Related papers: String instanton in AdS(4)xCP(3)
Type II supergravity admits an AdS(3) x S(2) x S(2) x T(3) solution with fluxes depending on several free parameters. We determine the constraints on these parameters imposed by the requirement of (classical) integrability of the…
We show that $QCD_2$ with adjoint fermions involves instantons due to nontrivial $\pi_1[SU(N)/Z_N]~=~Z_N$. At high temperatures, quasiclassical approximation works and the action and the form of effective (with account of quantum…
We derive a BPS-type bound for four-dimensional Born-Infeld action with constant B field background. The supersymmetric configuration saturates this bound and is regarded as an analog of instanton in U(1) gauge theory. Furthermore, we find…
We describe the structure of string vacuum states in the supersymmetric matrix model for M theory compactified on a circle in the large-N limit. We show that the theory admits topological instanton field configurations which at…
We consider fixing the bosonic light-cone gauge for string in AdS in the phase space framework, i.e. by choosing $x^+ = \tau$, and by choosing $\sigma$ so that $P^+$ is distributed uniformly (its density is independent of $\sigma$). We…
We find the full interacting Lagrangian and Hamiltonian for quantum strings in a near plane wave limit of AdS_4 x CP^3. The leading curvature corrections give rise to cubic and quartic terms in the Lagrangian and Hamiltonian that we compute…
We study semiclassical string solutions on the 1/2 BPS geometry of type IIB string theory characterized by concentric rings on the boundary plane. We consider both folded rotating strings carrying nonzero R-charge and circular pulsating…
We explore the non-perturbative aspects of $c=1$ string with compactified Euclidean time, its $0+0$ dimensional matrix model duals (at self-dual radius), and $0+1$ dimensional Matrix Quantum Mechanics (free fermion) description. We…
We first focus on the finite-gap formalism for type IIB strings in AdS_3 x S^1, which allows to encode the semiclassical spectrum of a very large family of string solutions in a Riemann surface, the spectral curve. Then, we show that, in…
Three-dimensional string theories with 16 supersymmetries are believed to possess a non-perturbative U-duality symmetry $SO(8,24,\Zint)$. By covariantizing the heterotic one-loop amplitude under U-duality, we propose an exact expression for…
Using instanton calculus we check, in the weak coupling region, the nonperturbative relation $$ <\Tr\phi^2>=i\pi\left(\cf-{a\over 2} {\partial\cf\over\partial a}\right)$$ obtained for a N=2 globally supersymmetric gauge theory. Our…
The D-instanton expansion of the topological B-model on the supermanifold CP(3|4) reproduces the perturbative expansion of N=4 Super Yang-Mills theory. In this paper we consider orbifolds in the fermionic directions of CP(3|4). This…
A class of D-branes for the type IIB plane-wave background is considered that preserve half the dynamical supersymmetries of the light-cone gauge. The D-branes of this type are the euclidean (or instantonic) (0,0), (0,4) and (4,0) branes…
The (I)nstantonic strings are described as extended states occupying a flat (isometry) direction on the multiple M5-brane world-volume. These are constituted by 4-dimensional gauge instantons and 2-dimensional chiral axion. In this light we…
We interpret a class of 4k-dimensional instanton solutions found by Ward, Corrigan, Goddard and Kent as four-dimensional instantons at angles. The superposition of each pair of four-dimensional instantons is associated with four angles…
The non-linear nature of string theory on non-trivial backgrounds related to the AdS/CFT correspondence suggests to look for simplifications. Two such simplifications proved to be useful in studying string theory. These are the pp-wave…
We study various aspects of four dimensional Einstein-Maxwell multicentred gravitational instantons. These are half-BPS Riemannian backgrounds of minimal N=2 supergravity, asymptotic to R^4, R^3 x S^1 or AdS_2 x S^2. Unlike for the…
This is a comprehensive review of the worldsheet techniques for the quantization of type IIB superstring theory on the AdS_5 x S^5 background, using the pure spinor formalism. Particular emphasis is devoted to AdS/CFT applications, with…
We construct IIA GS superstring action on the ten-dimensional pp-wave background, which arises as the compactification of eleven-dimensional pp-wave geometry along the isometry direction. The background geometry has 24 Killing spinors and…
We consider all 1/2 BPS excitations of $AdS \times S$ configurations in both type IIB string theory and M-theory. In the dual field theories these excitations are described by free fermions. Configurations which are dual to arbitrary…