scholarly journals QCD AND STRING THEORY

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1831-1843 ◽  
Author(s):  
IGOR R. KLEBANOV
Keyword(s):  
Gauge Theory ◽  
String Theory ◽  
Compact Manifold ◽  
Gauge Theories ◽  
Density Ratio ◽  
Entropy Density ◽  
Strong Interactions ◽  
De Sitter ◽  
Strongly Coupled ◽  
Basic Facts

This talk begins with some history and basic facts about string theory and its connections with strong interactions. Comparisons of stacks of Dirichlet branes with curved backgrounds produced by them are used to motivate the AdS/CFT correspondence between superconformal gauge theory and string theory on a product of Anti-de Sitter space and a compact manifold. The ensuing duality between semi-classical spinning strings and long gauge theory operators is briefly reviewed. Strongly coupled thermal SYM theory is explored via a black hole in 5-dimensional AdS space, which leads to explicit results for its entropy and shear viscosity. A conjectured universal lower bound on the viscosity to entropy density ratio, and its possible relation to recent results from RHIC, are discussed. Finally, some available results on string duals of confining gauge theories are briefly reviewed.

scholarly journals META-STABLE BRANE CONFIGURATIONS WITH MULTIPLE NS5-BRANES

2009 ◽  
Vol 24 (27) ◽  
pp. 5051-5120
Author(s):  
CHANGHYUN AHN
Keyword(s):  
Gauge Theory ◽  
String Theory ◽  
Gauge Group ◽  
Gauge Theories ◽  
The Other ◽  
Multiple Product

Starting from an [Formula: see text] supersymmetric electric gauge theory with the multiple product gauge group and the bifundamentals, we apply Seiberg dual to each gauge group, obtain the [Formula: see text] supersymmetric dual magnetic gauge theories with dual matters including the gauge singlets. Then we describe the intersecting brane configurations, where there are NS-branes and D4-branes (and anti-D4-branes), of type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua of this gauge theory. We also discuss the case where the orientifold 4-planes are added into the above brane configuration. Next, by adding an orientifold 6-plane, we apply to an [Formula: see text] supersymmetric electric gauge theory with the multiple product gauge group (where a single symplectic or orthogonal gauge group is present) and the bifundamentals. Finally, we describe the other cases where the orientifold 6-plane intersects with NS-brane.

scholarly journals Higgsing towards E-strings

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Joonho Kim ◽  
Seok Kim ◽  
Kimyeong Lee
Keyword(s):  
String Theory ◽  
Gauge Theories ◽  
The Self ◽  
Flavor Symmetry ◽  
Strongly Coupled ◽  
Superconformal Field Theories ◽  
Yang Mills ◽  
Gauge Symmetries ◽  
Elliptic Genera ◽  
Linear Sigma Models

Abstract We explore 6d (1, 0) superconformal field theories with SU(3) and SU(2) gauge symmetries which cascade after Higgsing to the E-string theory on a single M5 near an E8 wall. Specifically, we study the 2d $$ \mathcal{N} $$ N = (0, 4) gauge theories which describe self-dual strings of these 6d theories. The self-dual strings can be also viewed as instanton string solitons of 6d Yang-Mills theories. We find the 2d anomaly-free gauge theories for self-dual strings, amending the naive ADHM gauge theories which are anomalous, and calculate their elliptic genera. While these 2d theories respect the flavor symmetry of each 6d SCFT only partially, their elliptic genera manifest the symmetry fully as these functions as BPS index are invariant in strongly coupled IR limit. Our consistent 2d (0, 4) gauge theories also provide new insights on the non-linear sigma models for the instanton strings, providing novel UV completions of the small instanton singularities. Finally, we construct new 2d quiver gauge theories for the self-dual strings in 6d E-string theory for multiple M5-branes probing the E8 wall, and find their fully refined elliptic genera.

scholarly journals GRAVITATION, THERMODYNAMICS, AND THE BOUND ON VISCOSITY

2009 ◽  
Vol 18 (14) ◽  
pp. 2337-2341
Author(s):  
SHAHAR HOD
Keyword(s):  
Field Theory ◽  
Gauge Theories ◽  
Entropy Density ◽  
De Sitter ◽  
Small Perturbations ◽  
General Validity ◽  
Small Deviations ◽  
Conformal Field ◽  
Direct Outcome ◽  
Recent Attention

The anti-de Sitter/conformal field theory (AdS/CFT) correspondence implies that small perturbations of a black hole correspond to small deviations from thermodynamic equilibrium in a dual field theory. For gauge theories with an Einstein gravity dual, the AdS/CFT correspondence predicts a universal value for the ratio of the shear viscosity to the entropy density, η/s = 1/4π. It was conjectured recently that all fluids conform to the lower bound: η/s ≥ 1/4π. This conjectured bound has been the focus of much recent attention. However, despite the flurry of research in this field we still lack a proof for the general validity of the bound. In this essay we show that this mysterious bound is actually a direct outcome of the interplay between gravity, quantum theory, and thermodynamics.

