Related papers: Closed String Radiation from the Interaction of th…
We develop a novel approach to non-relativistic closed bosonic string theory that is based on a string $1/c^2$ expansion of the relativistic string, where $c$ is the speed of light. This approach has the benefit that one does not need to…
We investigate some aspects of the spectrum of D-branes and their interactions with closed strings. As argued earlier, a collection of many D-strings behaves, at large dilaton values, as a single multiply wound string. We use this result…
Studying dynamics of open strings attached to a D2-brane in a NS two form field background, we find that these open strings act as dipoles of U(1) gauge field of the brane. This provides an string theoretic description of the flux…
String amplitudes with an arbitrary number of world-sheet boundaries on which the coordinates satisfy Dirichlet boundary conditions are analyzed in a path integral framework. Special attention is payed to the novel divergences associated…
We reformulate bosonic boundary string field theory in terms of boundary state. In our formulation, we can formally perform the integration of target space equations of motion for arbitrary field configurations without assuming decoupling…
We determine the consistent D-brane configurations in type II nonsupersymmetric Melvin Background. The D-branes are analysed from three complementary points of view: the effective Born-Infeld action, the open string partition function and…
In this paper, we consider the D-brane, especially ${\rm D}_-$-brane, in the pp-wave background, which has the eight dynamical and the eight kinematical supercharges. Since the pp-wave background has not a SO(8) but a ${\rm SO}(4) \times…
We consider the open string vacuum amplitude determining the interaction between a stack of N D3-branes and a single probe brane. When using light cone gauge, it is clear that the sum of planar diagrams (relevant in the large-N limit) is…
We study the entanglement of closed strings degrees of freedom in order to investigate the microscopic structure and statistics of objects as D-branes. By considering the macroscopic pure state (MPS) limit, whenever the entanglement entropy…
The description of string-theoretic s-branes at g_s=0 as exact worldsheet CFTs with a (lambda cosh X^0) or (lambda e^(X^0)) boundary interaction is considered. Due to the imaginary-time periodicity of the interaction under X^0 -> X^0 + 2 pi…
We study the interaction of two D-particles in the space-time of the shock wave. We first write the amplitude in string theory and find that, at large distances from the shock-wave source, the O(v^4) term in the relative velocity v is an…
In this thesis we study string theory with D-branes and possibly orientifolds in curved or time-dependent spaces. Our study aims at understanding some aspects of curved and time-dependent spaces, notably because of their importance in…
We calculate classically the radiation of the antisymmetric form field generated in the collision of two non-excited membranes moving with ultrarelativistic velocities in five space-time dimensions. The interaction between branes through…
I study a relativistic open string coupling through its endpoints to a plane wave with arbitrary temporal profile. The string's transverse oscillations respond linearly to the external field. This makes it possible to solve the classical…
It has been conjectured that the tachyonic lump solution of the open bosonic string field theory describing a D-brane represents a D-brane of one lower dimension. We place the lump on a circle of finite radius and develop a variant of the…
We study a bosonic open string coupled to a tachyonic background field $T[X]$ and find that the tachyon field can effectively be replaced by a configuration of D-branes placed at either the zeros or the critical points of $T[X]$, depending…
We compute the D-brane tensions in the type IIA plane-wave background by comparing the interaction potential between widely separated D-branes in string theory with the supergravity mode exchange between the D-branes. We found that the…
Boundary interactions of closed-string with open-strings are examined intended to provide a constructive formulation of boundary string field theory. As an illustration, we consider the BPS $D$-brane of the type II superstring in a constant…
The Dirac-Born-Infeld action with transverse scalar fields is considered to study the dynamics of various BPS states. We first describe the characteristic properties of the so-called 1/2 and 1/4 BPS states on the D3 brane, which can be…
Rotation angle of the plane of polarization of the distant galactic radio waves has been estimated in a string inspired axion-dilaton background. It is found that the axion,dual to the field strength of the second rank antisymmetric…