Related papers: String-Like Description of Gravity and Possible Ap…
This is a note on the coupled supergravity-tachyon matter system, which has been earlier proposed as a candidate for the effective space-time description of S-branes. In particular, we study an ansatz with the maximal ISO(p+1)xSO(8-p,1)…
1. Preliminaries. 2. Heterotic string and motivations for large volume compactifications; 2.1 Gauge coupling unification; 2.2 Supersymmetry breaking by compactification. 3. M-theory on S^1/Z_2 \times Calabi-Yau. 4. Type I/I' string theory…
Inspired by the Poisson Sigma Model and its relation to 2d gravity, we consider models governing morphisms from TSigma to any Lie algebroid E, where Sigma is regarded as d-dimensional spacetime manifold. We address the question of minimal…
Unique twistor--like Lorentz harmonic formulation for all N=1 supersymmetric extended objects (super-p-branes) moving in the space--time of arbitrary dimension D (admissible for given $p$) are suggested. The equations of motion are derived,…
A theory of gravity in $d+1$ dimensions is dynamically generated from a theory in $d$ dimensions. As an application we show how $N$ dynamically coupled gravity theories can reduce the effective Planck mass.
The idea of the Gauss map is unified with the concept of branes as hypersurfaces embedded into $D$-dimensional Minkowski space. The map introduces new generalized coordinates of branes alternative to their world vectors $\mathbf{x}$ and…
We analyze homogeneous anisotropic cosmology driven by the dilaton and the self-interacting ``massive'' antisymmetric tensor field which are indispensable bosonic degrees with the graviton in the NS-NS sector of string theories with…
Building on earlier work, we construct linear sigma models for strings on curved spaces in the presence of branes. Our models include an extremely general class of brane-worldvolume gauge field configurations. We explain in an accessible…
We consider type IIB string theory on a seven dimensional orbifold with holonomy in G2. The motivation is to use D1-branes as probes of the geometry. The low energy theory on the D1-brane is a sigma-model with two real supercharges (N =…
We generalise Wesson's procedure, whereby vacuum $(4+1)-$dimensional field equations give rise to $(3+1)-$dimensional equations with sources, to arbitrary dimensions. We then employ this generalisation to relate the usual…
We consider probe p-branes and Dp-branes dynamics in D-dimensional string theory backgrounds of general type. Unified description for the tensile and tensionless branes is used. We obtain exact solutions of their equations of motion and…
Dimensional reduction of generalized gravity theories or string theories generically yields dilaton fields in the lower-dimensional effective theory. Thus at the level of D=4 theories, and cosmology many models contain more than just one…
We study the world-volume effective action of Dp-brane at the tachyonic vacuum which is equivalent to the zero tension limit. Using the Hamiltonian formalism we discuss the algebra of constraints and show that there is a non-trivial ideal…
The gravitational properties of cosmic strings in the Randall-Sundrum brane world scenario are investigated. Using a gauge in which the brane remains straight, the leading order corrections to the metric on the brane are determined. In…
We argue that in ($p+3$)d string theory the existence of NS-NS type $p$-brane with negative tension is essential to obtain background geometry $R_2$ or $R_2 / Z_n$ on the transverse dimensions, and the usual codimension-2 brane solutions…
We study modified gravity theory known as Regge-Teitelboim approach, in which the gravity is represented by dynamics of a surface isometrically embedded in a flat bulk. We obtain some particular solutions of Regge-Teitelboim equations…
We study the dynamics of gravitational lumps. By a lump, we mean a metric configuration that asymptotes to a flat space-time. Such lumps emerge in string theory as strong coupling descriptions of D-branes. We provide a physical argument…
The worldvolume actions of 3+1 dimensional bosonic branes embedded in a five-dimensional bulk space can lead to important effective field theories, such as the DBI conformal Galileons, and may, when the Null Energy Condition is violated,…
We study the role of the brane-induced graviton kinetic term in theories with large extra dimensions. In five dimensions we construct a model with a TeV-scale fundamental Planck mass and a {\it flat} extra dimension the size of which can be…
We propose a formulation of gravity theory in the form of a field theory in a flat space-time with a number of dimensions greater than four. Configurations of the field under consideration describe the splitting of this space-time into a…