tailieunhanh - Báo cáo hóa học: " A BASE-POINT-FREE DEFINITION OF THE LEFSCHETZ INVARIANT"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: A BASE-POINT-FREE DEFINITION OF THE LEFSCHETZ INVARIANT | A BASE-POINT-FREE DEFINITION OF THE LEFSCHETZ INVARIANT VESTA COUFAL Received 30 November 2004 Accepted 21 July 2005 In classical Lefschetz-Nielsen theory one defines the Lefschetz invariant L f of an endomorphism f of a manifold M. The definition depends on the fundamental group of M and hence on choosing a base point e M and a base path from to f . At times it is inconvenient or impossible to make these choices. In this paper we use the fundamental groupoid to define a base-point-free version of the Lefschetz invariant. Copyright 2006 Vesta Coufal. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. Introduction In classical Lefschetz fixed point theory 3 one considers an endomorphism f M M of a compact connected polyhedron M. Lefschetz used an elementary trace construction to define the Lefschetz invariant L f e Z. The Hopf-Lefschetz theorem states that if L f 0 then every map homotopic to f has a fixed point. The converse is false. However a converse can be achieved by strengthening the invariant. To begin one chooses a base point of M and a base path T from to f . Then using the fundamental group and an advanced trace construction one defines a Lefschetz-Nielsen invariant L f T which is an element of a zero-dimensional Hochschild homology group 4 . Wecken proved that when M is a compact manifold of dimension n 2 L f T 0 if and only if f is homotopic to a map with no fixed points. We wish to extend Lefschetz-Nielsen theory to a family of manifolds and endomorphisms that is a smooth fiber bundle p E B together with a map f E E such that p p f. One problem with extending the definitions comes from choosing base points in the fibers that is a section s of p and the fact that f is not necessarily fiber homotopic to a map which fixes the base points as is the case for a single path connected space and a .

TÀI LIỆU LIÊN QUAN
TÀI LIỆU MỚI ĐĂNG
crossorigin="anonymous">
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.