Showing papers by "Tadashi Takayanagi published in 2001"
TL;DR: In this paper, the boundary string field theory description of brane-antibrane systems is given, and the tachyon potential and the Tachyon condensation are discussed exactly.
Abstract: In this paper we give the boundary string field theory description of brane-antibrane systems. From the world-sheet action of brane-antibrane systems we obtain the tachyon potential and discuss the tachyon condensation exactly. We also find the world-volume action including the gauge fields. Moreover we determine RR-couplings exactly for non-BPS branes and brane-antibranes. These couplings are written by superconnections and correspond to K1(M) and K0(M) for the non-BPS branes and brane-antibranes, respectively. We also show that Myers terms appear if we include the transverse scalars in the boundary sigma model action.
243 citations
TL;DR: In this paper, it was shown that the non-compact abelian orbifolds are realized as special limits of parameters in type-II (NSNS) background and its higher-dimensional generalizations.
Abstract: In this paper we explicitly show that the various non-compact abelian orbifolds are realized as special limits of parameters in type-II (NSNS) Melvin background and its higher-dimensional generalizations. As a result the supersymmetric ALE spaces (A-type 2/N) and non-supersymmetric orbifolds in type-II and type-0 theory are all connected with each other by the exactly marginal deformation. Our results provide new examples of the duality between type-II and type-0 string theory. We also discuss the decay of unstable backgrounds in this model which include closed string tachyons.
77 citations
TL;DR: In this paper, the D-brane spectra in the Melvin background were determined by constructing their boundary states explicitly, where some of the Dbranes are supersymmetric.
Abstract: In this paper we discuss D-branes in the Melvin background and its supersymmetric generalizations. In particular we determine the D-brane spectra in these backgrounds by constructing their boundary states explicitly, where some of the D-branes are supersymmetric. The results sensitively depend on whether the value of magnetic flux in the Melvin background is rational or irrational. For the rational case the D-branes are regarded as the generalizations of fractional D-branes in abelian orbifolds n/N of type-II or type-0 string theory. For the irrational case we found a very limited spectrum. Since the background includes the non-trivial H-flux, the D-branes will provide interesting examples from the viewpoint of the non-commutative geometry.
64 citations
TL;DR: In this paper, non-commutative solitons on a non-Commutative torus and their application to tachyon condensation were discussed and the resulting soliton spectrum is consistent with T duality and is surprisingly interesting.
Abstract: We discuss noncommutative solitons on a noncommutative torus and their application to tachyon condensation. In the large B limit, they can be exactly described by the Powers-Rieffel projection operators known in the mathematical literature. The resulting soliton spectrum is consistent with T duality and is surprisingly interesting. It is shown that an instability arises for any D-branes, leading to the decay into many smaller D-branes. This phenomenon is the consequence of the fact that the K-homology for a type II von Neumann factor is labeled by R.
51 citations
TL;DR: In this paper, a brane-antibrane system and a non-BPS D-brane in SU(2) WZW model were studied and the vertex operator formalism was used to find the generation of codimension two D2-branes after the condensation.
41 citations
TL;DR: In this article, the exact non-commutative solutions on tori were constructed by applying the gauge Morita equivalence between the constant curvature projective modules, and the results showed that these solutions can be generated by applying a general framework of the Non-Commutative Geometry based on the notion of Morita Equivalence.
Abstract: We construct the exact non-commutative solutions on tori. This gives an exact description of tachyon condensation on bosonic D-branes, non-BPS D-branes and brane-antibrane systems. We obtain various bound states of D-branes after the tachyon condensation. Our results show that these solutions can be generated by applying the gauge Morita equivalence between the constant curvature projective modules. We argue that there is a general framework of the non-commutative geometry based on the notion of Morita equivalence which underlies this specific example.
29 citations
TL;DR: In this article, the exact non-commutative solutions on tori were constructed by applying the gauge Morita equivalence between the constant curvature projective modules, which underlies this specific example.
Abstract: We construct the exact noncommutative solutions on tori. This gives an exact description of tachyon condensation on bosonic D-branes, non-BPS D-branes and brane-antibrane systems. We obtain various bound states of D-branes after the tachyon condensation. Our results show that these solutions can be generated by applying the gauge Morita equivalence between the constant curvature projective modules. We argue that there is a general framework of the noncommutative geometry based on the notion of Morita equivalence which underlies this specific example.
