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Stefano Giusto

Publications and source records attributed to Stefano Giusto.

59 records · Page 4Linked to original sources

The Kontsevich Connection on the Moduli Space of FZZT Liouville Branes

We point out that insertions of matrix fields in (connected amputated) amplitudes of (generalized) Kontsevich models are given by covariant derivatives with respect to the Kontsevich moduli. This implies that correlators are sections of symmetric products of the (holomorphic) tangent bundle on the (complexified) moduli space of FZZT Liouville branes. We discuss the relation of Kontsevich parametrization of moduli space with that provided by either the (p,1) or the (1,p) boundary conformal field theories. It turns out that the Kontsevich connection captures the contribution of contact terms to open string amplitudes of boundary cosmological constant operators in the (1,p) minimal string models. The curvature of the connection is of type (1,1) and has delta-function singularities at the points in moduli space where Kontsevich kinetic term vanishes. We also outline the extention of our formalism to the c=1 string at self-dual radius and discuss the problems that have to be understood to reconciliate first and second quantized approaches in this case.

hep-th↗

3-charge geometries and their CFT duals

We consider two families of D1-D5-P states and find their gravity duals. In each case the geometries are found to `cap off' smoothly near r=0; thus there are no horizons or closed timelike curves. These constructions support the general conjecture that the interior of black holes is nontrivial all the way up to the horizon.

hep-th↗

Dual geometries for a set of 3-charge microstates

We construct a set of extremal D1-D5-P solutions, by taking appropriate limits in a known family of nonextremal 3-charge solutions. The extremal geometries turn out to be completely smooth, with no horizon and no singularity. The solutions have the right charges to be the duals of a family of CFT microstates which are obtained by spectral flow from the NS vacuum.

hep-th↗

Physical States at the Tachyonic Vacuum of Open String Field Theory

We illustrate a method for computing the number of physical states of open string theory at the stable tachyonic vacuum in level truncation approximation. The method is based on the analysis of the gauge-fixed open string field theory quadratic action that includes Fadeev-Popov ghost string fields. Computations up to level 9 in the scalar sector are consistent with Sen's conjecture about the absence of physical open string states at the tachyonic vacuum. We also derive a long exact cohomology sequence that relates relative and absolute cohomologies of the BRS operator at the non-perturbative vacuum. We use this exact result in conjunction with our numerical findings to conclude that the higher ghost number non-perturbative BRS cohomologies are non-empty.

hep-th↗

The Holomorphic Anomaly of Topological Strings

We show that the BRS operator of the topological string B model is not holomorphic in the complex structure of the target space. This implies that the so-called holomorphic anomaly of topological strings should not be interpreted as a BRS anomaly.

hep-th↗