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MATHEMATICS
Bruhat numbers of a strong Morse function
P. E. Pushkar'ab, M. Tyomkinac a National Research University Higher School of Economics, Moscow, Russia
b Independent University of Moscow, Moscow, Russia
c Dartmouth College, Hanover, USA
Abstract:
Let $f$ be a Morse function on a manifold M such that all its critical values are pairwise distinct. Given such a function (together with a certain choice of orientations) and a field $\mathbb F$, we construct a set of nonzero elements of the field, which are called Bruhat numbers. Under certain acyclicity conditions on $M$, the alternating product of all the Bruhat numbers does not depend on $f$ (up to sign); thus, it is an invariant of the manifold. For any typical one-parameter family of functions on $M$, we provide a relation that links the Bruhat numbers of the boundary functions of the family with the number of bifurcations happening along a path in the family. This relation generalizes the result from [1].
Keywords:
Morse theory, Cerf theory, topology of manifolds.
Citation:
P. E. Pushkar', M. Tyomkin, “Bruhat numbers of a strong Morse function”, Dokl. RAN. Math. Inf. Proc. Upr., 507 (2022), 57–60; Dokl. Math., 106:3 (2022), 454–457
Linking options:
https://www.mathnet.ru/eng/danma319 https://www.mathnet.ru/eng/danma/v507/p57
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Abstract page: | 88 | References: | 30 |
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