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arXiv · 2307.15937

Universal monoid actions: the power of freedom

Wieslaw Kubiś
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Abstract

Motivated by a recent work of Balcerzak and Kania [Proc. Amer. Math. Soc. 151 (2023) 3737--3742], we show that every countable monoid has a universal action on the free object over a countable infinite set. This is a general result concerning concrete categories with a left adjoint (free) functor. On the way, we introduce an abstract concept of ``being generated by a set". At the same time we obtain a simpler proof of the result of Darji and Matheron concerning a surjectively universal operator on the classical Banach space $\ell_1$ of summable sequences.

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Wieslaw Kubiś. 2023-07-29. Universal monoid actions: the power of freedom. https://arxiv.org/abs/2307.15937

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