A New Approach To The Local Embedding Theorem Of Cr Structures Of N 4 The Local Solvability For The Operator B In The Abstract Sense

A New Approach to the Local Embedding Theorem of CR-Structures for $n\geq 4$ (The Local Solvability for the Operator $\overline \partial _b$ in the Abstract Sense)

Kuranishi proved that any abstract strongly pseudo convex CR-structure of which real dimension [greater than or equal to] nine can be locally embeddable. In this paper, by introducing a new approach, we improve his result. Namely, we obtain that any abstract strongly pseudo convex CR-structure of which real dimension [greater than or equal to] seven can be locally embeddable.

Several Complex Variables and Complex Geometry, Part III

L2 Approaches in Several Complex Variables

This monograph presents the current status of a rapidly developing part of several complex variables, motivated by the applicability of effective results to algebraic geometry and differential geometry. Special emphasis is put on the new precise results on the L2 extension of holomorphic functions in the past 5 years.In Chapter 1, the classical questions of several complex variables motivating the development of this field are reviewed after necessary preparations from the basic notions of those variables and of complex manifolds such as holomorphic functions, pseudoconvexity, differential forms, and cohomology. In Chapter 2, the L2 method of solving the d-bar equation is presented emphasizing its differential geometric aspect. In Chapter 3, a refinement of the Oka–Cartan theory is given by this method. The L2 extension theorem with an optimal constant is included, obtained recently by Z. Błocki and separately by Q.-A. Guan and X.-Y. Zhou. In Chapter 4, various results on the Bergman kernel are presented, including recent works of Maitani–Yamaguchi, Berndtsson, Guan–Zhou, and Berndtsson–Lempert. Most of these results are obtained by the L2 method. In the last chapter, rather specific results are discussed on the existence and classification of certain holomorphic foliations and Levi flat hypersurfaces as their stables sets. These are also applications of the L2 method obtained during the past 15 years.