scholarly journals Large N scaling and factorization in SU(N) Yang-Mills theory

2018 ◽  
Vol 175 ◽  
pp. 11018 ◽  
Author(s):  
Miguel García Vera ◽  
Rainer Sommer
Keyword(s):  
Lattice Spacing ◽  
Continuum Limit ◽  
Finite Lattice ◽  
Gradient Flow ◽  
Scaling Up ◽  
Wilson Loops ◽  
Yang Mills ◽  
Large N ◽  
The Continuum

We present results for Wilson loops smoothed with the Yang-Mills gradient flow and matched through the scale t0. They provide renormalized and precise operators allowing to test the 1/N2 scaling both at finite lattice spacing and in the continuum limit. Our results show an excellent scaling up to 1/N = 1/3. Additionally, we obtain a very precise non-perturbative confirmation of factorization in the large N limit.

scholarly journals Ergodic sampling of the topological charge using the density of states

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Guido Cossu ◽  
David Lancaster ◽  
Biagio Lucini ◽  
Roberto Pellegrini ◽  
Antonio Rago
Keyword(s):  
Density Of States ◽  
Topological Charge ◽  
Lattice Spacing ◽  
Continuum Limit ◽  
Scaling Properties ◽  
Yang Mills ◽  
Autocorrelation Time ◽  
Firm Evidence ◽  
Sizeable Reduction ◽  
The Continuum

AbstractIn lattice calculations, the approach to the continuum limit is hindered by the severe freezing of the topological charge, which prevents ergodic sampling in configuration space. In order to significantly reduce the autocorrelation time of the topological charge, we develop a density of states approach with a smooth constraint and use it to study SU(3) pure Yang Mills gauge theory near the continuum limit. Our algorithm relies on simulated tempering across a range of couplings, which guarantees the decorrelation of the topological charge and ergodic sampling of topological sectors. Particular emphasis is placed on testing the accuracy, efficiency and scaling properties of the method. In their most conservative interpretation, our results provide firm evidence of a sizeable reduction of the exponent z related to the growth of the autocorrelation time as a function of the inverse lattice spacing.

scholarly journals Effective Action and Measure in Matrix Model of IIB Superstrings

1997 ◽  
Vol 12 (31) ◽  
pp. 2331-2340 ◽  
Author(s):  
L. Chekhov ◽  
K. Zarembo
Keyword(s):  
Matrix Model ◽  
Effective Action ◽  
Continuum Limit ◽  
Auxiliary Field ◽  
Large N ◽  
The Matrix ◽  
Reparametrization Invariance ◽  
The Continuum ◽  
Induced Measure

We calculate an effective action and measure induced by the integration over the auxiliary field in the matrix model recently proposed to describe IIB superstrings. It is shown that the measure of integration over the auxiliary matrix is uniquely determined by locality and reparametrization invariance of the resulting effective action. The large-N limit of the induced measure for string coordinates is discussed in detail. It is found to be ultralocal and, thus, is possibly irrelevant in the continuum limit. The model of the GKM type is considered in relation to the effective action problem.

scholarly journals THE HAGEDORN TRANSITION AND THE MATRIX MODEL FOR STRINGS

1998 ◽  
Vol 13 (26) ◽  
pp. 2085-2094 ◽  
Author(s):  
B. SATHIAPALAN
Keyword(s):  
Matrix Model ◽  
Light Cone ◽  
Degrees Of Freedom ◽  
Low Energy ◽  
Matrix Formalism ◽  
Yang Mills ◽  
Large N ◽  
The Matrix ◽  
The Continuum ◽  
String Worldsheet

We use the matrix formalism to investigate what happens to strings above the Hagedorn temperature. We show that is not a limiting temperature but a temperature at which the continuum string picture breaks down. We study a collection of N D-0-branes arranged to form a string having N units of light-cone momentum. We find that at high temperatures the favored phase is one where the string worldsheet has disappeared and the low-energy degrees of freedom consists of N2 massless particles ("gluons"). The nature of the transition is very similar to the deconfinement transition in large-N Yang–Mills theories.

