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Proceedings of the American Mathematical Society

Published by the American Mathematical Society since 1950, Proceedings of the American Mathematical Society is devoted to shorter research articles in all areas of pure and applied mathematics.

ISSN 1088-6826 (online) ISSN 0002-9939 (print)

The 2020 MCQ for Proceedings of the American Mathematical Society is 0.85.

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Homotopy for functors
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by Ming Jung Lee PDF
Proc. Amer. Math. Soc. 36 (1972), 571-577 Request permission

Erratum: Proc. Amer. Math. Soc. 42 (1974), 648-650.

Abstract:

We show that natural transformations play the role of homotopy for (covariant) functors. Homotopic functors are shown to induce identical maps between the homology groups of categories. For a space X, there is an associated category $\Lambda S(X)$. We show that the classifying space of $\Lambda S(X)$ has the same homotopy type as X if X is a CW complex. Moreover, we prove that, for CW complexes X and Y, f and $g:X \to Y$ are homotopic if and only if $\Lambda S(f)$ and $\Lambda S(g)$ are.
References
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Additional Information
  • © Copyright 1972 American Mathematical Society
  • Journal: Proc. Amer. Math. Soc. 36 (1972), 571-577
  • MSC: Primary 55J10
  • DOI: https://doi.org/10.1090/S0002-9939-1972-0334212-5
  • MathSciNet review: 0334212