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arXiv · 2607.09667

Undecidability of the quasi-isomorphism problem for semi-free dg algebras via the cobar construction

Manuel Rivera
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Abstract

We explain how the undecidability of the quasi-isomorphism and derived Morita equivalence problems for semi-free finitely presented dg associative algebras follows as an immediate consequence of an extension of Adams' cobar theorem to non-simply connected spaces and the triviality problem for finitely presented groups.

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Manuel Rivera. 2026-05-23. Undecidability of the quasi-isomorphism problem for semi-free dg algebras via the cobar construction. https://arxiv.org/abs/2607.09667

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