English
Related papers

Related papers: Classification of 3-dimensional isolated rational …

200 papers

We introduce the concept of finitely coloured equivalence for unital *-homomorphisms between C*-algebras, for which unitary equivalence is the 1-coloured case. We use this notion to classify *-homomorphisms from separable, unital, nuclear…

Operator Algebras · Mathematics 2019-04-24 Joan Bosa , Nathanial P. Brown , Yasuhiko Sato , Aaron Tikuisis , Stuart White , Wilhelm Winter

Singular actions on C*-algebras are automorphic group actions on C*-algebras, where the group need not be locally compact, or the action need not be strongly continuous. We study the covariant representation theory of such actions. In the…

Operator Algebras · Mathematics 2020-07-27 Daniel Beltita , Hendrik Grundling , Karl-Hermann Neeb

In this paper, we describe the homotopy type of the homotopy fixed point sets of $S^3$-actions on rational spheres and complex projective spaces, and provide some properties of $S^1$-actions on a general rational complex.

Algebraic Topology · Mathematics 2022-10-26 Yanlong Hao , Xiugui Liu , Qianwen Sun

A complex filling of a CR manifold is said to be equivariant with respect to a CR action if the action extends to a smooth action by biholomorphisms on the whole filling. Under a noncompactness condition for the action, we describe all…

Differential Geometry · Mathematics 2009-01-05 Benoit Kloeckner

It is shown that a formal mapping between two real-analytic hypersurfaces in complex space is convergent provided that neither hypersurface contains a nontrivial holomorphic variety. For higher codimensional generic submanifolds,…

Complex Variables · Mathematics 2007-05-23 M. S. Baouendi , P. Ebenfelt , L. P. Rothschild

A general class of singular real hypersurfaces, called subanalytic, is defined. For a subanalytic hypersurface M in C^n, Cauchy-Riemann (or simply CR) functions on M are defined, and certain properties of CR functions discussed. In…

Complex Variables · Mathematics 2009-11-20 Debraj Chakrabarti , Rasul Shafikov

Complex supermanifold structures being deformations of the exterior algebra of a holomorphic vector bundle, have been parametrized by orbits of a group on non-abelian cohomology by P. Green. For the case of odd dimension $4$ and $5$ an…

Complex Variables · Mathematics 2016-01-28 Matthias Kalus

In this paper the detailed classification of three-dimensional exceptional canonical hypersurface singularities which don't satisfy the condition of well-formedness is given. This result completes the classification of three-dimensional…

Algebraic Geometry · Mathematics 2007-05-23 Sergey Kudryavtsev

A question of B. Teissier, inspired by a previous problem of R. Thom, asks whether for any germ of complex analytic hypersurface there exists a germ of complex algebraic hypersurface with the same topological type. Up to now only the case…

Algebraic Geometry · Mathematics 2010-03-01 Javier Fernandez de Bobadilla

We give a complete solution to the local classification program of higher rank partially hyperbolic algebraic actions. We show $C^\infty$ local rigidity of abelian ergodic algebraic actions for symmetric space examples, twisted symmetric…

Dynamical Systems · Mathematics 2025-03-20 Zhenqi Jenny Wang

We classify cohomogeneity one actions on smooth, simply connected, closed manifolds with the rational cohomology of a sphere. In particular, we show that such a manifold is diffeomorphic to a sphere, a Brieskorn variety, the Wu manifold…

Differential Geometry · Mathematics 2021-08-26 Jason DeVito

We give a characterization of closed, simply connected, rationally elliptic 6-manifolds in terms of their rational cohomology rings and a partial classification of their real cohomology rings. We classify rational, real and complex homotopy…

Algebraic Topology · Mathematics 2015-04-10 Martin Herrmann

We use methods from the cohomology of groups to describe the finite groups which can act freely and homologically trivially on closed 3-manifolds which are rational homology spheres.

Algebraic Topology · Mathematics 2019-08-16 Alejandro Adem , Ian Hambleton

In this paper, we show how to construct a special class of ruled hypersurfaces in the nonflat complex space forms $\mathbb{CP}^n$ and $\mathbb{C}H^n$. This is done by taking an arbitrary smooth curve in a totally geodesic (complex)…

Differential Geometry · Mathematics 2026-05-25 Thomas A. Ivey , Patrick J. Ryan

Building on recent work of Robertson and Steger, we associate a C*-algebra to a combinatorial object which may be thought of as a higher rank graph. This C*-algebra is shown to be isomorphic to that of the associated path groupoid.…

Operator Algebras · Mathematics 2007-05-23 Alex Kumjian , David Pask

We classify the rational differential 1-forms with simple poles and simple zeros on the Riemann sphere according to their isotropy group; when the 1-form has exactly two poles the isotropy group is isomorphic to $\mathbb{C}^{*}$, namely…

Geometric Topology · Mathematics 2018-11-13 Alvaro Alvarez-Parrilla , Martín Eduardo Frías-Armenta , Carlos Yee-Romero

We study the rational homotopy types of classifying spaces of automorphism groups of smooth simply connected manifolds of dimension at least five. We give dg Lie algebra models for the homotopy automorphisms and the block diffeomorphisms of…

Algebraic Topology · Mathematics 2020-01-16 Alexander Berglund , Ib Madsen

We study singular real-analytic Levi-flat hypersurfaces in complex projective space. We define the rank of an algebraic Levi-flat hypersurface and study the connections between rank, degree, and the type and size of the singularity. In…

Complex Variables · Mathematics 2012-02-29 Jiri Lebl

We further the classification of rational surface singularities. Suppose $(S, \mathfrak{n}, \mathcal{k})$ is a strictly Henselian regular local ring of mixed characteristic $(0, p > 5)$. We classify functions $f$ for which $S/(f)$ has an…

Algebraic Geometry · Mathematics 2022-08-18 Javier Carvajal-Rojas , Linquan Ma , Thomas Polstra , Karl Schwede , Kevin Tucker

We show that if X is any proper complex variety, there is a weight decomposition on the real schematic homotopy type, in the form of an algebraic G_m-action. This extends to a real Hodge structure, in the form of a discrete C^*-action, such…

Algebraic Geometry · Mathematics 2010-05-28 J. P. Pridham