On Fredholm Index, Transversal Approximations and Quillen's Geometric Complex Cobordism of Hilbert Manifolds with some Applications to Flag Varieties of Loop Groups

On smooth Chas-Sullivan loop product in Quillen's geometric complex cobordism of Hilbert manifolds

In \cite{baker-ozel}, by using Fredholm index we developed a version of Quillen's geometric cobordism theory for infinite dimensional Hilbert manifolds. This cobordism theory has a graded group structure under topological union operation and has push-forward maps for complex orientable Fredholm maps. In \cite{cenap-isr}, by using Quinn's Transversality Theorem \cite{Quinn}, it has been shown that this cobordism theory has a graded ring structure under transversal intersection operation and has pull-back maps for smooth maps. It has been shown that the Thom isomorphism in this theory was satisf…

Topological categories related to Fredholm operators: I. Classifying spaces

In 1970s Segal outlined proofs of two theorems relating spaces of Fredholm and self-adjoint Fredholm operators with Quillen's constructions used to define higher algebraic K-theory. In the present paper we provide detailed proofs of these theorems of Segal (different from the ones outlined by Segal) and then transplant some further ideas of Quillen to the real of Fredholm and self-adjoint Fredholm operators. The main results may be considered as partial analogues of the equivalence of Quillen's two definition of higher algebraic K-theory. Along the way we relate spaces of Fredholm and self-adj…

Fundamental groups, homology equivalences and one-sided h-cobordisms

We give a sufficient and necessary condition of the fundamental group homomorphism of a map between manifolds to induce homology equivalences. Moreover, a classification of one-sided h-cobordism of manifolds up to diffeomorphisms is obtained, based on Quillen's plus construction with Whitehead torsions.

指标为1的真Fredholm映射的同伦分类

The homotopy classification of proper Fredholm maps of index one

本研究在前期已完成非正指标真Fredholm映射同伦分类的基础上，引入新的数值不变量，完成了单连通希尔伯特流形到其模型空间的指标为1的真Fredholm映射的同伦类计算。

Hilbert stratifolds and a Quillen type geometric description of cohomology for Hilbert manifolds

In this paper we use tools from differential topology to give a geometric description of cohomology for Hilbert manifolds. Our model is Quillen's geometric description of cobordism groups for finite dimensional smooth manifolds \cite{Q}. Quillen stresses the fact that this construction allows the definition of Gysin maps for "oriented" proper maps. For finite dimensional manifolds one has a Gysin map in singular cohomology which is based on Poincaré duality, hence it is not clear how to extend it to infinite dimensional manifolds. But perhaps one can overcome this difficulty by giving a Quille…

On the homotopy classification of proper Fredholm maps into a Hilbert space

We classify the homotopy classes of proper Fredholm maps from an infinite dimensional Hilbert manifold into its model space in terms of a suitable version of framed cobordism. Our construction is an alternative approach to the classification introduced by Elworthy and Tromba in 1970 and does not make use of further structures on the ambient manifold, such as Fredholm structures. In the special case of index zero, we obtain a complete classification involving the Caccioppoli-Smale mod 2 degree and the absolute value of the oriented degree.