Absolute parallelism for 2-nondegenerate CR structures via bigraded Tanaka prolongation

A Normal Form for All Levi-nondegenerate Almost Cr Structures

We propose a unified normal form for all Levi-nondegenerate hypersurface type almost CR structures.

Locally homogeneous finitely nondegenerate CR-manifolds

In several areas of mathematics, homogeneous spaces are fundamental objects as they often serve as models for more general objects: Various examples from differential geometry (Riemannian symmetric spaces, principal bundles) and topology (geometric 3-manifolds), to algebraic and complex geometry (uniformization theorems, flag manifolds) etc. underline the importance of spaces, furnished with a ...

Searching for More Absolute Cr-epic Spaces

We continue our examination of absolute CR -epic spaces, or spaces with the property that any embedding induces an epimorphism, in the category of commutative rings, between their rings of continuous functions. We examine more closely the deleted plank construction, which generalizes the Dieudonné construction, and yields absolute CR -epic spaces which are not Lindelöf. For the Lindelöf case, a...

Bigraded Cohomology of Z/2-equivariant Grassmannians

Global Structures on CR Manifolds via Nash Blow-ups

A generic compact real codimension two submanifold X of Cn+2 will have a CR structure at all but a finite number of points (failing at the complex jump points J). The main theorem of this paper gives a method of extending the CR structure on the non-jump points X − J to the jump points. We examine a Gauss map from X − J to an appropriate flag manifold F and take the closure of the graph of this...