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arXiv math/0403421math.AT
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Lefschetz-Hopf定理和莱夫谢茨数的公理

The Lefschetz-Hopf theorem and axioms for the Lefschetz number

Martin Arkowitz, Robert F. Brown

摘要:

本文证明了约化的莱夫谢茨数,即莱夫谢茨数减1,是紧致多面体自映射上唯一的整值函数L,它在同伦类上是常数,使得(1)L(fg)= L(gf),对f:X -->Y和g:Y -->X;(2)若(f_1,f_2,f_3)是上纤维序列到自身的映射,则L(f_2)= L(f_1)+ L(f_3); + 度(p_k f e_k)),其中f是k个圆的楔形的映射,e_r是圆到第r个被加数中的包含,p_r是到第r个被加数上的投影。设f:X -->X是多面体的自映射,I(f)是f在所有X上的不动点指数,则证明了I减1满足上述公理.这给出了正规化定理的一个新证明:如果f:X -->X是多面体的自映射,则I(f)等于f的莱夫谢茨数.这个结果等价于Lefschetz-Hopf定理:如果f:X ->X是一个具有有限个不动点的有限单纯复形的自映射,每个不动点位于一个极大单纯形中,那么f的莱夫谢茨数是f的所有不动点的指数之和。

英文摘要:

The reduced Lefschetz number, that is, the Lefschetz number minus 1, is proved to be the unique integer-valued function L on selfmaps of compact polyhedra which is constant on homotopy classes such that (1) L(fg) = L(gf), for f:X -->Y and g:Y -->X; (2) if (f_1, f_2, f_3) is a map of a cofiber sequence into itself, then L(f_2) = L(f_1) + L(f_3); (3) L(f) = - (degree(p_1 f e_1) + ... + degree(p_k f e_k)), where f is a map of a wedge of k circles, e_r is the inclusion of a circle into the rth summand and p_r is the projection onto the rth summand. If f:X -->X is a selfmap of a polyhedron and I(f) is the fixed point index of f on all of X, then we show that I minus 1 satisfies the above axioms. This gives a new proof of the Normalization Theorem: If f:X -->X is a selfmap of a polyhedron, then I(f) equals the Lefschetz number of f. This result is equivalent to the Lefschetz-Hopf Theorem: If f: X -->X is a selfmap of a finite simplicial complex with a finite number of fixed points, each lying in a maximal simplex, then the Lefschetz number of f is the sum of the indices of all the fixed points of f.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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