Scattering from an AdS_3 bubble and an exact AdS_3

We investigate the close relationship between the potential and absorption cross section for test fields in an AdS$_3$ bubble(a 5D black hole) and an exact AdS$_3$. There are two solutions in type IIB string theory: an AdS$_3$ bubble corresponds to the dilatonic solution, while an exact AdS$_3$ is the non-dilatonic solution. In order to obtain the cross section for an AdS$_3$ bubble, we introduce the \{out\}-state scattering picture with the AdS$_3$-AFS matching procedure. For an exact AdS$_3$, one considers the \{in\}-state scattering picture with the AdS$_3$-AdS$_3$ matching. Here the non-normalizable modes are crucially taken into account for the matching procedure. It turns out that the cross sections for the test fields in an AdS$_3$ bubble take the same forms as those in an exact AdS$_3$. This suggests that in the dilute gas and the low energy limits, the S-matrix for an AdS$_3$ bubble can be derived from an exact AdS$_3$ space.Comment: revised version to appear in Physical Review D, 26 pages with embedded 5 EPS figures in RevTex forma

Employment subsidies - A fast lane from unemployment to work?

The treatment effect of a Swedish employment subsidy is estimated using exact covariate-matching and instrumental variables methods. Our estimates suggest that the programme had a positive treatment effect for the participants. We also show how non-parametric methods can be used to estimate the time profile of treatment effects as well as how to estimate the effect of entering the programme at different points in time in the unemployment spell. Our main results are derived using matching methods. However, as a sensitivity test, we apply instrumental variables difference-in-difference methods. These estimates indicate that our matching results are robustEvaluation; employment subsidies; exact covariate-matching

Heavy quarkonium decays and transitions in the language of effective field theories

Heavy quarkonium decays and transitions are discussed in the framework of non-relativistic effective field theories. Emphasis is put on the matching procedure in the non-perturbative regime. Some exact results valid for the magnetic dipole couplings are discussed.Comment: 7 pages; Talk given at Hadron 05, Rio de Janeiro, August 22-26, 2005 and QCD@Work 2005, Conversano, June 16-20, 200

Matching Exact Results and One-Instanton Predictions in N=2 Supersymmetric SU(N) Theories

A one-instanton level test is performed for the proposed reparameterisation scheme matching the conjectured exact low energy results and instanton predictions for N=2 supersymmetric SU(N) gauge theories with 2N massless fundamental matter hypermultiplets across the entire quantum moduli space. The constants within the scheme which ensure agreement between the exact results and the instanton predictions for general N are derived. This constitutes a non-trivial test of the scheme, which eliminates the discrepancies arising when the two sets of results are compared.Comment: 9 pages, LaTeX; reformatte