, 9 figures, Latex2e, 2 figures and some references added,
some minor misprints correcte
Color Screening, Casimir Scaling, and Domain Structure in G(2) and SU(N) Gauge Theories
We argue that screening of higher-representation color charges by gluons
implies a domain structure in the vacuum state of non-abelian gauge theories,
with the color magnetic flux in each domain quantized in units corresponding to
the gauge group center. Casimir scaling of string tensions at intermediate
distances results from random spatial variations in the color magnetic flux
within each domain. The exceptional G(2) gauge group is an example rather than
an exception to this picture, although for G(2) there is only one type of
vacuum domain, corresponding to the single element of the gauge group center.
We present some numerical results for G(2) intermediate string tensions and
Polyakov lines, as well as results for certain gauge-dependent projected
quantities. In this context, we discuss critically the idea of projecting link
variables to a subgroup of the gauge group. It is argued that such projections
are useful only when the representation-dependence of the string tension, at
some distance scale, is given by the representation of the subgroup.Comment: 24 pages, 14 figures; v2: references added; v3: published version
containing some additional introductory discussio
Abelian Projection on the Torus for general Gauge Groups
We consider Yang-Mills theories with general gauge groups and twists on the four torus. We find consistent boundary conditions for gauge fields in all instanton sectors. An extended Abelian projection with respect to the Polyakov loop operator is presented, where is independent of time and in the Cartan subalgebra. Fundamental domains for the gauge fixed are constructed for arbitrary gauge groups. In the sectors with non-vanishing instanton number such gauge fixings are necessarily singular. The singularities can be restricted to Dirac strings joining magnetically charged defects. The magnetic charges of these monopoles take their values in the co-root lattice of the gauge group. We relate the magnetic charges of the defects and the windings of suitable Higgs fields about these defects to the instanton number
Uniqueness of infrared asymptotics in Landau gauge Yang-Mills theory
We uniquely determine the infrared asymptotics of Green functions in Landau
gauge Yang-Mills theory. They have to satisfy both,
Dyson-Schwinger equations and functional renormalisation group equations.
Then, consistency fixes the relation between the infrared power laws of these
Green functions. We discuss consequences for the interpretation of recent
results from lattice QCD.Comment: 24 pages, 8 figure
SU(N)-Gauge Theories in Polyakov Gauge on the Torus
We investigate the Abelian projection with respect to the Polyakov loop
operator for SU(N) gauge theories on the four torus. The gauge fixed is
time-independent and diagonal. We construct fundamental domains for . In
sectors with non-vanishing instanton number such gauge fixings are always
singular. The singularities define the positions of magnetically charged
monopoles, strings or walls. These magnetic defects sit on the Gribov horizon
and have quantized magnetic charges. We relate their magnetic charges to the
instanton number.Comment: 11 pages, 2 figure
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