# Past Events

## Events Search and Views Navigation

## November 2021

### Applied Math Seminar — Christopher Miles (UC Irvine)

Title: Collective motion in the mitotic spindle Abstract: Math models of interacting individuals moving as a collective have been profoundly successful in describing physical and social phenomena ranging from swarming insects to human crowds. Especially in molecular biology, recent advances in machine-learning-based automated tracking have led to droves of new data of collective motion. I’ll discuss two related projects, both studying chromosomes (DNA) moving during mitosis (cell division). The first project will hopefully convince you that modeling this system as a collective is…

Find out more »### On sparse representation of vectors in lattices and semigroups (Iskander Aliev, Cardiff University)

We will discuss the sparsity of the solutions to systems of linear Diophantine equations with and without non-negativity constraints. The sparsity of a solution vector is the number of its nonzero entries, which is referred to as the 0-norm of the vector. Our main results are new improved bounds on the minimal 0-norm of solutions to systems Ax=b, where A is an integer matrix, b is an integer vector and x is either a general integer vector (lattice case) or…

Find out more »### Collective Behavior in Locust Swarms from Data to Differential Equations (Prof. Jasper Weinburd)

Title: Collective Behavior in Locust Swarms from Data to Differential Equations Prof. Jasper Weinburd Department of Mathematics Harvey Mudd College Abstract: Locusts are devastating pests that infest and destroy crops. Locusts forage and migrate in large swarms which exhibit distinctive shapes that improve efficiency on the group level, a phenomenon known as collective behavior. One of the difficulties in understanding and preventing these collective behaviors has been a lack of biological data for individual interactions between locusts. In…

Find out more »### Thanksgiving Week

No applied math talk

Find out more »### Applied Math Seminar – Joan Ponce (UCLA)

Title: TBA Abstract: TBA

Find out more »### Odd subgraphs are odd (Asaf Ferber, UC Irvine)

In this talk we discuss some problems related to finding large induced subgraphs of a given graph G which satisfy some degree-constraints (for example, all degrees are odd, or all degrees are j mod k, etc). We survey some classical results, present some interesting and challenging problems, and sketch solutions to some of them. This is based on joint works with Michael Krivelevich, and with Liam Hardiman and Michael Krivelevich.

Find out more »## December 2021

### A tribute to Professor Ellis Cumberbatch (1934-2021)

Title: A tribute to Professor Ellis Cumberbatch (1934-2021) Abstract: The math colloquium on December 1st will be devoted to remembrances of our beloved CGU colleague Professor Ellis Cumberbatch, a pillar of the Claremont mathematics community, who passed away in September. Three brief talks by his friends and collaborators, Professor John Ockendon (University of Oxford), Dr. Henok Abebe (Sandia National Labs), and Professor Asuman Aksoy (Claremont McKenna College) will be followed by informal reminiscences by any of the attendees who wish…

Find out more »### Difference sets in higher dimensions (David Conlon, Cal Tech)

Let d >= 2 be a natural number. We determine the minimum possible size of the difference set A-A in terms of |A| for any sufficiently large finite subset A of R^d that is not contained in a translate of a hyperplane. By a construction of Stanchescu, this is best possible and thus resolves an old question first raised by Uhrin. Joint work with Jeck Lim.

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