Related papers: The open string pair production, its enhancement a…
We study the boundary state associated with the decay of an unstable D-brane with uniform electric field, 1>e>0 in the string units. Compactifying the D-brane along the direction of the electric field, we find that the decay process is…
We study decay of unstable D-branes in string theory in the presence of electric field, and show that the classical open string theory results for various properties of the final state agree with the properties of closed string states into…
The rate of pair production of open strings in general uniform electromagnetic fields is calculated in various space-time dimensions. The corrections with respect to the case of pure electric backgrounds are displayed. In particular, a…
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…
In this article we study D1-D3 (or $\bar{\textrm{D}3}$) brane systems with generic constant electric and magnetic fluxes in IIB string theory. We work out all possible supersymmetric configurations and find out via T-duality all of them and…
This thesis investigates correspondences between open and closed strings. This is done on the level of coupled open-closed moduli spaces and from a string field theoretic point of view. The construction of boundary string field theory on…
The use of a non-Riemannian measure of integration in the action of strings and branes allows the possibility of dynamical tension. In particular, lower dimensional objects living in the string/brane can induce discontinuities in the…
We investigate open string theory on backreacting D3-branes using a spacetime approach. We study in detail the half-BPS supergravity solutions describing open strings ending on D3-branes, in the near horizon of the D3-branes. We recover…
Consider a system consisting of D$p$ and D$p'$, placed parallel at a separation and with $p - p' = 2 n$ (assuming $p \ge p'$, the integer $n \ge 0$ and $p' > 0$). When either D$p$ or D$p'$ carries a worldvolume electric flux, one in general…
In this paper we study QED on the noncommutative space in the constant electro-magnetic field background. Using the explicit solutions of the noncommutative version of Dirac equation in such background, we show that there are well-defined…
We investigate the criterion, on the Born-Infeld background fields, for the open string pair creation to occur in D$p$-(anti-)D$p$-brane systems. Although the pair creation occurs generically in both D$p$-D$p$ and D$p$-anti-D$p$ systems for…
Over the last few years, string theory has changed profoundly. Most importantly, novel duality relations have emerged which involve gauge theories of brane excitations on one side and various closed string backgrounds on the other. In this…
We compute the annulus diagram corresponding to the interaction of a fractional D3 brane with a gauge field on its world-volume and a stack of N fractional D3 branes on the orbifolds C^2 /Z_2 and C^3/Z_2 x Z_2. We show that its logarithmic…
Dvali and Shifman have proposed a field-theoretic mechanism for localizing gauge fields to "branes" in higher dimensional spaces using confinement in a bulk gauge theory. The resulting objects have a number of qualitative features in common…
We examine the system where a string stretches between pair of D-branes, and study the bending of the D-brane caused by the tension of the string. If the distance between the pair of D-branes is sent to infinity, the tension of the string…
We study the pair creation of point-particles and strings in a time-dependent, weak gravitational field. We find that, for massive string states, there are surprising and significant differences between the string and point-particle…
A quantum-mechanical technique is used within the framework of U(2) super-Yang-Mills theory to investigate what happens in the process after recombination of two D-p-branes at one angle. Two types of initial conditions are considered, one…
We study effective quiver gauge theories arising from a stack of D3-branes on certain Calabi-Yau singularities. Our point of view is a first principle approach via open topological string theory. This means that we construct the natural…
We discuss the processes of brane bubble nucleation induced by the external branes. The quasiclassical solution for the nucleation by the single external brane has been found in the case when the brane junctions are possible. Exponential…
There is a subtle difference between the open string dynamics determined by the original dual resonance models and that determined by D-brane constructions within critical closed string theory. For instance, in contrast to the former, the…