Results 11 - 20
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151
D-branes in Gepner models
, 1997
"... We discuss D-branes from a conformal field theory point of view. In this approach, branes are described by boundary states providing sources for closed string modes, independently of classical notions. The boundary states must satisfy constraints which fall into two classes: The first consists of gl ..."
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Cited by 58 (4 self)
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We discuss D-branes from a conformal field theory point of view. In this approach, branes are described by boundary states providing sources for closed string modes, independently of classical notions. The boundary states must satisfy constraints which fall into two classes: The first consists of gluing conditions between leftand right-moving Virasoro or further symmetry generators, whereas the second encompasses non-linear consistency conditions from world sheet duality, which severely restrict the allowed boundary states. We exploit these conditions to give explicit formulas for boundary states in Gepner models, thereby computing excitation spectra of brane configurations. From the boundary states, brane tensions and RR charges can also be read off directly.
∗-Trek II: ∗n operations, open Wilson lines and the Seiberg-Witten map
, 2000
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Non-commutative World-volume Geometries: Branes on SU(2) and Fuzzy Spheres
, 1999
"... The geometry of D-branes can be probed by open string scattering. If the background carries a non-vanishing B-field, the world-volume becomes noncommutative. Here we explore the quantization of world-volume geometries in a curved background with non-zero Neveu-Schwarz 3-form field strength H = dB. ..."
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Cited by 48 (8 self)
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The geometry of D-branes can be probed by open string scattering. If the background carries a non-vanishing B-field, the world-volume becomes noncommutative. Here we explore the quantization of world-volume geometries in a curved background with non-zero Neveu-Schwarz 3-form field strength H = dB. Using exact and generally applicable methods from boundary conformal field theory, we study the example of open strings in the SU(2) Wess-Zumino-Witten model, and establish a relation with fuzzy spheres or certain (non-associative) deformations thereof. These findings could be of direct relevance for D-branes in the presence of Neveu-Schwarz 5-branes; more importantly, they provide insight into a completely new class of world-volume geometries.
On theories with light-like noncommutativity
- JHEP
"... We show that field theories with light-like noncommutativity, that is with θ0i = −θ1i, are unitary quantum theories, and that they can be obtained as decoupled field theory limits of string theory with D-branes in a background NS-NS B field. For general noncommutativity parameters, we show that nonc ..."
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Cited by 45 (0 self)
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We show that field theories with light-like noncommutativity, that is with θ0i = −θ1i, are unitary quantum theories, and that they can be obtained as decoupled field theory limits of string theory with D-branes in a background NS-NS B field. For general noncommutativity parameters, we show that noncommutative field theories which are unitary can be obtained as decoupled field theory limits of string theory, while those that are not unitary cannot be obtained from string theory because massive open strings do not decouple. We study the different theories with light-like noncommutativity which arise from Type II D-branes. The decoupling limit of the D4-brane seems to lead to a noncommutative field theory deformation of the (2, 0) SCFT of M5-branes, while the D5-brane case leads to a noncommutative variation of “little string theories”. We discuss the DLCQ description of these theories. June
2001c, How noncommutative gauge theories couple to gravity, Nucl
- Phys. B599
"... We study coupling of noncommutative gauge theories on branes to closed string in the bulk. We derive an expression for the gauge theory operator dual to the bulk graviton, both in bosonic string theory and superstring theory. In either case, we find that the coupling is different from what was expec ..."
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Cited by 42 (5 self)
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We study coupling of noncommutative gauge theories on branes to closed string in the bulk. We derive an expression for the gauge theory operator dual to the bulk graviton, both in bosonic string theory and superstring theory. In either case, we find that the coupling is different from what was expected in the literature when the graviton is polarized in the noncommutative directions. In the case of superstring, the expression for the energy-momentum tensor is consistent with the way the bulk metric appears in the action for the noncommutative gauge theory. We also clarify some aspects of the correspondence between operators in the gauge theory and boundary conditions in the Noncommutative gauge theories can be realized as the zero slope limit of open string theory on branes in a background of strong NS-NS two-form field Bij [1- 11]. It was pointed out in [12, 13] that, for each local observable in a gauge theory in commutative space, one can define an observable in the noncommutative version of the theory. The
Stretched strings in noncommutative field theory,” Phys. Rev. D 62 (2000) 066003 [arXiv:hep-th/0004013
- H. Liu 62 J. Michelson, “*-Trek: The one-loop N = 4 noncommutative SYM action,” Nucl. Phys. B
"... Preprint typeset in JHEP style.- HYPER VERSION hep-th/0004013 ..."
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Cited by 24 (4 self)
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Preprint typeset in JHEP style.- HYPER VERSION hep-th/0004013
Gauge bundles and Born-Infeld on the noncommutative torus,” Nucl. Phys. B547
, 1999
"... In this paper, we describe non-abelian gauge bundles with magnetic and electric fluxes on higher dimensional noncommutative tori. We give an explicit construction of a large class of bundles with nonzero magnetic ’t Hooft fluxes. We discuss Morita equivalence between these bundles. The action of the ..."
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Cited by 23 (0 self)
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In this paper, we describe non-abelian gauge bundles with magnetic and electric fluxes on higher dimensional noncommutative tori. We give an explicit construction of a large class of bundles with nonzero magnetic ’t Hooft fluxes. We discuss Morita equivalence between these bundles. The action of the duality is worked out in detail for the four-torus. As an application, we discuss Born-Infeld on this torus, as a description of compactified string theory. We show that the resulting theory, including the fluctuations, is manifestly invariant under the T-duality group SO(4, 4; Z). The U-duality invariant BPS mass-formula is discussed shortly. We comment on a discrepancy of this result with that of a recent calculation. 1
Matrix theory on noncommutative torus
, 1998
"... We consider the compactification of Matrix theory on tori with background antisymmetric tensor field. Douglas and Hull have recently discussed how noncommutative geometry appears on the tori. In this paper, we demonstrate the concrete construction of this compactification of Matrix theory in a simil ..."
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Cited by 22 (0 self)
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We consider the compactification of Matrix theory on tori with background antisymmetric tensor field. Douglas and Hull have recently discussed how noncommutative geometry appears on the tori. In this paper, we demonstrate the concrete construction of this compactification of Matrix theory in a similar way to that previously given by Taylor. March
