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arXiv · 2607.23230

A Cohomological Obstruction to the Existence of $\phi$-Equivariant Maps

Thales Fernando Vilamaior Paiva
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Abstract

Let $\phi: G\to H$ be a continuous homomorphism between compact Lie groups, let $X$ be a $G$-space, and let $Y$ be an $H$-space. We formulate a filtered change-of-groups obstruction to the existence of a $\phi$-equivariant map $X\to Y$. We apply them to the inclusion of a finite cyclic group into the circle and to homomorphisms between tori acting coordinatewise on products of odd-dimensional spheres.

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Thales Fernando Vilamaior Paiva. 2026-07-25. A Cohomological Obstruction to the Existence of $\phi$-Equivariant Maps. https://arxiv.org/abs/2607.23230

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