Related papers: Open Strings in Constant Electric and Magnetic Fie…
We investigate analytic classical solutions in open string field theory which are constructed in terms of marginal operators. In the classical background, we evaluate a coupling between an on-shell closed string state and the open string…
A self-consistent string field theory with interaction is formulated. The symmetry algebra of this theory includes, in the low-energy limit, local space-time symmetries, and the Brans-Dicke equation describes a class of low-energy…
In this Thesis we address the issue of consistent higher-spin interactions taking String Theory as a "theoretical laboratory". We thus arrive at a simple expression encompassing all three-point amplitudes for states belonging to the first…
String Theory includes a plethora of higher-spin excitations, which clearly lie behind its most spectacular properties, but whose detailed behavior is largely unknown. Conversely, string interactions contain much useful information on…
A large class of four-dimensional supersymmetric ground states of closed superstrings with a non-zero mass gap are constructed. For such ground states we turn on chromo-magnetic fields as well as curvature. The exact spectrum as function of…
It is shown that strongly correlated electrons on frustrated lattices like pyrochlore, checkerboard or kagome lattice can lead to the appearance of closed and open strings. They are resulting from nonlocal subsidiary conditions which…
We analyze open membranes immersed in a magnetic three-form field-strength $C$. While cylindrical membranes in the absence of $C$ behave like tensionless strings, when the $C$ flux is present the strings polarize into thin membrane ribbons,…
The bi-local fields are the quantum fields of two-particle systems, the bi-local, systems, bounded by relativistic potentials. Since those form constrained dynamical systems, it is limited to introduce the interactions of the bi-local…
We consider massless string scattering amplitudes in a limit where the number of external particles becomes very large, while the energy of each particle remains small. Using the growth of the volume of the relevant moduli space, and by…
This paper considers interactions between closed strings and open strings satisfying either Neumann or constant (point-like) Dirichlet boundary conditions in a BRST formalism in the critical dimension. With Neumann conditions this…
In these lecture notes we give an introduction to the kinetic equation approach to pair production form the vacuum in strong, time-dependent external fields (dynamical Schwinger process). We first give a derivation of the kinetic equation…
This presentation is intended to give a flavour of the physics to be studied and discovered by exploiting the interface between string theory, M-theory and field theory provided by the dynamics of extended objects called `branes', and their…
The vacuum of quantum electrodynamics is unstable against the formation of many-body states in the presence of an external electric field, manifesting itself as the creation of electron-positron pairs (Schwinger effect). This effect has…
We show that the Z-strings of the standard electroweak theory can be stabilized by strong external magnetic fields, provided that $\beta^{1/2} \equiv M_H/M_Z\leq 1$, where $M_H$ and $M_Z$ are the Higgs and Z masses. The magnetic fields…
Lattice-based string formation algorithms can, at least in principle, be reduced to the study of the statistics of the corresponding aperiodic random walk. Since in three or more dimensions such walks are transient this approach necessarily…
String theory predicts that the couplings of Nature descend from dynamical fields. All known string-motivated particle physics models also come with a wide range of possible extra sectors. It is common to posit that such moduli are frozen…
String theories inspire a new formalism for their low-energy limits. In this approach to these field theories, spacetime duality and stringy left/right handedness are manifest. Enlarged tangent-space symmetries allow the different fields…
We study particles creation in arbitrary space-time dimensions by external electric fields, in particular, by fields, which are acting for a finite time. The time and dimensional analysis of the vacuum instability is presented. It is shown…
The Schr\"odinger equation is solved for the wave function of an electron moving in a superposition of external constant and uniform electric and magnetic fields at an arbitrary angle between the field directions. The changing of the…
We address the problem of describing different closed string backgrounds in background independent open string field theory: A shift in the closed string background corresponds to a collective excitation of open strings. As an illustration…