arXiv subjects
Publications and source records attributed to Yi-Sheng Wang.
We construct a new category of vector spaces which contains both the standard category of vector spaces and Grassmannians. Its space of objects classifies vector bundles, its space of morphisms classifies bundle isomorphisms, and it can be delooped to obtain the topological $K$-theory spectrum.
In their construction of the topological index for flat vector bundles, Atiyah, Patodi and Singer associate to each flat vector bundle a particular $\mathbb{C/Z}$-$K$-theory class. This assignment determines a map, up to weak homotopy, from $K_{a}\mathbb{C}$, the algebraic $K$-theory space of the complex numbers, to $F_{t,\mathbb{C/Z}}$, the homotopy fiber of the Chern character. In this paper, we give evidence for the conjecture that this map can be represented by an infinite loop map. The result of the paper implies a refined Bismut-Lott index theorem for a compact smooth bundle $E\rightarrow B$ with the fundamental group $π_{1}(E,\ast)$ finite for every point $\ast\in E$.
In this paper, we give a new proof of a well-known theorem due to tom Dieck that the fat realization and Segal's classifying space of an internal category in the category of topological spaces are homotopy equivalent.
We compare the invariants of flat vector bundles defined by Atiyah et al. and Jones et al. and prove that, up to weak homotopy, they induce the same map, denoted by $e$, from the $0$-connective algebraic $K$-theory space of the complex numbers to the homotopy fiber of the Chern character. We examine homotopy properties of this map and its relation with other known invariants. In addition, using the formula for $\tildeξ$-invariants of lens spaces derived from Donnelly's fixed point theorem and the $4$-dimensional cobordisms constructed via relative Kirby diagrams, we recover the formula for the real part of $e$-invariants of Seifert homology spheres given by Jones and Westbury, up to sign. We conjecture that this geometrically defined map $e$ can be represented by an infinite loop map. The results in its companion paper [Wang2] give strong evidence for this conjecture.