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JOURNALS // Algebra and Discrete Mathematics // Archive

Algebra Discrete Math., 2018 Volume 25, Issue 2, Pages 257–268 (Mi adm657)

This article is cited in 1 paper

RESEARCH ARTICLE

Cross-cap singularities counted with sign

Iwona Krzyżanowska

Institute of Mathematics, University of Gdańsk, 80-952 Gdańsk, Wita Stwosza 57, Poland

Abstract: A method for computing the algebraic number of cross-cap singularities for mapping from $m$-dimensional compact manifold with boundary $M\subset \mathbb{R}^m$ into $\mathbb{R}^{2m-1}$, $m$ is odd, is presented. As an application, the intersection number of an immersion $g\colon S^{m-1}(r)\to\mathbb{R}^{2m-2}$ is described as the algebraic number of cross-caps of a mapping naturally associated with $g$.

Keywords: cross-cap, immersion, Stiefel manifold, intersection number, signature.

MSC: 14P25, 57R45, 57R42, 12Y05

Received: 22.09.2015
Revised: 02.03.2018

Language: English



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