Algebra Seminar talk
2018-04-13 (10:30!)
Erhard Aichinger (JKU Linz)
Finitely generated equational classes
Abstract:
Classes of algebraic structures that are defined by equational laws are called *varieties* or *equational classes*. A variety is *finitely generated*
if it is defined by the laws that hold in some fixed finite algebra.
We show that every subvariety of a finitely generated congruence permutable
variety is finitely generated, thereby giving a partial solution
to Problem 10.1 from "Sixty-four problems in universal algebra"
by McKenzie et al. Our result applies in particular to
all varieties of groups, loops, quasigroups, and their expansions
(e.g., modules, rings, ...).
In the proof, we represent equational theories by certain sets of finitary
functions called *clonoids*.
This is joint work with Peter Mayr (U Colorado Boulder) and supported by
the Austrian Science Fund FWF: P29931.