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Sylvain Ribault

Publications and source records attributed to Sylvain Ribault.

42 records · Page 3Linked to original sources

H(3)+ correlators from Liouville theory

We prove that arbitrary correlation functions of the H(3)+ model on a sphere have a simple expression in terms of Liouville theory correlation functions. This is based on the correspondence between the KZ and BPZ equations, and on relations between the structure constants of Liouville theory and the H(3)+ model. In the critical level limit, these results imply a direct link between eigenvectors of the Gaudin Hamiltonians and the problem of uniformization of Riemann surfaces. We also present an expression for correlation functions of the SL(2)/U(1) coset model in terms of correlation functions in Liouville theory.

hep-th↗

Branes in the 2D black hole

We present a comprehensive analysis of branes in the Euclidean 2D black hole (cigar). In particular, exact boundary states and annulus amplitudes are provided for D0-branes which are localized at the tip of the cigar as well as for two families of extended D1 and D2-branes. Our results are based on closely related studies for the Euclidean AdS3 model and, as predicted by the conjectured duality between the 2D black hole and the sine-Liouville model, they share many features with branes in Liouville theory. New features arise here due to the presence of closed string modes which are localized near the tip of the cigar. The paper concludes with some remarks on possible applications.

hep-th↗

Cordes et D-branes dans les espaces-temps courbes

This thesis is devoted to the construction and study of D-branes in some curved space-times in string theory. On the one hand, those D-branes are described geometrically as submanifolds subject to Born-Infeld effective dynamics. On the other hand, they can be built microscopically using boundary conformal field theory. We use and compare those two approaches. We also improve them technically : we rewrite Born-Infeld dynamics in a gauge-invariant way, and formulate precise analyticity requirements for the density of open strings on certain D-branes. Our results include the effective description of symmetric D-branes in compact groups, the determination of the complete spectrum of open strings on AdS2 D-branes in AdS3, the exact construction of some D-branes in the cigar SL(2)/U(1), and a geometric description of all D3-branes in NS5-brane backgrounds.

hep-th↗

D3-branes in NS5-brane backgrounds

We study D3-branes in an NS5-branes background defined by an arbitrary 4d harmonic function. Using a gauge-invariant formulation of Born-Infeld dynamics as well as the supersymmetry condition, we find the general solution for the $ω$-field. We propose an interpretation in terms of the Myers effect.

hep-th↗

AdS2 D-branes in AdS3 spacetime

I review some recent progress in understanding the properties of AdS2 branes in AdS3. Different methods - classical string motion, Born-Infeld dynamics, boundary states - are evocated and compared.

hep-th↗

Flux stabilization in compact groups

We consider the Born-Infeld action for symmetry-preserving, orientable D-branes in compact group manifolds. We find classical solutions that obey the flux quantization condition. They correspond to conformally invariant boundary conditions on the world sheet. We compute the spectrum of quadratic fluctuations and find agreement with the predictions of conformal field theory, up to a missing level-dependent truncation. Our results extend to D-branes with the geometry of twined conjugacy classes; they illustrate the mechanism of flux stabilization of D-branes.

hep-th↗