24 citations
TL;DR: In this paper, the authors studied tachyon condensation on brane-antibrane systems in orbifold theories from the viewpoint of boundary string field theory and showed that the condensation of holomorphic Tachyon fields generates various fractional D-branes.
20 citations
TL;DR: In this paper, a mathematical interpretation of tachyon condensation on (three-dimensional) orbifolds within the framework of boundary string field theory (BSFT) is presented, explicitly showing that important parts of decay modes in brane-antibrane systems with N = 2 boundary supersymmetry can be interpreted as the McKay correspondence described as complexes.
11 citations
TL;DR: In this article, a mathematical interpretation of tachyon condensation on (three dimensional) orbifolds within the framework of boundary string field theory (BSFT) is presented, explicitly showing that important parts of decay modes in brane-antibrane systems with N=2 boundary supersymmetry can be interpreted as the McKay correspondence described as complexes.
Abstract: In this short note we present a mathematical interpretation of tachyon condensation on (three dimensional) orbifolds within the framework of boundary string field theory (BSFT). We explicitly show that important parts of decay modes in brane-antibrane systems with N=2 boundary supersymmetry can be interpreted as the McKay correspondence described as complexes. This will give an example of the recent interpretation of D-branes as derived category. We also discuss the N=4 boundary supersymmetry as a more refined structure.
11 citations
TL;DR: In this paper, the D-brane spectra in the Melvin background were determined by constructing their boundary states explicitly, where some of the Dbranes are supersymmetric.
Abstract: In this paper we discuss D-branes in the Melvin background and its supersymmetric generalizations. In particular we determine the D-brane spectra in these backgrounds by constructing their boundary states explicitly, where some of the D-branes are supersymmetric. The results sensitively depend on whether the value of magnetic flux in the Melvin background is rational or irrational. For the rational case the D-branes are regarded as the generalizations of fractional D-branes in abelian orbifolds ${\bf C^n/Z_N}$ of type II or type 0 string theory. For the irrational case we found a very limited spectrum. Since the background includes the nontrivial H-flux, the D-branes will provide interesting examples from the viewpoint of the noncommutative geometry.
TL;DR: In this article, the authors explicitly show that the various noncompact abelian orbifolds are realized as special limits of parameters in type II (NSNS) background and its higher dimensional generalizations.
Abstract: In this paper we explicitly show that the various noncompact abelian orbifolds are realized as special limits of parameters in type II (NSNS) Melvin background and its higher dimensional generalizations. As a result the supersymmetric ALE spaces (A-type C^2/Z_N) and nonsupersymmetric orbifolds in type II and type 0 theory are all connected with each other by the exactly marginal deformation. Our results provide new examples of the duality between type II and type 0 string theory. We also discuss the decay of unstable backgrounds in this model which include closed string tachyons.
TL;DR: In this article, the D-brane spectrum in the Melvin background with nonconstant NSNS B-field was examined from the viewpoint of its world-volume and string world-sheet theory, and the stable D2-D0 bound state was shown even though it does not wrap any nontrivial cycles.
Abstract: In this paper we reexamine the D-brane spectrum in the Melvin background with nonconstant NSNS B-field from the viewpoint of its world-volume and string world-sheet theory. We find that the stable D2-D0 bound state exists even though it does not wrap any nontrivial cycles. We show that this system is stabilized by the presence of the NSNS B-field and the magnetic flux F. Moreover from the non-abelian world-volume theory of D0-branes the bound state is regarded as a system of D0-branes expanding into a fuzzy torus.
TL;DR: In this article, the authors studied tachyon condensation on brane-antibrane systems in orbifold theories from the viewpoint of boundary string field theory and showed that the condensation of holomorphic Tachyon fields generates various fractional D-branes.
Abstract: We study tachyon condensation on brane-antibrane systems in orbifold theories from the viewpoint of boundary string field theory. We show that the condensation of holomorphic tachyon fields generates various fractional D-branes. The boundary N=2 supersymmetry in the world-sheet theory ensures this result exactly. Furthermore, our results are consistent with the twisted RR-charges from detailed calculations of boundary states. We also discuss the generation of RR-charges due to holomorphic tachyon fields on multiple brane-antibrane pairs in flat space.