Page 1 Progress in Mathematics 275 Andreas Juhl Families of Conformally Covariant
Differential Operators, Q-Curvature and Holography Page 2 BIRKHAUSER Page 3 Progress …

A bstract We present a new formalism to solve the kinematical constraints due to Weyl
invariance for CFTs in curved backgrounds and/or non-trivial states, and we apply it to …

A new definition of canonical conformal differential operators P k (k= 1, 2,...), with leading
term ak th power of the Laplacian, is given for conformally Einstein manifolds of any …

An almost Einstein manifold satisfies equations which are a slight weakening of the Einstein
equations; Einstein metrics, Poincaré–Einstein metrics, and compactifications of certain …

We introduce a fourth order CR invariant operator on pluriharmonic functions on a three-
dimensional CR manifold, generalizing to the abstract setting the operator discovered by …

On conformally compact manifolds of arbitrary signature, we use conformal geometry to
identify a natural (and very general) class of canonical boundary problems. It turns out that …

A bstract Ambitwistor strings are chiral (holomorphic) strings whose target is the space of
complex null geodesics, ambitwistor space. We introduce twistor representations of …

We study higher form Proca equations on Einstein manifolds with boundary data along
conformal infinity. We solve these Laplace-type boundary problems formally, and to all …

We develop the natural tractor calculi associated to conformal and CR structures as a
fundamental tool for the study of Fefferman's construction of a canonical conformal class on …

We establish an algorithm which computes formulae for the CR GJMS operators, the $
P^\prime $-operator, and the $ Q^\prime $-curvature in terms of CR tractors. When applied to …