Related papers: Strings from Nambu-Goto to Polyakov and back
We discuss a string-theory-derived mechanism for localized gravity, which produces a deviation from Newton's law of gravitation at cosmological distances. This mechanism can be realized for general non-compact Calabi-Yau manifolds,…
We further develop the string $1/c^2$ expansion of closed bosonic string theory, where $c$ is the speed of light. The expansion will be performed up to and including the next-to-next-to-leading order (NNLO). We show that the next-to-leading…
A derivation of N=1 supergravity action from string theory is presented. Starting from a Nambu-Goto bosonic string, matter field is introduced to obtain a superstring in four dimension. The excitation quanta of this string contain graviton…
We study duals to field theories in two dimensions with N=(4,4) SUSY. The string backgrounds reproduce certain non-perturbative aspects of the dual field theory with a large number of colors N_c and a tunable number of flavors N_f.…
Recently it was shown that NCOS theories are part of a ten-dimensional theory known as Non-relativistic Wound string theory. We clarify the sense in which gravity is present in this theory. We show that Wound string theory contains…
In these lectures we give a brief introduction to perturbative and non-perturbative string theory. The outline is the following: 1. Introduction to perturbative string theory 1.1 From point particle to extended objects 1.2 Free closed and…
Electromagnetic plane waves provide examples of time-dependent open string backgrounds free of $\alpha'$ corrections. The solvable case of open strings in a quadrupolar wave front, analogous to pp-waves for closed strings, is discussed. In…
We obtain a non-relativistic diffeomorphism invariant string action as a special limit of the Nambu-Goto action in an FLRW background. We use this action to study non-relativistic string dynamics in an expanding universe and construct an…
Recently, a new framework for solving the hierarchy problem has been proposed which does not rely on low energy supersymmetry or technicolor. The gravitational and gauge interactions unite at the electroweak scale, and the observed weakness…
Montonen and Olive's conjecture in 1977 that some theories possess a duality symmetry that interchanges the electrically charged particle with that of negatively charged t' Hooft-Polyakov monopoles which relates strong coupling to weak…
We argue for the existence of phase transitions in $3+1$ dimensions associated with the appearance of tensionless strings. The massless spectrum of this theory does not contain a graviton: it consists of one $N=2$ vector multiplet and one…
We study large dimensions and low string scale in four-dimensional compactifications of type II theories of closed strings at weak coupling. We find that the fundamental string scale, together with all compact dimensions, can be at the TeV,…
The use of the AdS/CFT correspondence to arrive at quiver gauge field theories is discussed. An abelian orbifold with the finite group $Z_{p}$ can give rise to a nonsupersymmetric $G = U(N)^p$ gauge theory with chiral fermions and complex…
The study of curved D-brane geometries in type II strings implies a general relation between local singularities $\cx W$ of Calabi-Yau manifolds and gravity free supersymmetric QFT's. The minimal supersymmetric case is described by F-theory…
This paper describes my talk given to the 27th Johns Hopkins Workshop: Symmetries and Mysteries of M Theory, G\"oteborg, Sweden, 24-26 August, 2003. After a brief introduction to the lightcone worldsheet formalism for summing the planar…
In this short note we give an overview of recent work on string propagation on stacks and applications to gauged linear sigma models. We begin by outlining noneffective orbifolds (orbifolds in which a subgroup acts trivially) and related…
We study the dynamics and evolution of Nambu-Goto strings in a warped spacetime, where the warp factor is a function of the internal coordinates giving rise to a `throat' region. The microscopic equations of motion for strings in this…
This review is devoted to strings and branes. Firstly, perturbative string theory is introduced. The appearance of various types of branes is discussed. These include orbifold fixed planes, D-branes and orientifold planes. The connection to…
I motivate and discuss non-minimal and non-universal models of supersymmetry and supergravity consistent with string unification at $10^{16}$ GeV.
It is observed that three-dimensional G\"odel black holes can be promoted to exact string theory backgrounds through an orbifold of an hyperbolic asymmetric marginal deformation of the SL(2,R) WZW model. Tachyons are found in the spectrum…