Time: Monday, October 23. (SC 1312, 4:10 p.m.)
Speaker: Andrew Moorhead
Title: Abelianness in Universal Algebra I

Time: Monday, October 30. (SC 1312, 4:10 p.m.)
Speaker: Andrew Moorhead
Title: Abelianness in Universal Algebra II

Time: Monday, November 6. (SC 1312, 4:10 p.m.)
Speaker: Andrew Moorhead
Title: Abelianness in Universal Algebra III

Time: Monday, November 13. (SC 1312, 4:10 p.m.)
Speaker: Andrew Moorhead
Title: Abelianness in Universal Algebra IV

Time: Tuesday, November 28. (SC TBA, 4:10 p.m.)
Speaker: Stephen G. Simpson
Title: Linear Lattices
Abstract: Let Eq(X) denote the lattice of all equivalence relations on a fixed set X. Let o denote relational composition. Two equivalence relations e1 and e2 on X are said to commute if  e1 o e2 = e2 o e1. By a linear lattice we mean a sublattice of Eq(X) consisting of commuting equivalence relations. A standard example of a linear lattice is a projective geometry, i.e., the lattice of finite dimensional subspaces of a fixed vector space X.  Linear lattices have been studied for well over a century. Some of the names here are Dedekind, Birkhoff, Malcev, Jónsson, Rota, Haiman, and Yan. We discuss some of this history, and we present a new result and a current research problem.

Time: Monday, December 4. (SC 1312, 4:10 p.m.)
Speaker: Stephen G. Simpson
Title: Linear Lattices II
Abstract: Let Eq(X) denote the lattice of all equivalence relations on a fixed set X. Let o denote relational composition. Two equivalence relations e1 and e2 on X are said to commute if  e1 o e2 = e2 o e1. By a linear lattice we mean a sublattice of Eq(X) consisting of commuting equivalence relations. A standard example of a linear lattice is a projective geometry, i.e., the lattice of finite dimensional subspaces of a fixed vector space X.  Linear lattices have been studied for well over a century. Some of the names here are Dedekind, Birkhoff, Malcev, Jónsson, Rota, Haiman, and Yan. We discuss some of this history, and we present a new result and a current research problem.