3,681 research outputs found
Vector order parameter in general relativity. Covariant equations
Phase transitions with spontaneous symmetry breaking and vector order
parameter are considered in multidimensional theory of general relativity.
Covariant equations, describing the gravitational properties of topological
defects, are derived. The topological defects are classified in accordance with
the symmetry of the covariant derivative of the vector order parameter. The
abilities of the derived equations are demonstrated in application to the brane
world concept. New solutions of the Einstein equations with a transverse vector
order parameter are presented. In the vicinity of phase transition the
solutions are found analytically
On the azimuthal asymmetries in DIS
Using the recent experimental data on the left right asymmetry in
fragmentation of transversely polarized quarks and the theoretical calculation
of the proton transversity distribution in the effective chiral quark soliton
model we explain the azimuthal asymmetries in semi-inclusive hadron production
on longitudinal (HERMES) and transversely (SMC) polarized targets with no free
parameters. On this basis we state that the proton transversity distribution
could be successfully measured in future DIS experiments with longitudinally
polarized target.Comment: 8 pages, latex, 5 eps figures, uses epsfig and wrapfi
Field equations and vector order parameter in braneworld applications
Phase transitions with spontaneous symmetry breaking and vector order
parameter are considered in multidimensional theory of general relativity.
Covariant equations, describing the gravitational properties of topological
defects, are derived. The topological defects are classified in accordance with
the symmetry of the covariant derivative of the vector order parameter. The
abilities of the derived equations are demonstrated in application to the brane
world concept. New solutions of the Einstein equations with a transverse vector
order parameter are presented. In the vicinity of phase transition the
solutions are found analytically. Comparison with the commonly used scalar
multiplet approach demonstrates the advantages of the vector order parameter.Comment: Text of the plenary report by B.E.Meierovich at the International
Conference "Modern problems of gravitation, cosmology, and relativistic
astrophysics", Moscow, June 27 -- July 3, 2010 (RUDN-10
Phases of bosonic strings and two dimensional gauge theories
We suggest that the extrinsic curvature and torsion of a bosonic string can
be employed as variables in a two dimensional Landau-Ginzburg gauge field
theory. Their interpretation in terms of the abelian Higgs multiplet leads to
two different phases. In the phase with unbroken gauge symmetry the ground
state describes open strings while in the phase with broken gauge symmetry the
ground state involves closed strings. When we allow for an additional abelian
gauge structure along the string, we arrive at an interpretation in terms of
the two dimensional SU(2) Yang-Mills theory.Comment: 8 page
Anomaly matching for the QCD string
A criterion to be satisfied by a string theory of QCD is formulated in the
ultraviolet regime. It arises from the trace anomaly of the QCD stress tensor
computed using instantons. It is sensitive to asymptotic freedom. It appears to
be related to the trace anomaly of the QCD string. Our current understanding of
noncritical strings in physical dimensions is limited, but remarkably, a formal
treatment of the bosonic string yields numerical agreement both in magnitude
and sign for the gauge group SU(2).Comment: Latex file, 8 pages, COLO-HEP/313, AZPH-TH/93-1
Helicity skewed quark distributions of the nucleon and chiral symmetry
We compute the helicity skewed quark distributions and
in the chiral quark-soliton model of the nucleon. This model
emphasizes correctly the role of spontaneously broken chiral symmetry in
structure of nucleon. It is based on the large-N_c picture of the nucleon as a
soliton of the effective chiral lagrangian and allows to calculate the leading
twist quark- and antiquark distributions at a low normalization point. We
discuss the role of chiral symmetry in the helicity skewed quark distributions
and . We show that generalization of soft pion
theorems, based on chiral Ward identities, leads in the region of -\xi < x <
\xi to the pion pole contribution to which dominates at small
momentum transfer.Comment: 22 pages, 5 figure
Loop expansion in Yang-Mills thermodynamics
We argue that a selfconsistent spatial coarse-graining, which involves
interacting (anti)calorons of unit topological charge modulus, implies that
real-time loop expansions of thermodynamical quantities in the deconfining
phase of SU(2) and SU(3) Yang-Mills thermodynamics are, modulo 1PI
resummations, determined by a finite number of connected bubble diagrams.Comment: 15 pages, 2 figures, v5: discussion of much more severely constrained
nonplanar situation included in Sec.
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