6,775 research outputs found
High precision Monte Carlo simulations of interfaces in the three-dimensional Ising model: a comparison with the Nambu-Goto effective string model
Motivated by the recent progress in the effective string description of the
interquark potential in lattice gauge theory, we study interfaces with periodic
boundary conditions in the three-dimensional Ising model. Our Monte Carlo
results for the associated free energy are compared with the next-to-leading
order (NLO) approximation of the Nambu-Goto string model. We find clear
evidence for the validity of the effective string model at the level of the NLO
truncation.Comment: 20 pages, 1 figur
Width of the flux tube in compact U(1) gauge theory in three dimensions
We study the squared width and the profile of flux tubes in compact U(1)
lattice gauge theory in three spacetime dimensions. The results obtained from
numerical calculations in the dual formulation of this confining theory are
compared with predictions from an effective bosonic-string model and from the
dual-superconductor model: it is found that the former fails at describing the
quantitative features of the flux tube, while the latter is in good agreement
with Monte Carlo data. The analytical interpretation of these results (in the
light of the semi-classical analysis by Polyakov) is pointed out, and a
comparison with non-Abelian gauge theories in four spacetime dimensions is
discussed.Comment: 19 pages, 5 pdf figures; v2: 21 pages, 8 pdf figures: references
added, new data and new figures included, discussion slightly revise
Effective string description of confining flux tubes
We review the current knowledge about the theoretical foundations of the
effective string theory for confining flux tubes and the comparison of the
predictions to pure gauge lattice data. A concise presentation of the effective
string theory is provided, incorporating recent developments. We summarize the
predictions for the spectrum and the profile/width of the flux tube and their
comparison to lattice data. The review closes with a short summary of open
questions for future research.Comment: 21 pages, 8 figures, Contribution to IJMPA special issue "Lattice
gauge theory beyond QCD
Integrable structures in LGTs near the deconfinement transition
In this contribution we review some recent results about the emergence of 2D
integrable systems in 3D Lattice Gauge Theories near the deconfinement
transition. We focus on some concrete examples involving the flux tube
thickness, the ratio of k-string tensions and Polyakov loops correlators in
various models.Comment: 8 pages, Poster contribution to the XXVII International Symposium on
Lattice Field Theory, July 26-31, 2009, Peking University, Beijing, Chin
The Lorentz-invariant boundary action of the confining string and its universal contribution to the inter-quark potential
We study the boundary contribution to the low energy effective action of the
open string describing the confining flux tube in gauge theories. The form of
the boundary terms is strongly constrained by the requirement of Lorentz
symmetry, which is spontaneously broken by the formation of a long confining
flux tube in the vacuum. Writing the boundary action as an expansion in the
derivatives of the Nambu-Goldstone modes describing the transverse fluctuations
of the string, we single out and put in a closed form the first few Lorentz
invariant boundary terms. We also evaluate the leading deviation from the
Nambu-Goto string produced by the boundary action on the vacuum expectation
value of the Wilson loop and we test this prediction in the 3d Ising gauge
model. Our simulation attains a level of precision which is sufficient to test
the contribution of this term.Comment: 17 pages, 5 figures, LateX 2e. V2: Final version published on JHEP.
Fixed typos in eq.s 2.2, 2.3, 3.7, 3.8, A.4. Extended explanation of the
procedures used in sec 2 to determine the possible boundary terms up to field
redefinitions and of the procedure used in sec 4 to take the continuum limit.
V3: typos corrected in eq.s (4.3) (4.5) and (4.6), acknowledgements adde
Finite temperature behaviour of glueballs in Lattice Gauge Theories
We propose a new method to compute glueball masses in finite temperature
Lattice Gauge Theories which at low temperature is fully compatible with the
known zero temperature results and as the temperature increases leads to a
glueball spectrum which vanishes at the deconfinement transition. We show that
this definition is consistent with the Isgur-Paton model and with the expected
contribution of the glueball spectrum to various thermodynamic quantities at
finite temperature. We test our proposal with a set of high precision numerical
simulations in the 3d gauge Ising model and find a good agreement with our
predictions.Comment: 4 pages, 4 figure
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
Flux tube delocalization at the deconfinement point
We study the behaviour of the flux tube thickness in the vicinity of the
deconfinement transition. We show, using effective string methods, that in this
regime the square width increases linearly and not logarithmically with the
interquark distance. The amplitude of this linear growth is an increasing
function of the temperature and diverges as the deconfinement transition is
approached from below. These predictions are in good agreement with a set of
simulations performed in the 3d gauge Ising model.Comment: 16 pages, 1 figure. Revised version, with an improved discussion of
the dimensional reduction approach. Accepted for publication in JHE
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