Colloquia/Spring2023: Difference between revisions

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<b>UW Madison mathematics Colloquium is on Fridays at 4:00 pm. </b>
<!--- in Van Vleck B239, '''unless otherwise indicated'''. --->
== February 3, 2023, Friday at 4pm [https://sites.google.com/a/uwlax.edu/tdas/ Facundo Mémoli] (Ohio State University) ==
(host: Lyu)
The Gromov-Hausdorff distance between spheres.
The Gromov-Hausdorff distance is a fundamental tool in Riemanian geometry (through the topology it generates) and is also utilized in applied geometry and topological data analysis as a metric for expressing the stability of methods which process geometric data (e.g. hierarchical clustering and persistent homology barcodes via the Vietoris-Rips filtration). In fact, distances such as the Gromov-Hausdorff distance or its Optimal Transport variants (i.e. the so-called Gromov-Wasserstein distances) are nowadays often invoked in applications related to data classification.
Whereas it is often easy to estimate the value of the Gromov-Hausdorff distance between two given metric spaces, its ''precise'' value is rarely easy to determine. Some of the best estimates follow from considerations related to both the stability of persistent homology and to Gromov's filling radius. However, these turn out to be non-sharp.
In this talk, I will describe these estimates and also results which permit calculating the precise value of the Gromov-Hausdorff between pairs of spheres (endowed with their usual geodesic distance). These results involve lower bounds which arise from a certain version of the Borsuk-Ulam theorem that is applicable to discontinuous maps, and also matching upper bounds which are induced from specialized constructions of (a posteriori optimal) ``correspondences" between spheres.
== February 24, 2023, Cancelled/available ==
== March 3, 2023, Friday at 4pm [https://faculty.washington.edu/steinerb/ Stefan Steinerberger]  (University of Washington) ==
(hosts: Shaoming Guo, Andreas Seeger)
== March 8, 2023, Wednesday at 4pm [https://math.yale.edu/people/yair-minsky Yair Minsky]  (Yale University) ==
Distinguished lectures
(host: Kent)
== March 10, 2023, Friday at 4pm [https://math.yale.edu/people/yair-minsky Yair Minsky]  (Yale University) ==
Distinguished lectures
(host: Kent)
== March 24, 2023 , Friday at 4pm  [https://www.carolynrabbott.com/ Carolyn Abbott] (Brandeis University) ==
(host: Dymarz, Uyanik, WIMAW)
== March 31, 2023 , Friday at 4pm [http://www.math.toronto.edu/balint/ Bálint Virág] (University of Toronto) ==
(host: Benedek Valko)
== April 7, 2023, Friday at 4pm  [https://www.mi.fu-berlin.de/math/groups/fluid-dyn/members/rupert_klein.html Rupert Klein] (FU Berlin) ==
Wasow lecture
(hosts: Smith, Stechmann)
== April 21, 2023, Friday at 4pm [https://sternber.pages.iu.edu/ Peter Sternberg]  (Indiana University) ==
(hosts: Feldman, Tran)
== Past Colloquia ==
[[Colloquia/Fall2022|Fall 2022]]
[[Colloquia/Spring2022|Spring 2022]]
[[Colloquia/Fall2021|Fall 2021]]
[[Colloquia/Spring2021|Spring 2021]]
[[Colloquia/Fall2020|Fall 2020]]
[[Colloquia/Spring2020|Spring 2020]]
[[Colloquia/Fall2019|Fall 2019]]
[[Colloquia/Spring2019|Spring 2019]]
[[Colloquia/Fall2018|Fall 2018]]
[[Colloquia/Spring2018|Spring 2018]]
[[Colloquia/Fall2017|Fall 2017]]
[[Colloquia/Spring2017|Spring 2017]]
[[Archived Fall 2016 Colloquia|Fall 2016]]
[[Colloquia/Spring2016|Spring 2016]]
[[Colloquia/Fall2015|Fall 2015]]
[[Colloquia/Spring2014|Spring 2015]]
[[Colloquia/Fall2014|Fall 2014]]
[[Colloquia/Spring2014|Spring 2014]]
[[Colloquia/Fall2013|Fall 2013]]
[[Colloquia 2012-2013|Spring 2013]]
[[Colloquia 2012-2013#Fall 2012|Fall 2012]]
[[WIMAW]]

Revision as of 17:49, 17 February 2023