CHIRALLY EXTENDED QUANTUM CHROMODYNAMICS

1995 ◽  
Vol 06 (05) ◽  
pp. 725-742 ◽  
Author(s):  
RICHARD C. BROWER ◽  
YUE SHEN ◽  
CHUNG-I TAN
Keyword(s):  
Quantum Chromodynamics ◽  
Quark Mass ◽  
Continuum Limit ◽  
Chiral Limit ◽  
Scalar Fields ◽  
Weak Coupling Limit ◽  
Slowing Down ◽  
Large N ◽  
Chiral Invariance ◽  
The Continuum

We propose an extended Quantum Chromodynamics (XQCD) Lagrangian in which the fermions are coupled to elementary scalar fields through a Yukawa coupling which preserves chiral invariance. Our principle motivation is to find a new lattice formulation for QCD which avoids the source of critical slowing down usually encountered as the bare quark mass is tuned to the chiral limit. The phase diagram and the weak coupling limit for XQCD are studied. They suggest a conjecture that the continuum limit of XQCD is the same as the continuum limit of conventional lattice formulation of QCD. As examples of such universality, we present the large N solutions of two prototype models for XQCD, in which the mass of the spurious pion and sigma resonance go to infinity with the cut-off. Even if the universality conjecture turns out to be false, we believe that XQCD will still be useful as a low energy effective action for QCD phenomenology on the lattice. Numerical simulations are recommended to further investigate the possible benefits of XQCD in extracting QCD predictions.

scholarly journals WILSON LOOPS IN 2D YANG-MILLS: EULER CHARACTERS AND LOOP EQUATIONS

1996 ◽  
Vol 11 (21) ◽  
pp. 3885-3933 ◽  
Author(s):  
SANJAYE RAMGOOLAM
Keyword(s):  
Lattice Models ◽  
Symmetric Groups ◽  
Linear Constraints ◽  
Partition Functions ◽  
Wilson Loops ◽  
Dimensional Lattice ◽  
Yang Mills ◽  
Branched Covering ◽  
Large N ◽  
Higher Dimensional

We give a simple diagrammatic algorithm for writing the chiral large N expansion of intersecting Wilson loops in 2D SU(N) and U(N) Yang-Mills theory in terms of symmetric groups, generalizing the result of Gross and Taylor for partition functions. We prove that these expansions compute Euler characters of a space of branched covering maps from string worldsheets with boundaries. We prove that the Migdal-Makeenko equations hold for the chiral theory and show that they can be expressed as linear constraints on perturbations of the chiral YM 2 partition functions. We briefly discuss finite N, the nonchiral expansion, and higher-dimensional lattice models.

scholarly journals A STUDY OF GLUON PROPAGATOR ON COARSE LATTICE

2000 ◽  
Vol 15 (04) ◽  
pp. 229-244 ◽  
Author(s):  
J. P. MA
Keyword(s):  
Lattice Qcd ◽  
Smooth Function ◽  
Qualitative Agreement ◽  
Lattice Spacing ◽  
Continuum Limit ◽  
Gluon Propagator ◽  
Landau Gauge ◽  
Lattice Action ◽  
Lattice Volume ◽  
The Continuum

We study gluon propagator in Landau gauge with lattice QCD, where we use an improved lattice action. The calculation of gluon propagator is performed on lattices with the lattice spacing from 0.40 fm to 0.24 fm and with the lattice volume from (2.40 fm )4 to (4.0 fm )4. We find that the rotation invariance is approximately restored in the q2-range, indicated by the fact that the propagator is a smooth function of the continuum momentum q2. We try to fit our results by two different ways, in the first one we interpret the calculated gluon propagators as a function of the continuum momentum, while in the second we interpret the propagators as a function of the lattice momentum. In both cases we use models which are the same in continuum limit. A qualitative agreement between two fittings is found.

