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arXiv 2011.132452020-11math.RT

Stiefel Whitney Classes for Real representations of $\mathrm{GL}_2(\mathbb{F}_q)$

Jyotirmoy Ganguly, Rohit Joshi

英文摘要：

We compute the total Stiefel Whitney class for a real representation $π$ of $\mathrm{GL}_2(\mathbb{F}_q)$, where $q$ is odd. The obstruction class of $π$ is defined to be the Stiefel Whitney class of lowest positive degree that does not vanish. We provide an expression for the obstruction class of $π$ in terms of its character values if $\detπ=1$.

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