Spring 2026

 

19 and 26 March

John McSorley

Special and super graph special subgraphs of a graph 

Spring 2026

5 March

Philip Feinsilver

Leverrier-Faddeev and a basic recursion

Video

Abstract: The method of synthetic substitution in elementary algebra is the basis of an elegant method presented by the astronomer Leverrier to find the characteristic polynomial of a matrix without evaluating determinants.

Spring 2026

26 Feb 2026

Jakson Lewis

Observations on Representations of Lie Algebras via Harmonic Oscillators

Abstract: We present the method of representing Lie Algebras with the use of the algebra of Harmonic Oscillators, and with that present an interesting challenge and interesting results discovered from such investigations. 

Spring 2026

From arstexnica

12 and 19 February

Mohammad Sayeh

Nobel AI

Mike Sullivan shares with you two books that he read on the history of AI/machine learning:

• What is ChatGPT Doing …and Why Does it Work (by Stephen Wolfram)
• Why Machines Learn (by Anil Ananthaswamy)

(From Mohammad: see also Hopfield's early work:  1982Hopfield ,  1984Hopfield, 1985Hopfield, 1986Hopfield ).

Spring 2026

5 February

Ronald White

An introduction to non-associative algebra

Abstract:   In this talk, we begin by introducing some of the more common non-associative operations and showing how we use them in everyday contexts. We then move into algebraic structures, starting with a magma, a set that is simply closed under a single binary operation. From there, we gradually impose additional structure until we arrive at loops, which can be thought of as groups that are not necessarily associative. This is where we will spend the remainder of our time, exploring what these structures contribute to our understanding of groups and what questions we can study about them in their own right.

SPRING 2026

22 and 29 January

Jerzy Kocik

A group, an application, a puzzle, and an analog toy

(moduli space of Apollonian disk packing via the bimodular group)  

Autumn 2025

René Magritte, "This is Not a Pipe."

4 December 

Leonard Fowler

Math and not-Math

Autumn 2025

20 November 

Mohammad Sayeh

Future before Now:  anticipatory (proteretic) structure

Autumn 2025

30 October, 6 and 13 November

Jackson Lewis

Hyperbolic Angular Momentum from the ground up

Abstract:  We present the construction of “hyperbolic angular momentum” as given by Schwinger (1951), starting with the basic one-dimensional oscillator of classical mechanics. Then we introduce harmonic oscillators in quantum mechanics, angular momentum in classical and quantum mechanics, and the Jordan-Schwinger Map. Some applications will be discussed, possibly including constructions of spin networks and discrete spacetime operators in loop quantum gravity.  

From "Math for Poets..."

16, 23  Oct 2025

Mathew Gluck

The Method of Moving Spheres

Abstract. The method of moving spheres is a powerful and versatile method for analyzing partial differential equations with conformal symmetry. At the core of this method is the amazing fact that one can classify all suitably nice functions f  defined on Euclidean space for which both of the following properties hold:

1.  For every point x there is a sphere centered at x about which f  has inversion symmetry, and

2.  for every direction e, there is a hyperplane with normal direction e about which f  has reflection symmetry.

I will give some examples of functions for which both properties hold, and I will discuss the historical development of the classification of all such functions. Finally, I will overview the method of moving spheres and provide some applications of the method in the analysis of conformally covariant partial differential equations.

Autumn 2025

3 and 10  October

Viska Arbogast

Numbers as Equations

Autumn 2025

 

From Wikipedia

11, 18, 25  Sep 2025

Jerzy Kocik

Coxeter groups, and an unconventional view on the unimodular group (with pictures)

Part 1:  Coxeter groups (the idea)

Part 2:  Modular group as a Coxeter group

Part 3:  "Supermodular" group and an unexpected application 

For part 1, you may consult a nicely written text by J. Baez:  Coxeter and Dynkin diagrams.