1,467 research outputs found
Some universal features of the effective string picture of pure gauge theories
The effective string describing the large distance behaviour of the quark
sources of gauge field theories in the confining phase in D=3 or D=4 space-time
dimensions can be formulated, in the infrared limit, as a suitable 2D conformal
field theory on surfaces with quark loops as boundaries. Recent results on
self-avoiding random surfaces allow to fix almost uniquely such a conformal
theory. As a consequence, some universal relationships among the string tension
, the thickness of the colour flux tube, the deconfinement temperature and a
lower bound of the glueball mass spectrum are found. The general agreement with
the data extracted from recent lattice simulations with different gauge groups
is rather impressive.(Talk held by F.Gliozzi at Lattice'92 , Amsterdam)Comment: 9 pages(LaTeX),DFTT61/9
Universal behaviour of interfaces in 2d and dimensional reduction of Nambu-Goto strings
We propose a simple effective model for the description of interfaces in 2d
statistical models, based on the first-order treatment of an action
corresponding to the length of the interface. The universal prediction of this
model for the interface free energy agrees with the result of an exact
calculation in the case of the 2d Ising model. This model appears as a
dimensional reduction of the Nambu-Goto stringy description of interfaces in
3d, i.e., of the capillary wave model.Comment: 14 pages, 1 figur
String effects in SU(2) lattice gauge theory
We discuss the effective string picture for the confining regime of lattice
gauge theories at zero and finite temperature. We present results of extensive
Monte Carlo simulations - performed with the Luscher and Weisz algorithm - for
SU(2) Yang-Mills theory in 2+1 dimensions. We also address the issue of "string
universality" by comparing our results with those obtained in other lattice
gauge theories.Comment: 3 pages, 2 figures, Lattice2003(topology
On the linear increase of the flux tube thickness near the deconfinement transition
We study the flux tube thickness of a generic Lattice Gauge Theory near the
deconfining phase transition. It is well known that the effective string model
predicts a logarithmic increase of the flux tube thickness as a function of the
interquark distance for any confining LGT at zero temperature. It is perhaps
less known that this same model predicts a linear increase in the vicinity of
the deconfinement transition. We present a precise derivation of this result
and compare it with a set of high precision simulations in the case of the 3d
gauge Ising model.Comment: 20 pages, 4 figures, minor changes. Accepted for publication in JHE
Fluid Interfaces in the 3D Ising Model as a Dilute Gas of Handles
We study the topology of fluid interfaces in the 3D Ising model in the rough
phase. It turns out that such interfaces are accurately described as dilute
gases of microscopic handles, and the stiffness of the interface increases with
the genus. The number of configurations of genus follows a Poisson-like
distribution. The probability per unit area for creating a handle is well
fitted in a wide range of the inverse temperature near the roughening
point by an exponentially decreasing function of . The procedure of
summing over all topologies results in an effective interface whose squared
width scales logarithmically with the lattice size.Comment: 15 pages, Latex and 10 ps figs (uuencoded file) DFTT 27/9
A new universality class describing the insulating regime of disordered wires with strong spin-orbit scattering
We discuss the distribution of transmission eigenvalues in the strongly
localized regime in the presence of both a magnetic field and spin--orbit
scattering. We show that, under suitable conditions, this distribution can be
described by a new universality class labelled not only by the index
but also by a new index . This result is obtained by mapping the problem
into that of a suitable Calogero-Sutherland model.Comment: 4 pages, Revte
Corrections to Scaling and Critical Amplitudes in SU(2) Lattice Gauge Theory
We calculate the critical amplitudes of the Polyakov loop and its
susceptibility at the deconfinement transition of SU(2) gauge theory. To this
end we carefully study the corrections to the scaling functions of the
observables coming from irrelevant exponents. As a guiding line for determining
the critical amplitudes we use envelope equations derived from the finite size
scaling formulae for the observables. The equations are then evaluated with new
high precision data obtained on N^3 x 4 lattices for N=12,18,26 and 36. We find
different correction-to-scaling behaviours above and below the transition. Our
result for the universal ratio of the susceptibility amplitudes is
C_+/C_-=4.72(11) and agrees perfectly with a recent measurement for the 3d
Ising model.Comment: LATTICE98(hightemp
Static quark potential and effective string corrections in the (2+1)-d SU(2) Yang-Mills theory
We report on a very accurate measurement of the static quark potential in
SU(2) Yang-Mills theory in (2+1) dimensions in order to study the corrections
to the linear behaviour. We perform numerical simulations at zero and finite
temperature comparing our results with the corrections given by the effective
string picture in these two regimes. We also check for universal features
discussing our results together with those recently published for the (2+1)-d
Z(2) and SU(3) pure gauge theories.Comment: 29 pages, 6 figure
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