MATRIX REGULARIZATION OF N = 4 SYM ON R × S3

2008 ◽  
Vol 23 (14n15) ◽  
pp. 2199-2200 ◽  
Author(s):  
GORO ISHIKI
Keyword(s):  
Gauge Symmetry ◽  
Plane Wave ◽  
Regularization Method ◽  
Ward Identity ◽  
Continuum Limit ◽  
Beta Function ◽  
Yang Mills ◽  
Planar Limit ◽  
Matrix Regularization ◽  
The Continuum

We revealed a relationship between the plane wave matrix model (PWMM) and N =4 super Yang-Mills (SYM) theory on R × S3: N =4 SYM on R × S3 is equivalent to the theory around a certain vacuum of PWMM. It is suggested from this relation that N =4 SYM on R × S3 is regularized by PWMM in the planar limit. Because PWMM originally possesses the gauge symmetry and SU(2|4) symmetry, this regularization also preserves these symmetries. In order to check the validity of this matrix regularization method, we calculate the Ward identity and the beta function at the 1-loop level. We find that the Ward identity is satisfied and the beta function vanishes in the continuum limit. The former result is consistent with the gauge symmetry of PWMM. The latter suggests the possibility that the conformal symmety is restored in the continuum limit.

scholarly journals ON THE LARGE N LIMIT, WILSON LOOPS, CONFINEMENT AND COMPOSITE ANTISYMMETRIC TENSOR FIELD THEORIES

2004 ◽  
Vol 19 (25) ◽  
pp. 4251-4270 ◽  
Author(s):  
CARLOS CASTRO
Keyword(s):  
Tensor Field ◽  
Degrees Of Freedom ◽  
Vacuum Expectation ◽  
Field Theories ◽  
Antisymmetric Tensor ◽  
Wilson Loops ◽  
Tensor Fields ◽  
Yang Mills ◽  
Large N ◽  
Antisymmetric Tensor Field

A novel approach to evaluate the Wilson loops associated with a SU (∞) gauge theory in terms of pure string degrees of freedom is presented. It is based on the Guendelman–Nissimov–Pacheva formulation of composite antisymmetric tensor field theories of area (volume) preserving diffeomorphisms which admit p-brane solutions and which provide a new route to scale-symmetry breaking and confinement in Yang–Mills theory. The quantum effects are discussed and we evaluate the vacuum expectation values (VEV) of the Wilson loops in the large N limit of the quenched reduced SU (N) Yang–Mills theory in terms of a path integral involving pure string degrees of freedom. The quenched approximation is necessary to avoid a crumpling of the string worldsheet giving rise to very large Hausdorff dimensions as pointed out by Olesen. The approach is also consistent with the recent results based on the AdS/CFT correspondence and dual QCD models (dual Higgs model with dual Dirac strings). More general Loop wave equations in C-spaces (Clifford manifolds) are proposed in terms of generalized holographic variables that contain the dynamics of an aggregate of closed branes (p-loops) of various dimensionalities. This allows us to construct the higher-dimensional version of Wilson loops in terms of antisymmetric tensor fields of arbitrary rank which couple to p-branes of different dimensionality.

scholarly journals Truncation of lattice N = 4 super Yang-Mills

2018 ◽  
Vol 175 ◽  
pp. 11008 ◽  
Author(s):  
Joel Giedt ◽  
Simon Catterall ◽  
Raghav Govind Jha
Keyword(s):  
Gauge Theory ◽  
Gauge Symmetry ◽  
Moduli Space ◽  
Lattice Spacing ◽  
Continuum Limit ◽  
Power Counting ◽  
Yang Mills ◽  
Free Theory ◽  
Lattice Gauge ◽  
Two Sectors

In twisted and orbifold formulations of lattice N = 4 super Yang-Mills, the gauge group is necessarily U(1) × SU(N), in order to be consistent with the exact scalar supersymmetry Q. In the classical continuum limit of the theory, where one expands the link fields around a point in the moduli space and sends the lattice spacing to zero, the diagonal U(1) modes decouple from the SU(N) sector, and give an uninteresting free theory. However, lattice artifacts (described by irrelevant operators according to naive power-counting) couple the two sectors, so removing the U(1) modes is a delicate issue. We describe how this truncation to an SU(N) gauge theory can be obtained in a systematic way, with violations of Q that fall off as powers of 1=N2. We are able to achieve this while retaining exact SU(N) lattice gauge symmetry at all N, and provide both theoretical arguments and numerical evidence for the 1=N2 suppression of Q violation.

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