Obstructions to Embeddability into Hyperquadrics and Explicit Examples
نویسندگان
چکیده
We give series of explicit examples of Levi-nondegenerate real-analytic hypersurfaces in complex spaces that are not transversally holomorphically embeddable into hyperquadrics of any dimension. For this, we construct invariants attached to a given hypersurface that serve as obstructions to embeddability. We further study the embeddability problem for real-analytic submanifolds of higher codimension and answer a question by Forstnerič.
منابع مشابه
On the Embeddability of Real Hypersurfaces into Hyperquadrics
A well known result of Forstnerić [18] states that most real-analytic strictly pseudoconvex hypersurfaces in complex space are not holomorphically embeddable into spheres of higher dimension. A more recent result by Forstnerić [19] states even more: most real-analytic hypersurfaces do not admit a holomorphic embedding even into a merely algebraic hypersurface of higher dimension, in particular,...
متن کاملEmbedding Obstructions and 4-dimensional Thickenings of 2-complexes
The vanishing of Van Kampen’s obstruction is known to be necessary and sufficient for embeddability of a simplicial n-complex into R for n 6= 2, and it was recently shown to be incomplete for n = 2. We use algebraic-topological invariants of four-manifolds with boundary to introduce a sequence of higher embedding obstructions for a class of 2-complexes in R.
متن کاملOn the AF Embeddability of Crossed Products of AF Algebras by the Integers
This paper is concerned with the question of when the crossed product of an AF algebra by an action of Z is itself AF embeddable. It is well known that quasidiagonality and stable finiteness are hereditary properties. That is, if A and B are C-algebras with A ⊂ B and B has either of these properties, then so does A. Since AF algebras enjoy both of these properties we have that quasidiagonality ...
متن کاملUniversality of Embeddability Relations for Coloured Total Orders
Some examples of Σ 1 1-universal preorders are presented, in the form of various relations of embeddability between countable coloured total orders. As an application, strengthening a theorem of [7], the Σ 1 1-universality of continuous embeddability for dendrites whose branch points have order 3 is obtained.
متن کاملCoarse Embeddability Into
The main purposes of this paper are (1) To survey the area of coarse embeddability of metric spaces into Banach spaces, and, in particular, coarse embeddability of different Banach spaces into each other; (2) To present new results on the problems: (a) Whether coarse non-embeddability into l2 implies presence of expander-like structures? (b) To what extent l2 is the most difficult space to embe...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2007