Orbifold bordism and duality for finite orbispectra

TL;DR

This paper develops a homotopy category for finite orbispectra, establishing a duality that connects cobordism theories with orbifold bordism groups, extending classical isomorphisms to the orbifold setting.

Contribution

It constructs the stable homotopy category of finite orbispectra and introduces a duality extending Spanier--Whitehead duality to this context.

Findings

Established a contravariant involution extending duality.

Connected homotopical cobordism theories to orbifold bordism groups.

Extended classical Pontryagin--Thom isomorphism to orbifolds.

Abstract

We construct the stable (representable) homotopy category of finite orbispectra, whose objects are formal desuspensions of finite orbi-CW-pairs by vector bundles and whose morphisms are stable homotopy classes of (representable) relative maps. The stable representable homotopy category of finite orbispectra admits a contravariant involution extending Spanier--Whitehead duality. This duality relates homotopical cobordism theories (cohomology theories on finite orbispectra) represented by global Thom spectra to geometric (derived) orbifold bordism groups (homology theories on finite orbispectra). This isomorphism extends the classical Pontryagin--Thom isomorphism and its known equivariant generalizations.