Results 1  10
of
151
String theory and noncommutative geometry
 JHEP
, 1999
"... We extend earlier ideas about the appearance of noncommutative geometry in string theory with a nonzero Bfield. We identify a limit in which the entire string dynamics is described by a minimally coupled (supersymmetric) gauge theory on a noncommutative space, and discuss the corrections away from ..."
Abstract

Cited by 794 (8 self)
 Add to MetaCart
(Show Context)
We extend earlier ideas about the appearance of noncommutative geometry in string theory with a nonzero Bfield. We identify a limit in which the entire string dynamics is described by a minimally coupled (supersymmetric) gauge theory on a noncommutative space, and discuss the corrections away from this limit. Our analysis leads us to an equivalence between ordinary gauge fields and noncommutative gauge fields, which is realized by a change of variables that can be described explicitly. This change of variables is checked by comparing the ordinary DiracBornInfeld theory with its noncommutative counterpart. We obtain a new perspective on noncommutative gauge theory on a torus, its Tduality, and Morita equivalence. We also discuss the D0/D4 system, the relation to Mtheory in DLCQ, and a possible noncommutative version of the sixdimensional (2, 0) theory. 8/99
On conformal field theories
 in fourdimensions,” Nucl. Phys. B533
, 1998
"... We review the generalization of field theory to spacetime with noncommuting coordinates, starting with the basics and covering most of the active directions of research. Such theories are now known to emerge from limits of M theory and string theory, and to describe quantum Hall states. In the last ..."
Abstract

Cited by 365 (0 self)
 Add to MetaCart
(Show Context)
We review the generalization of field theory to spacetime with noncommuting coordinates, starting with the basics and covering most of the active directions of research. Such theories are now known to emerge from limits of M theory and string theory, and to describe quantum Hall states. In the last few years they have been studied intensively, and many qualitatively new phenomena have been discovered, both on the classical and quantum level. Submitted to Reviews of Modern Physics.
Supersymmetric worldvolume action for nonBPS
 Dbranes,” JHEP
, 1999
"... We construct the worldvolume action for nonBPS Dbranes in type II string theories. This action is invariant under all the unbroken supersymmetries in the bulk, but these symmetries are realised as spontaneously broken symmetries in the worldvolume theory. Coupling of this action to background su ..."
Abstract

Cited by 175 (6 self)
 Add to MetaCart
(Show Context)
We construct the worldvolume action for nonBPS Dbranes in type II string theories. This action is invariant under all the unbroken supersymmetries in the bulk, but these symmetries are realised as spontaneously broken symmetries in the worldvolume theory. Coupling of this action to background supergravity fields is straightforward. We also discuss the fate of the U(1) gauge field on the Dbrane worldvolume after tachyon condensation. 1
Dbranes and deformation quantization
 JHEP
, 1999
"... In this note we explain how worldvolume geometries of Dbranes can be reconstructed within the microscopic framework where Dbranes are described through boundary conformal field theory. We extract the (noncommutative) worldvolume algebras from the operator product expansions of open string verte ..."
Abstract

Cited by 140 (17 self)
 Add to MetaCart
(Show Context)
In this note we explain how worldvolume geometries of Dbranes can be reconstructed within the microscopic framework where Dbranes are described through boundary conformal field theory. We extract the (noncommutative) worldvolume algebras from the operator product expansions of open string vertex operators. For branes in a flat background with constant nonvanishing Bfield, the operator products are computed perturbatively to all orders in the field strength. The resulting series coincides with Kontsevich’s presentation of the Moyal product. After extending these considerations to fermionic fields we conclude with some remarks on the generalization of our approach to curved backgrounds.
Boundary deformation theory and moduli spaces of Dbranes
, 1999
"... Boundary conformal field theory is the suitable framework for a microscopic treatment of Dbranes in arbitrary CFT backgrounds. In this work, we develop boundary deformation theory in order to study the changes of boundary conditions generated by marginal boundary fields. The deformation parameters ..."
Abstract

Cited by 140 (26 self)
 Add to MetaCart
Boundary conformal field theory is the suitable framework for a microscopic treatment of Dbranes in arbitrary CFT backgrounds. In this work, we develop boundary deformation theory in order to study the changes of boundary conditions generated by marginal boundary fields. The deformation parameters may be regarded as continuous moduli of Dbranes. We identify a large class of boundary fields which are shown to be truly marginal, and we derive closed formulas describing the associated deformations to all orders in perturbation theory. This allows us to study the global topology properties of the moduli space rather than local aspects only. As an example, we analyse in detail the moduli space of c = 1 theories, which displays various stringy phenomena.
Observables of noncommutative gauge theories
 Adv. Theor. Math. Phys
"... We present a unified treatment of classical solutions of noncommutative gauge theories. We find all solutions of the noncommutative YangMills equations of motion in 2 dimensions; and show that they are labeled by two integers—the rank of the gauge group and the magnetic charge. The magnetic vortex ..."
Abstract

