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

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 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

Two-Dimensional String Theory, Topological Field Theories and the Deformed Matrix Model

In this paper the $c=1$ string theory is studied from the point of view of topological field theories. Calculations are done for arbitrary genus. A change in the prescription is proposed, which reproduces the results of the $1/x^2$ deformed matrix model. It is proposed that the deformed matrix model is related to a D-series Landau-Ginzburg superpotential.Comment: 20 pages, Latex CERN-TH.7155. Minor typos correcte