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Upcoming Events

Branwen Purdy at her stall during OMSI meet-a-scientist day.

Branwen Purdy prepares hands-on activities for kids at the OMSI Meet-A-Scientist Day in Portland, to share hands-on learning experiences about her research in topological data analysis.

Join us for these events hosted by the Department of Mathematics, including colloquia, seminars, graduate student defenses and outreach, or of interest to Mathematicians hosted by other groups on campus.

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Valuation Rings over Function Field

STAG 112
Graduate Student Seminar

Speaker: Peyton Pfeiffer

In this talk, we will discuss algebraic concepts used to study function fields of one variable such as valuation rings. We will see that the valuation rings of a function field correspond to the places and discrete valuation functions of a function field. These aspects of function fields offer a more algebraic approach to important ideas in algebraic geometry such as the Riemann-Roch theorem. Read more.


Symmetry, Classification, and Positive Curvature

STAG 163
REU Colloquium

Speaker: Austin Bosgraaf

Classification problems are ubiquitous in mathematics; and in study of Riemannian manifolds with positive sectional curvature, classification is a central theme. In 2003, Wilking introduced a set of topological tools to the study of positive sectional curvature which led to new classification results in the presence of torus symmetry. This talk will overview some classical results in positive sectional curvature, before introducing Wilking's tools and discussing their applications. We will then see recent results in positive sectional curvature due to Kennard, Khalili Samani, and Searle in the case of discrete symmetries, and I will finish by presenting some of my own results. Read more.


q-series Identities Connected to Ideals in Quadratic Fields

STAG 163
REU Colloquium

Speaker: Lucas Perryman-Deskins

A certain $q$-hypergeometric series $\sigma$ was shown by Andrews, Dyson, and Hickerson to have an interpretation in terms of counting ideals in $\mathbb{Z}(\sqrt{6})$. This interpretation was used to demonstrate unique combinatorial and analytic characteristics, along with some interesting $q$-series identities. Some of these identities reflect a correspondence, predicted by class field theory, between characters on the ideals of each quadratic subfield of a biquadratic field. Cohen described that there are many quadratic fields where similar identities are theoretically discoverable, but few have been actually explored. Cohen also constructed from $\sigma$ a related Maass form, with later work generalizing this construction to a class of functions which are mock Maass theta functions, and in special cases Maass forms. In this talk, I will discuss the some background in each of these areas, and the history of research on this problem, as well as my current approach working towards… Read more.