Cited by 104 (4 self)
 Add to MetaCart
(Show Context)
We present a unified treatment of classical solutions of noncommutative gauge theories. We find all solutions of the noncommutative YangMills equations of motion in 2 dimensions; and show that they are labeled by two integers—the rank of the gauge group and the magnetic charge. The magnetic vortex solutions are unstable in 2+1 dimensions, but correspond to the full, stable BPS solutions of N = 4 U(1) noncommutative gauge theory in 4 dimensions, that describes N infinite D1 strings that pierce a D3 brane at various points, in the presence of a background Bfield in the SeibergWitten α ′ → 0 limit. We discuss the behavior of gauge invariant observables in the background of the solitons. We use these solutions to construct a panoply of BPS and nonBPS solutions of supersymmetric gauge theories that describe various configurations of Dbranes. We analyze the instabilites of the nonBPS solitons. We also present an exact analytic solution of Recently there has been much interest in the properties of noncommutative gauge theories. The interest in these theories was sparked by the discovery that these emerge as
Higherspin gauge interactions for massive matter fields
 in 3D AdS spacetime,” Nucl. Phys. B 545
, 1999
"... A remarkable feature of the models with interactions exhibiting higherspin (HS) gauge symmetries in d> 2 is that their most symmetric vacua require (anti)de Sitter (AdS) geometry rather than the flat one. In striking parallelism to what might be expected of M theory HS gauge theories describe i ..."
Abstract

Cited by 87 (0 self)
 Add to MetaCart
(Show Context)
A remarkable feature of the models with interactions exhibiting higherspin (HS) gauge symmetries in d> 2 is that their most symmetric vacua require (anti)de Sitter (AdS) geometry rather than the flat one. In striking parallelism to what might be expected of M theory HS gauge theories describe infinite towers of fields of all spins and possess naturally spacetime SUSY and ChanPaton type inner symmetries. In this paper, we analyze at the level of the equations of motion the simplest nontrivial HS model which describes HS gauge interactions (on the top of the usual supergravitational and (ChernSimons) YangMills interactions) of massive spin0 and spin1/2 matter fields in d = 2 + 1 AdS spacetime. The parameter of mass of the matter fields is identified with the vev of a certain auxiliary field in the model. The matter fields are shown to be arranged into d3 N = 2 massive hypermultiplets in certain representations of U(n) × U(m) YangMills gauge groups. Discrete symmetries of the full system are studied, and the related N = 1 supersymmetric truncations with O(n) and Sp(n) YangMills symmetries are constructed. The simplicity of the model allows us to elucidate some general properties of the HS models. In particular, a new result, which can have interesting implications to the higherdimensional models, is that our model is shown to admit an “integrating” flow that proves existence of a nonlocal BäcklundNicolai–type mapping to the free system.
Noncommutative worldvolume geometries
 BRANES ON SU(2) AND FUZZY SPHERES, JHEP 09
, 1999
"... The geometry of Dbranes can be probed by open string scattering. If the background carries a nonvanishing Beld, the worldvolume becomes noncommutative. Here we explore the quantization of worldvolume geometries in a curved background with nonzero NeveuSchwarz 3form eld strength H = dB. Usin ..."
Abstract

Cited by 82 (8 self)
 Add to MetaCart
(Show Context)
The geometry of Dbranes can be probed by open string scattering. If the background carries a nonvanishing Beld, the worldvolume becomes noncommutative. Here we explore the quantization of worldvolume geometries in a curved background with nonzero NeveuSchwarz 3form eld strength H = dB. Using exact and generally applicable methods from boundary conformal eld theory, we study the example of open strings in the SU(2) WessZuminoWitten model, and establish a relation with fuzzy spheres or certain (nonassociative) deformations thereof. These ndings could be of direct relevance for Dbranes in the presence of NeveuSchwarz 5branes; more importantly, they provide insight into a completely new class of worldvolume geometries.
General properties of noncommutative field theories
, 2003
"... In this paper we study general properties of noncommutative field theories obtained from the SeibergWitten limit of string theories in the presence of an external Bfield. We analyze the extension of the Wightman axioms to this context and explore their consequences, in particular we present a proo ..."
Abstract

Cited by 72 (3 self)
 Add to MetaCart
In this paper we study general properties of noncommutative field theories obtained from the SeibergWitten limit of string theories in the presence of an external Bfield. We analyze the extension of the Wightman axioms to this context and explore their consequences, in particular we present a proof of the CPT theorem for theories with spacespace noncommutativity. We analyze as well questions associated to the spinstatistics connections, and show that noncommutative N = 4, U(1) gauge theory can be softly broken to N = 0 satisfying the axioms and providing an example where the Wilsonian low energy effective action can be constructed without UV/IR problems, after a judicious choice of soft breaking parameters is made. We also assess the phenomenological prospects of such a theory, which are in fact rather negative.
The Cdeformation of gluino and nonplanar diagrams
 Adv. Theor. Math. Phys
"... We consider a deformation of N = 1 supersymmetric gauge theories in four dimensions, which we call the Cdeformation, where the gluino field satisfies a Cliffordlike algebra dictated by a selfdual twoform, instead of the standard Grassmannian algebra. The superpotential of the deformed gauge theo ..."
Abstract

Cited by 63 (1 self)
 Add to MetaCart
(Show Context)
We consider a deformation of N = 1 supersymmetric gauge theories in four dimensions, which we call the Cdeformation, where the gluino field satisfies a Cliffordlike algebra dictated by a selfdual twoform, instead of the standard Grassmannian algebra. The superpotential of the deformed gauge theory is computed by the full partition function of an associated matrix model (or more generally a bosonic gauge theory), including nonplanar diagrams. In this identification, the strength of the twoform controls the genus expansion of the matrix model partition function. For the case of pure N = 1 YangMills this deformation leads to the identification of the all genus partition function of c = 1 noncritical bosonic string at selfdual radius as the glueball superpotential. Though the Cdeformation violates Lorentz invariance, the deformed Fterms are Lorentz invariant and the Lorentz violation is screened in the IR. 1