Black Hole Uncertainties

In this work the quantum theory of two dimensional dilaton black holes is studied using the Wheeler De Witt equation. The solutions correspond to wave functions of the black hole. It is found that for an observer inside the horizon, there are uncertainty relations for the black hole mass and a parameter in the metric determining the Hawking flux. Only for a particular value of this parameter, can both be known with arbitrary accuracy. In the generic case there is instead a relation which is very similar to the so called string uncertainty relation.Comment: 22 pages, Changes: Additions to acknowledgements and reference

The Scattering of Strings in a Black-Hole Background

In this paper, correlation functions of tachyons in the two-dimensional black-hole are studied. The results are shown to be consistent with the prediction of the deformed matrix model.Comment: 10 pages, Latex, CERN-TH.7240/9

The Deformed Matrix Model at Finite Radius and a New Duality Symmetry

The $1/x^{2}$ deformed $c=1$ matrix model is studied at finite radius and non-zero cosmological constant. Calculational techniques are presented and illustrated in some examples. Furthermore, a new kind of $R \rightarrow 1/R$ duality is discovered which mixes different genus.Comment: 11 pages, CERN-TH.7021/9

Type IIB on S3×S3S^{3}\times S^{3} through QQ & PP fluxes

We study a class of orientifold compactifications of type IIB supergravity with fluxes down to 4D in connection with truncations of half-maximal gauged supergravities yielding isotropic STU-models with minimal supersymmetry. In this context, we make use of a group-theoretical approach in order to derive flux-induced superpotentials for different IIB backgrounds. We first review the toroidal case yielding GKP-like superpotentials characterised by their \emph{no-scale} behaviour. We then turn to $S^{3} \times S^{3}$ and $S^{3} \times \mathbb{T}^{3}$, which, surprisingly, give rise to effective descriptions of non-geometric $Q$- and $P$-fluxes through globally geometric non-toroidal compactifications. As a consequence, such constructions break the no-scale symmetry without invoking any non-perturbative effects.Comment: 19 page