On the Canonical Equivalence of Liouville and Free Fields

We obtain the parity invariant generating functional for the canonical transformation mapping the Liouville theory into a free scalar field and explain how it is related to the pseudoscalar transformationComment: 8 pages, Latex, Important earlier work by G.P. Jordadze acknowledge

Formation of Black Holes in Topologically Massive Gravity

We present an exact solution in 3-dimensional topologically massive gravity with negative cosmological constant which dynamically interpolates between a past horizon and a chiral AdS pp-wave. Similarly, upon time reversal, one obtains an AdS pp-wave with a future event horizonComment: Improved presentation. Extended discussion of linear stability and regularity of the metric. Added reference

Fiscal Federalism and Optimum Currency Areas: Evidence for Europe From the United States

The main goal of this paper is to estimate to what extent the federal government of the United States insures member states against regional income shocks. We find that a one dollar reduction in a region's per capita personal income triggers a decrease in federal taxes of about 34 cents and an increase in federal transfers of about 6 cents. Hence, the final reduction in disposable per capita income is on the order of 60 cents. That is, between one third and one half of the initial shock is absorbed by the federal government. The much larger reaction of taxes than transfers to these regional imbalances reflects the fact that the main mechanism at work is the federal income tax system which in turn means that the stabilization process is automatic rather than specifically designed each time there is a cyclical movement in income. Some economists may want to argue that this regional insurance scheme provided by the federal government is an important reason why the system of fixed exchange rates that exists within the United States today has survived without major problems. Under this view, the creation of a European Central Bank that issues unified European currency without the simultaneous introduction (or expansion) of a fiscal federalist system could put the project at risk. Rough calculations of the impact of the existing European tax system on regional income suggests that a one dollar shock to regional GDP will reduce tax payments to the EEC government by half a cent!. Hence, the current European tax system has a long way to go before it reaches the 34 cents of the U.S. Federal Government.

Scaling tests with dynamical overlap and rooted staggered fermions

We present a scaling analysis in the 1-flavor Schwinger model with the full overlap and the rooted staggered determinant. In the latter case the chiral and continuum limit of the scalar condensate do not commute, while for overlap fermions they do. For the topological susceptibility a universal continuum limit is suggested, as is for the partition function and the Leutwyler-Smilga sum rule. In the heavy-quark force no difference is visible even at finite coupling. Finally, a direct comparison between the complete overlap and the rooted staggered determinant yields evidence that their ratio is constant up to $O(a^2)$ effects.Comment: 28 pages, 20 figures containg 37 graphs. v2: 6 new references, 2 new footnotes (to match published version

The Schwinger Model on a circle: relation between Path Integral and Hamiltonian approaches

We solve the massless Schwinger model exactly in Hamiltonian formalism on a circle. We construct physical states explicitly and discuss the role of the spectral flow and nonperturbative vacua. Different thermodynamical correlation functions are calculated and after performing the analytical continuation are compared with the corresponding expressions obtained for the Schwinger model on the torus in Euclidean Path Integral formalism obtained before.Comment: 40 page

Brief Resume of Seiberg-Witten Theory

Talk presented by the second author at the Inaugural Coference of the Asia Pacific Center for Theoretical Physics, Seoul, June 1996. The purpose of this note is to give a resume of the Seiberg-Witten theory in the simplest possible mathematical terms.Comment: 10 pages, LaTe