Related papers: A microscopic description of absorption in high-en…
We study scattering amplitudes of higher spin closed-string states off D-branes. For states in the `first Regge trajectory' we find remarkable simplifications both at tree level and at one loop. We discuss the high energy behavior in the…
We probe the effective worldvolume theory of a set of coinciding D-branes by switching on constant electro-magnetic fields on them. The comparison of the mass spectrum predicted by string theory with the mass spectrum obtained from the…
We study the microcanonical description of string gases in the presence of D-branes. We obtain exact expressions for the single string density of states and draw the regions in phase space where asymptotic approximations are valid. We are…
We show that the boundary state description of a Dp-brane is strictly related to the corresponding classical solution of the low-energy string effective action. By projecting the boundary state on the massless states of the closed string we…
Using standard techniques in string/D-brane scattering amplitude computations, we evaluate the scattering of open strings off D-particles in brane world scenarios. The D-particles are viewed as D3 branes wrapped up around three cycles, and…
The effect of fluxes on open string moduli is studied by analyzing the constraints imposed by supersymmetry on D-branes in type IIB flux backgrounds. We show that generically the conditions of supersymmetry cannot be maintained when moving…
"Brane Supersymmetry Breaking" is a peculiar string-scale mechanism that can unpair Bose and Fermi excitations in orientifold models. It results from the simultaneous presence, in the vacuum, of collections of D-branes and orientifolds that…
In this paper, we evaluate the lifetime of the light stringy states that emerge in intersecting D-brane realisations of the Standard Model. For concreteness, we focus on a light massive scalar decaying into two massless fermions. Given the…
The strongly intensive observable between multiplicities in two acceptance windows separated in rapidity and azimuth is calculated in the model with quark-gluon strings acting as sources. The dependence of this observable on the…
We find examples in string theory of locally wrapped D-branes. These excitations mimic skyrmions in that they correspond to topological excitations of the scalar fields parametrizing the brane motion in the space transverse to its…
We study the behavior of D-branes at distances far shorter than the string length scale~$l_s$. We argue that short-distance phenomena are described by the IR behavior of the D-brane world-volume quantum theory. This description is valid…
Picking up, laying down, colliding, rolling, and peeling are partial-contact interactions involving moving discontinuities. We examine the balances of momentum and energy across a moving discontinuity in a string, with allowance for…
$D$-brane boundary states for type II superstrings are constructed by enforcing the conditions that preserve half of the space-time supersymmetry. A light-cone coordinate frame is used where time is identified as one of the coordinates…
We discuss a new class of string and p-brane models where the string/brane tension appears as an additional dynamical degree of freedom instead of being introduced by hand as an ad hoc dimensionfull scale. The latter property turns out to…
When high energy strings scatter at fixed angle, their amplitudes characteristically fall off exponentially with energy, ${\cal A} \sim \exp(-s \times const.)$. We show that in a compact space this suppression disappears for certain…
In this review branes of string theory are described from three different perspectives: as endpoints of open string, as supergravity backgrounds with BPS properties, as dynamical objects with gauge invariant actions. Based on these…
Matrix elements of electron-light interactions for armchair and zigzag graphene nanoribbons are constructed analytically using a tight-binding model. The changes in wavenumber ($\Delta n$) and pseudospin are the necessary elements if we are…
We investigate the general solution with the symmetry ISO(1,p)xSO(9-p) of Type II supergravity (the three-parameter solution) from the viewpoint of the superstring theory. We find that one of the three parameters (c_1) is closely related to…
All the models of elementary particles and their interactions derived from String Theory involve a compact six-dimensional internal space. Its volume and shape should be fixed or stabilized, since otherwise massless scalar fields (moduli)…
We discuss the dynamical D$p$-brane solutions describing any number of D$p$-branes whose relative orientations are given by certain SU(2) rotations. These are the generalization of the static angled D$p$-brane solutions. We study the…