Birkhoff's variety theorem for relative algebraic theories

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Kawase, Yuto
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916693324857344
author Kawase, Yuto
author_facet Kawase, Yuto
contents An algebraic theory, sometimes called an equational theory, is a theory defined by finitary operations and equations, such as the theories of groups and of rings. It is well known that algebraic theories are equivalent to finitary monads on $\mathbf{Set}$. In this paper, we generalize this phenomenon to locally finitely presentable categories using partial Horn logic. For each locally finitely presentable category $\mathscr{A}$, we define an "algebraic concept" relative to $\mathscr{A}$, which will be called an $\mathscr{A}$-relative algebraic theory, and show that $\mathscr{A}$-relative algebraic theories are equivalent to finitary monads on $\mathscr{A}$. In establishing such equivalence, a generalized Birkhoff's variety theorem plays an important role.
format Preprint
id arxiv_https___arxiv_org_abs_2304_04382
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Birkhoff's variety theorem for relative algebraic theories
Kawase, Yuto
Category Theory
18C10, 18C15, 18C35, 18E45
An algebraic theory, sometimes called an equational theory, is a theory defined by finitary operations and equations, such as the theories of groups and of rings. It is well known that algebraic theories are equivalent to finitary monads on $\mathbf{Set}$. In this paper, we generalize this phenomenon to locally finitely presentable categories using partial Horn logic. For each locally finitely presentable category $\mathscr{A}$, we define an "algebraic concept" relative to $\mathscr{A}$, which will be called an $\mathscr{A}$-relative algebraic theory, and show that $\mathscr{A}$-relative algebraic theories are equivalent to finitary monads on $\mathscr{A}$. In establishing such equivalence, a generalized Birkhoff's variety theorem plays an important role.
title Birkhoff's variety theorem for relative algebraic theories
topic Category Theory
18C10, 18C15, 18C35, 18E45
url https://arxiv.org/abs/2304.04382