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CELLULAR CATEGORIES AND STABLE INDEPENDENCE

Published online by Cambridge University Press:  18 May 2022

MICHAEL LIEBERMAN*
Affiliation:
INSTITUTE OF MATHEMATICS, FACULTY OF MECHANICAL ENGINEERING BRNO UNIVERSITY OF TECHNOLOGY BRNO, CZECH REPUBLIC URL: https://math.fme.vutbr.cz/Home/lieberman
JIŘÍ ROSICKÝ
Affiliation:
DEPARTMENT OF MATHEMATICS AND STATISTICS FACULTY OF SCIENCE MASARYK UNIVERSITY BRNO, CZECH REPUBLIC E-mail: rosicky@math.muni.cz URL: http://www.math.muni.cz/~rosicky/

Abstract

We exhibit a bridge between the theory of cellular categories, used in algebraic topology and homological algebra, and the model-theoretic notion of stable independence. Roughly speaking, we show that the combinatorial cellular categories (those where, in a precise sense, the cellular morphisms are generated by a set) are exactly those that give rise to stable independence notions. We give two applications: on the one hand, we show that the abstract elementary classes of roots of Ext studied by Baldwin–Eklof–Trlifaj are stable and tame. On the other hand, we give a simpler proof (in a special case) that combinatorial categories are closed under 2-limits, a theorem of Makkai and Rosický.

Type
Article
Copyright
© The Author(s), 2022. Published by Cambridge University Press on behalf of The Association for Symbolic Logic

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