Date/Time
Date(s) - 19/09/2025
3:30 pm - 4:30 pm

Location: Hamilton Hall, Room 305

Facutly Threads: 

Speaker 1:  Patrick Speissegger
Title: A Hardy field containing the germs at infinity of the Gamma and Zeta functions
Abstract:  Together with my students Ilgwon Seo and Carlos Cordoba, we are trying to Show that certain Hardy fields can be expanded by the germs at infinity of multisummable functions.  To explain how, I will use the example of the Hardy field generated by the germ of the Zeta function.

Speaker 2: Gail Wolkowicz
Title: An Augmented Phase Plane Approach to Analyze Discrete Planar Models
Abstract: It is shown why phase-plane analysis of planar maps has not been as useful as it has been for planar systems of ordinary differential equations. To rectify this issue the next-iterate operator associated with the nullclines and their associated root-curves is introduced. This provides an elementary approach that can be applied to analyze discrete planar models.

A stand alone GUI, to generate phase planes of discrete planar systems based on this approach is available at: https://github.com/sabrinaheike/AugmentedPhasePortrait/tree/main and will be demonstrated.
The method is described in detail in:
Sabrina H. Streipert and Gail S. K. Wolkowicz, (2023) “An augmented phase plane approach for discrete planar maps: Introducing next-iterate operators ,”Mathematical Biosciences, 355, 108924, 19 https://doi.org/10.1016/j.mbs.2022.108924

Speaker 3: Bartek Protas
Title: On the Vagaries of the Taylor-Green Vortex
Abstract: We will consider a classical problem in mathematical fluid mechanics which is simple to state, yet admits a rather nuanced solution. It has to do with instabilities of the Taylor-Green vortex in Euler flows, which cannot be fully understood without explicitly accounting for the infinite-dimensional nature of the problem. We will also show how insights about the mathematical analysis of underlying PDE can be obtained from carefully designed and executed numerical computations.

Coffee will be served in the same room, HH 305 at 3:00pm. All are welcome.