Related papers: Spiky Strings on NS5-branes
Five-dimensional non-extreme rotating black holes with large NS-NS five-brane and fundamental string charge are shown to be described by a conformal sigma model, which is a marginal integrable deformation of six-dimensional SL(2,R) x SU(2)…
We treat RR flux backgrounds of type II string theory in the framework of closed superstring field theory based on the NSR formalism, focusing on two examples: (1) the pp-wave background supported by 5-form flux, and (2) $AdS_3\times…
In this PhD thesis the low energy effective actions for D-branes and the M5-brane are used to analyze the dynamics of brane probes moving in the geometry created by diverse supergravity backgrounds. It begins with an introduction to string…
An effective action for NS5-branes coupled to supergravity is used to derive the full 10d form of horizon-free BPS solutions of fivebranes carrying momentum waves, including both transverse scalar and internal gauge excitations of the…
A system of k Neveu-Schwarz (NS) 5-branes of type II string theory with one transverse direction compactified on a circle admits various unstable D-brane systems, - some with geometric instability arising out of being placed at a point of…
We consider self-avoiding Nambu-Goto open strings on a random surface. We have shown that the partition function of such a string theory can be calculated exactly. The string susceptibility for the disk is evaluated to be $-\frac{1}{2}$. We…
The Matrix theory description of Type IIA string theory on a compact K3 surface as the theory of Neveu-Schwarz five-branes on $\tilde{K3}\times S^1$ is analyzed. The full multiplet of space-time BPS states is identified in the five-brane…
The effective action on long strings, such as confining strings in pure Yang-Mills theories, is well-approximated by the Nambu-Goto action, but this action cannot be exact. The leading possible corrections to this action (in a long string…
We study the stability of the giant gravitons in the string theory background with NSNS B field. We consider the perturbation of giant gravitons formed by a probe D$(8-p)$ brane in the background generated by D$(p-2)$-D$(p)$ branes for $2…
We construct two new SL(2,Z) invariant vacua of type IIB string theory which are bound states of $(p,q)$ strings with $(m,n)$ 5-branes, written as ((F, D1), (NS5, D5)) and preserve 1/4 of the full space-time supersymmetries. For the first…
We construct an approximate static gravitational solution of the Einstein equations, with negative cosmological constant, describing a test black string stretching from the boundary of the Schwarzschild-AdS_5 black brane toward the horizon.…
We study the dynamics of Nambu--Goto strings with junctions at which three strings meet. In particular, we exhibit one simple exact solution and examine the process of intercommuting of two straight strings, in which they exchange partners…
We study solutions for the rotating strings on the sphere with a background NS-NS field and on the Anti-de-Sitter spacetime. We show the existence of magnon and single spike solutions on R$\times$S$^2$ in the presence of constant magnetic…
The near-horizon region of Neveu-Schwarz fivebranes provides interesting examples of gauge/gravity duality. We revisit the structure of wrapped and/or intersecting fivebranes using the tools of null-gauged WZW models in worldsheet string…
In this note we investigate certain topological aspects of the effective action of the NS5-brane in type IIA string theory. To facilitate the study of the corresponding partition function, we define a cohomology class whose vanishing is a…
We initiate the study of M-strings in the thermodynamic limit. In this limit the BPS partition function of M5 branes localizes on configurations with a large number of strings which leads to a reformulation of the partition function in…
We construct supergravity solutions describing branes (D2-branes or NS5-branes or waves) localized within D6-branes in the region close to the core of the D6-branes. Other similar string-theory and M-theory `near-core' localized solutions…
We study the low-energy effective action governing the transverse fluctuations of a long string, such as a confining flux tube in QCD. We work in the static gauge where this action contains only the transverse excitations of the string. The…
We study a family of classical string solutions with large spins on R x S^3 subspace of AdS_5 x S^5 background, which are related to Complex sine-Gordon solitons via Pohlmeyer's reduction. The equations of motion for the classical strings…
We present a time-dependent solution of the Nambu-Goto action which represents two colliding waves moving at the speed of light. This solution can be decomposed into two distinct regions with different geometries corresponding to shrinking…