Subtleties of the minimax selector

  • Qiaoling Wei

    Université Paris 7, France


In this note, we show that the minimax and maximin critical values of a function quadratic nondegenerate at infinity are equal when defined in homology or cohomology with coefficients in a field. However, by an example of F. Laudenbach, this is not always true for coefficients in a ring and, even in the case of a field, the minimax-maximin depends on the field.

Cite this article

Qiaoling Wei, Subtleties of the minimax selector. Enseign. Math. 59 (2013), no. 3/4, pp. 209–224

DOI 10.4171/LEM/59-3-1