scholarly journals SOUND WAVES IN STRONGLY COUPLED NON-CONFORMAL GAUGE THEORY PLASMA

2005 ◽  
Vol 20 (27) ◽  
pp. 6298-6306 ◽  
Author(s):  
PAOLO BENINCASA
Keyword(s):  
Gauge Theory ◽  
Bulk Viscosity ◽  
Speed Of Sound ◽  
Gauge Theories ◽  
Temperature Limit ◽  
Sound Waves ◽  
Strongly Coupled ◽  
Conformal Theory ◽  
High Temperature Limit ◽  
Conformal Gauge

Gauge/string correspondence provides an efficient method to investigate gauge theories. In this talk we discuss the results of the paper (to appear) by P. Benincasa, A. Buchel and A. O. Starinets, where the propagation of sound waves is studied in a strongly coupled non-conformal gauge theory plasma. In particular, a prediction for the speed of sound as well as for the bulk viscosity is made for the [Formula: see text] gauge theory in the high temperature limit. As expected, the results achieved show a deviation from the speed of sound and the bulk viscosity for a conformal theory. It is pointed out that such results depend on the particular gauge theory considered.

scholarly journals The World as Quarks, Leptons and Bosons

1976 ◽  
Vol 29 (6) ◽  
pp. 347 ◽  
Author(s):  
M Gell-Mann
Keyword(s):  
Gauge Theory ◽  
Gauge Theories ◽  
Strong Interactions ◽  
Gauge Bosons ◽  
Yang Mills ◽  
Electromagnetic Interactions ◽  
The World

A descriptive review is given of gauge theories of weak, electromagnetic and strong interactions. The strong interactions are interpreted in terms of an unbroken Yang-Mills gauge theory based on SU(3) colour symmetry of quarks and gluons. The confinement mechanism of quarks, gluons and other nonsinglets is discussed. The unification of the weak and electromagnetic interactions through a broken Yang-Mills gauge theory is described. In total the basic constituents are then the quarks, leptons and gauge bosons.

scholarly journals CONFINEMENT IN GAUGE THEORIES FROM THE CONDENSATION OF WORLD SHEET DEFECTS IN LIOUVILLE STRING

1999 ◽  
Vol 14 (24) ◽  
pp. 3761-3788 ◽  
Author(s):  
JOHN ELLIS ◽  
N. E. MAVROMATOS
Keyword(s):  
Black Holes ◽  
Gauge Theory ◽  
Wilson Loop ◽  
Degrees Of Freedom ◽  
Gauge Theories ◽  
String Tension ◽  
Magnetic Monopoles ◽  
Target Space ◽  
De Sitter ◽  
World Sheet

We present a Liouville-string approach to confinement in four-dimensional gauge theories, which extends previous approaches to include nonconformal theories. We consider Liouville field theory on world sheets whose boundaries are the Wilson loops of gauge theory, which exhibit vortex and spike defects. We show that world sheet vortex condensation occurs when the Wilson loop is embedded in four target–space–time dimensions, and show that this corresponds to the condensation of gauge magnetic monopoles in target–space. We also show that vortex condensation generates an effective string tension corresponding to the confinement of electric degrees of freedom. The tension is independent of the string length in a gauge theory whose electric coupling varies logarithmically with the length scale. The Liouville field is naturally interpreted as an extra target dimension, with an anti-de-Sitter (AdS) structure induced by recoil effects on the gauge monopoles, interpreted as D branes of the effective string theory. Black holes in the bulk AdS space correspond to world sheet defects, so that phases of the bulk gravitational system correspond to the different world sheet phases, and hence to different phases of the four-dimensional gauge theory. Deconfinement is associated with a Berezinskii–Kosterlitz–Thouless transition of vortices on the Wilson-loop world sheet, corresponding in turn to a phase transition of the black holes in the bulk AdS space.

THE NAMBU-JONA-LASINIO MODEL AND GAUGE THEORIES IN 2+1 DIMENSIONS

1991 ◽  
Vol 06 (04) ◽  
pp. 667-694 ◽  
Author(s):  
K.M. COSTA
Keyword(s):  
Gauge Theory ◽  
Invariant Theory ◽  
Gauge Theories ◽  
Leading Order ◽  
Coupling Constant ◽  
Gauge Invariant ◽  
Strongly Coupled ◽  
Njl Model ◽  
Weakly Coupled ◽  
Bare Coupling Constant

The weakly coupled globally invariant Nambu-Jona-Lasino (NJL) model in 2+1 dimensions is shown to be equivalent to a strongly coupled gauge theory. This equivalence is demonstrated for the renormalized theories in the 1/N expansion utilizing an unconventional, cutoff-dependent bare coupling constant to take the limit of weak or strong bare couplings. The weakly coupled Abelian NJL model is renormalized to order 1/N and compared to a renormalized strongly coupled QED3. Next, the U(2) globally invariant NJL model is studied in the broken phase and renormalized to leading order. The resulting U(1)×U(1) gauge-invariant theory is shown to be equivalent to a spontaneously broken U(2) gauge theory analyzed in the 1/N expansion.

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