Commuting involutions whose fixed point set consists of two special components

Pedro L. Q. Pergher¹ ; Rogério de Oliveira²

¹Departamento de Matemática Universidade Federal de São Carlos Caixa Postal 676 São Carlos, SP 13565-905, Brazil
²Departamento de Ciências Exatas Universidade Federal de Mato Grosso do Sul Caixa Postal 210 Três Lagoas, MS 79603-011, Brazil

Fundamenta Mathematicae, Tome 201 (2008) no. 3, pp. 241-259

Résumé

Let $F^n$ be a connected, smooth and closed $n$-dimensional manifold. We call $F^n$ a manifold with property $\mathcal{H}$ when it has the following property: if $N^m$ is any smooth closed $m$-dimensional manifold with $m>n$ and $T:N^m \to N^m$ is a smooth involution whose fixed point set is $F^n$, then $m=2n$. Examples of manifolds with this property are: the real, complex and quaternionic even-dimensional projective spaces $RP^{2n}$, $CP^{2n}$ and $HP^{2n}$, and the connected sum of $RP^{2n}$ and any number of copies of $S^n \times S^n$, where $S^n$ is the $n$-sphere and $n$ is not a power of $2$. In this paper we describe the equivariant cobordism classification of smooth actions $(M^m; {\mit\Phi})$ of the group $Z_2^k$ on closed smooth $m$-dimensional manifolds $M^m$ for which the fixed point set of the action consists of two components $K$ and $L$ with property $\mathcal{H}$, and where ${\rm dim}(K) {\rm dim}(L)$. The description is given in terms of the set of equivariant cobordism classes of involutions fixing $K \cup L$.

Détail

DOI : 10.4064/fm201-3-3

Keywords: connected smooth closed n dimensional manifold call manifold property mathcal has following property smooth closed m dimensional manifold smooth involution whose fixed point set examples manifolds property real complex quaternionic even dimensional projective spaces connected sum number copies times where n sphere power paper describe equivariant cobordism classification smooth actions mit phi group closed smooth m dimensional manifolds which fixed point set action consists components property mathcal where dim dim description given terms set equivariant cobordism classes involutions fixing cup