Jet isomorphism for conformal geometry

Jet isomorphism theorems for conformal geometry are discussed. A new proof of the jet isomorphism theorem for odd-dimensional conformal geometry is outlined, using an ambient realization of the conformal deformation complex. An infinite order ambient lift for conformal densities in the case in which harmonic extension is obstructed is described. A jet isomorphism theorem for even dimensional conformal geometry is formulated using the inhomogeneous ambient metrics recently introduced by the author and K. Hirachi.Comment: 29 pages, based on lectures delivered at the 2007 Winter School 'Geometry and Physics', Srni, Czech Republic; v.2 corrects typos introduced by arXiv HyperTeX macr

Volume and Area Renormalizations for Conformally Compact Einstein Metrics

This article describes some geometric invariants and conformal anomalies for conformally compact Einstein manifolds and their minimal submanifolds which have recently been discovered via the Anti-de Sitter/Conformal Field Theory correspondence.Comment: 15 pages, to appear Proc. of 19th Winter School in Geometry and Physics, Srni, Czech Rep., Jan. 199

Conformal Powers of the Laplacian via Stereographic Projection

A new derivation is given of Branson's factorization formula for the conformally invariant operator on the sphere whose principal part is the k-th power of the scalar Laplacian. The derivation deduces Branson's formula from knowledge of the corresponding conformally invariant operator on Euclidean space (the k-th power of the Euclidean Laplacian) via conjugation by the stereographic projection mapping.Comment: This is a contribution to the Proceedings of the 2007 Midwest Geometry Conference in honor of Thomas P. Branson, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

Search for star clusters close to the Galactic plane with DENIS

An automated search for star clusters close to the Galactic plane (|b| < 5 deg) was carried out on the Point Source Catalogue of the DENIS survey. 44% of the Galactic plane have been observed and calibrated. The method allowed to retrieve 22 known star clusters and to identify two new ones, not published yet although previously presented in the 2MASS web site as embedded clusters in HII regions. Extinction in the field and in front of the clusters are estimated using a model of population synthesis. We present the method and give the properties of these clusters.Comment: 5 pages, 3 figures, accepted for publication in A&

Scattering Matrix in Conformal Geometry

This paper describes the connection between scattering matrices on conformally compact asymptotically Einstein manifolds and conformally invariant objects on their boundaries at infinity. The conformally invariant powers of the Laplacian arise as residues of the scattering matrix and Branson's Q-curvature in even dimensions as a limiting value. The integrated Q-curvature is shown to equal a multiple of the coefficient of the logarithmic term in the renormalized volume expansion.Comment: 29 pages, 1 figur

Juhl's Formulae for GJMS Operators and Q-Curvatures

Direct proofs are given of Juhl's formulae for GJMS operators and Q-curvatures starting from the original construction of GJMS.Comment: 18 page