In the context of integrability in AdS/CFT correspondence, we construct the Green-Schwarz-Metsaev-Tseytlin supersting in the S(5) x R(1) sector, from a set of physical particles on a circle in the integrable 1+1D sigma-model with Zamolodchikov's S-matrix. We reproduce, in the limit of high density of the particles, all finite gap KMMZ solutions for classical strings and the quantum AFS string Bethe ansatz equations, as an approximation to our construction.

I will discuss the construction supergravity plus branes solutions dual to 4d N=1 SQCD with a quartic superpotential. The geometries depend on the ratio Nf/Nc which is kept of order one. I will show how some field theory features like R-symmetry breaking, Seiberg duality, Wilson loops and pair creation, running of couplings and domain walls are encoded in the solutions.

I will describe a new formulation of Witten's open bosonic string field theory based on non-standard world-sheet parametrization. The theory dramatically simplifies and the long-searched-for tachyon vacuum can be explicitly constructed. This allows us to find a proof for one of the Sen's conjectures relating the energy of the tachyon solution to the tension of the D25-brane.

We consider classical strings propagating in a background generated by a sequence of TsT transformations. We describe a general procedure to derive the Green-Schwarz action for strings. We show that the U(1) isometry variables of the TsT-transformed background are related to the isometry variables of the initial background in a universal way independent of the details of the background. This allows us to prove that strings in the TsT-transformed background are described by the Green-Schwarz action for strings in the initial background subject to twisted boundary conditions. Our construction implies that a TsT transformation preserves integrability properties of the string sigma model. We discuss in detail type IIB strings propagating in the TsT-transformed AdS(5) x S(5) space-time and find the twisted boundary conditions for bosons and fermions. We also discuss string zero modes whose dynamics is governed by a fermionic generalization of the integrable Neumann model.

In the first part of the talk we discuss how to construct geometries sourced by branes carrying general condensates. As an example we consider fundamental strings carring fermion bilinear condensates. Dualizing to the D1-D5 system these correspond to the missing geometries needed to account for all black hole microstates in the fuzzball conjecture. In the second half of the talk we discuss new results in extracting field theory data from (asymptotically AdS) geometries. These methods can be used to show that the D1-D5 geometries do indeed correspond to R vacua with all the requisite properties.

We investigate quaternionic (especially hyperkahler) analogues of the symplectic cut construction. In low dimensions this can be interpreted as a adding a brane to a hyperkahler manifold.

Meeting of the IoP Mathematical and Theoretical Physics Group, to be held at Imperial College on the 10th and 11th of March. Registration requested. Details can be found here: http://groups.iop.org/MP/perspectives.html

I will review the recent developments in topological membrane theory. In particular I will discuss the formulation of topological membrane theory on G2-manifolds and its role in the topological M-theory. The reduction to topological strings will be presented.

We show the existence of an N=1 supersymmetric vacuum in string theory whose observable sector has exactly the matter content of the MSSM without exotic particles and vector-like pairs of any type. This is done so by compactifying the E_8 x E_8 heterotic string on a Calabi-Yau threefold endowed with an SU(4) vector bundle which has been constructed after extensive search. In addition, we discuss the Yukawa couplings and Higgs mu-terms in this model.

In the moduli stabilization program a la KKLT, the dilaton and the complex structure moduli are fixed via background 3-form fluxes, whereas the Kaehler moduli are fixed through non-perturbative effects such as Euclidean D3-brane instantons and gaugino condensation. After briefly introducing toroidal orbifolds, I will discuss some issues of stability and then turn to moduli stabilization in resolved toroidal type IIB orientifolds. The main emphasis will be on the resolution of the singularities via blow-ups, gluing together the local patches to obtain a smooth Calabi-Yau, and the topologies of the exceptional divisors.

I review what one has learned about SU(N) gauge theories from lattice calculations. I will discuss the mass spectrum, finite T phase transitions, k-strings, topology and strong-to-weak coupling transitions as well as the basic question of how close N=3 is to N=infinity.

We study a stationary black brane in M-superstring theory. Assuming BPS-type relations between the first-order derivatives of metric functions, we present general stationary black brane solutions with a traveling wave for the Einstein equations in D-dimensions. The solutions are given by a few independent harmonic equations (and plus the Poisson equation). General solutions are constructed by superposition of a complete set of those harmonic functions. Using the hyperspherical coordinate system for a conformally flat base space, we explicitly give the solutions in 11-dimensional M-theory for the case with M2-M5 intersecting branes and a traveling wave. Compactifying these solutions into five dimensions, we show that these solutions include the BMPV black hole and the Brinkmann wave solution, and those extension to non-BPS ones. We also find new solutions similar to the Brinkmann wave. We prove that the solutions preserve the one eigth supersymmetry if the gravi-electromagnetic field, which is a rotational part of gravity, is self-dual. We also discuss non-spherical black objects (e.g., a ring topology and an elliptical shape) by use of other curvilinear coordinates.

I will discuss the dynamics of Nambu--Goto strings with junctions at which three strings meet, in particular, the process of intercommuting of two straight strings, in which they exchange partners but become joined by a third string. I shall show that there are important kinematical constraints on this process. The exchange cannot occur if the strings meet with very large relative velocity. In the case of non-abelian strings, there is also a possibility that they can get locked, unable to separate in any direction. This may have important implications for the evolution of cosmic superstring networks and non-abelian string networks.