Related papers: Noncommutative Solitons and Intersecting D-Branes
The non-commutative geometry of a large auxiliary $B$-field simplifies the construction of D-branes as solitons in open string field theory. Similarly, fundamental strings are constructed as localized flux tubes in the string field theory.…
In this thesis we discuss some nonperturbative and noncommutative aspects of string theory. We present low-energy background field solutions corresponding to various D-branes (and their bound states) and intersecting branes in flat and…
We find exact solitons in a large class of noncommutative gauge theories using a simple solution generating technique. The solitons in the effective field theory description of open string field theory are interpreted as D-branes for any…
In the noncommutative field theory of open strings in a B-field, D-branes arise as solitons described as projection operators or partial isometries in a $C^*$ algebra. We discuss how D-branes on orbifolds fit naturally into this algebraic…
D-branes are string theory solitons defined by boundary conditions on open strings that end on them. They play an important role in the non-perturbative dynamics of string theory and have found a wide range of applications. These lectures…
We investigate and interpret a large class of soliton solutions found in noncommutative tachyon condensation. These constructions make extensive use of the idea that Dp-branes may be built out of lower dimensional branes. Finally we comment…
A mathematical introduction to the classical solutions of noncommutative field theory is presented, with emphasis on how they may be understood as states of D-branes in Type II superstring theory. Both scalar field theory and gauge theory…
We consider a Dp brane within a D9 brane in the presence of a B-field whose polarization is {\em transverse} to the Dp brane. To be definite, we take a D3-D9 system. It is observed that the system has the same pattern of supersymmetry…
The purpose of this talk is to review a few issues concerning noncommutativity arising from String Theory. In particular, it is shown how in Type IIB Theory, the annihilation of a D3-\bar{D3} brane pair yields a D1-string. This object, in…
On a noncommutative space of rank-1, we construct a codimension-one soliton explicitly and, in the context of noncommutative bosonic open string field theory, identify it with the D24-brane. We compute the tension of the proposed D24-brane,…
In the first part of this work we consider an unstable non-BPS Dp-\bar{Dp}-brane pair in Type II superstring theory. Turning on a background NS-NS B-field (constant and nonzero along two spatial directions), we show that the tachyon…
We construct BRST invariant solitonic states in the OSp invariant string field theory for closed bosonic strings. Our construction is a generalization of the one given in the noncritical case. These states are made by using the boundary…
We describe the intersecting brane configurations, consisting of NS-branes, D4-branes(and anti-D4-branes), in type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua of N=1 SU(N_c) x SU(N_c') x SU(N_c'') gauge theory…
Solitonic objects play a central role in gauge and string theory (as, e.g., monopoles, black holes, D-branes, etc.). Certain string backgrounds produce a noncommutative deformation of the low-energy effective field theory, which allows for…
We point out some intriguing analogies between field theoretic solitons (topological defects) and D-branes. Annihilating soliton-antisoliton pairs can produce stable solitons of lower dimensionality. Solitons that localize massless gauge…
We construct an exact soliton, which represents a BPS Dp-brane, in a boundary string field theory action of infinitely many non-BPS D(p-1)-branes. Furthermore, we show that this soliton can be regarded as an exact soliton in the full string…
It has been conjectured that condensation of tachyons on a bosonic D-brane gives rise to vacuum / soliton solutions which are independent of the initial magnetic field on the D-brane. We present evidence for this conjecture using results…
Techniques of non-commutative field theories have proven to be useful in describing D-branes as tachyonic solitons in open string theory. However, this procedure also leads to unwanted degeneracy of solutions not present in the spectrum of…
We study pairs of planar D-branes intersecting on null hypersurfaces, and other related configurations. These are supersymmetric and have finite energy density. They provide open-string analogues of the parabolic orbifold and null-fluxbrane…
We review the recent developments in our understanding of non-BPS states and branes in string theory. The topics include 1) construction of unstable non-BPS D-branes in type IIA and type IIB string theories, 2) construction of stable…