Math Department Seminar Information
Weekly Seminars
All Seminars are Through Zoom
Mondays
No Seminars
Tuesdays
Topics in Applied Mathematics - Dr. Mark Alber - 9:30 - 10:50 a.m.
Algebraic Geometry - Dr. Jose Gonzalez - 11:00 a.m. - 12:20 p.m.
Lie Theory - Dr. Vyjayanthi Chari - 12:30 - 1:50 p.m.
Lie Groups - Dr. John Baez - 2:00 - 3:20 p.m.
Interdisciplinary Center for Quantitative Modeling in Biology Seminar - Dr. Mark Alber - 2:00 - 3:20 p.m.
Operator Algebras & Related Topics - Dr. Feng Xu - 3:00 - 3:50 p.m.
Wednesdays
Partial Differential Equations & Applied Math - Dr. Weitao Chen - 10:00 - 10:50 a.m.
Combinatorial Number Theory - Dr. Mei-Chu Chang - 11:00 - 11:50 a.m.
Topology - Dr. Stefano Vidussi - 12:00 noon - 12:50 p.m.
Operator Algebras & Related Topics - Dr. Feng Xu - 1:00 - 1:50 p.m.
Modeling in Biology & Physics - Dr. Qixuan Wang - 12:30 - 1:50 p.m.
Thursdays
Topics in Applied Mathematics - Dr. Mark Alber - 9:30 - 10:50 a.m.
Fractal Research Group - Dr. Michel Lapidus - 12:30 - 1:50 p.m.
Lie Theory - Dr. Vyjayanthi Chari - 12:30 - 1:50 p.m.
Lie Groups - Dr. John Baez - 2:00 - 3:20 p.m.
Mathematical Physics & Dynamical Systems - Dr. Michel Lapidus - 3:30 - 4:50 p.m.
Fridays
Differential Geometry - Dr. Po-Ning Chen - 11:00 - 11:50 a.m.
Commutative Algebra - Dr. Eloisa Grifo - 2:00 - 2:50 p.m.
Ergodic Theory & Spectral Theory - Dr. Zhenghe Zhang - 2:00 - 2:50 p.m.
Extended Seminar Schedules
These schedules are provided by their respective coordinators. Not all seminars have extended or current schedules available.
Algebraic Geometry
Spring 2021
https://math.ucr.edu/~joselg/agseminar
| Date | Speaker | Title | Abstract |
| Tuesday, April 6, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
Javier Gonzalez-Anaya UC Riverside |
A review of the theory of varieties. | This is an introductory talk for the graduate students who will attend the seminar this quarter. We will review the theory of varieties: their construction, the Zariski topology and maps between them. We'll provide examples along the way to illustrate these concepts. |
| Tuesday, April 13, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
Rohini Ramadas Brown University |
TBA | TBA |
| Tuesday, April 20, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
Julie Rana Lawrence University |
TBA | TBA |
| Tuesday, April 27, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
Jayan Mukherjee University of Kansas |
Deformations of Galois Canonical Covers and Applications to Moduli of Surfaces with K^2=4p_g-8 | In this talk we will deal with quadruple Galois canonical covers of surfaces of minimal degree. These surfaces satisfy K_X^2 = 4p_g(X)-8. The earlier case of double covers with K_X^2 = 2p_g(X)-4 was studied by Horikawa . This talk will concentrate on the irregular case. The classification of these surfaces by Gallego-Purnaprajna fall into four irreducible families and their work show that these surfaces behave like general surfaces of general type from various geometric perspectives. We show that except for one family, the general deformation of the canonical morphism is a morphism of degree two onto its image whose normalization is a ruled surface of appropriate genus. We further show that the canonical morphism of a general surface for each of these four families cannot be deformed into a finite birational morphism. As a consequence of our results, we show the existence of infinitely many irreducible uniruled components of the Gieseker moduli space containing surfaces with K_X^2 = 4p_g(X)-8, whose general element is a canonical double cover of a non-normal surface whose normalization is an elliptic ruled surface with invariant e = 0. A general surface of each of these moduli components is unobstructed although H^2(T_X) does not vanish. Our results are in sharp contrast with Horikawa's results on deformations of surfaces of general type with K_X^2 = 2p_g - 4. This is joint work with Purnaprajna Bangere, F.J. Gallego and D. Raychaudhury. |
| Tuesday, May 4, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
Camilla Felisetti Università di Trento |
TBA | TBA |
| Tuesday, May 11, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
Christopher Manon University of Kentucky |
TBA | TBA |
| Tuesday, May 18, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
Milena Hering University of Edinburgh |
TBA | TBA |
| Tuesday, May 25, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
TBA TBA |
TBA | TBA |
| Tuesday, June 1, 2021 Start: 11:00 AM Location: Online via Zoom (Please email the organizers if interested.) |
TBA TBA |
TBA | TBA |
Category Theory
https://sites.google.com/ucr.edu/ucrcategoryseminar/home
Fall 2020 UC Riverside seminar for Category Theory and Applications
Organizers Joe Moeller, Jade Master, Christian Williams Advisor John Baez
Schedule (not determined, still flexible)
10/12 JC Symmetric monoidal closed categories
10/19 Jade The algebraic path problem
10/26 Sarah Equivariant homotopy theory
11/02 David Double categories and open systems
11/09 John Categorifying the natural numbers
11/16 Chris Logic of cartesian closed categories
11/23 Christian co/Monads
11/30 Joe Schur functors
12/07 Todd Topos Theory
Commutative Algebra
https://eloisagrifo.github.io/UCRseminar.html
Spring 2021 Schedule
April 9, 2021
Nora E. Youngs (Colby College)
Title: Using algebraic geometry to understand the neural code
Abstract: One major problem in neuroscience is to understand how the brain uses neural activity to form representations of the external world. It is known that combinatorial information in the firing patterns of neurons often reflects important features of the stimuli that generated them. How can we efficiently extract such information? This talk will introduce a method from algebraic geometry that we can use to encode and extract combinatorial structure from neural codes. We will discuss how this structure can be used to infer features of the underlying stimulus space, and some of the issues that arise under this approach.
April 16, 2021
Francesca Gandini (Kalamazoo College)
Title TBA
Abstract: TBA
April 23, 2021
Lance Miller (Arkansas)
Title TBA
Abstract: TBA
May 14, 2021
José González (UCR)
Title TBA
Abstract: TBA
May 21, 2021
Haydee Lindo (Harvey Mudd College)
Title TBA
Abstract: TBA
May 28, 2021
Patricio Gallardo (UCR)
Title TBA
Abstract: TBA
Differential Geometry
The Schedule for the Spring of 2021, Fridays 11:00 - 11:50 a.m.
Email Dr. Brian Collier for the Zoom link
https://sites.google.com/view/brian-collier/ucr-differential-geometry-seminar
April 2, 2021 : Xian Dai (Heidelberg University)
Title: Correlation of Convex Projective Structures and Its Generalization
Abstract: In this talk, we will show an asymptotic formula for the number of free homotopy classes with roughly the same renormalized Hilbert length for two distinct convex real projective structures. We will also generalize the formula to Hitchin representations for general lengths given by linear functionals. The study of correlations between hyperbolic structures has first been started by Richard Schwartz and Richard Sharp using thermodynamic formalism. We will answer a question of them in the negative about whether the correlation number is bounded away from zero in Teichmüller space. This is joint work with Giuseppe Martone.
April 9, 2021 : Elahe Khalili Samani (Syracuse University)
Title: Positively curved manifolds with discrete symmetry
Abstract: Riemannian manifolds with positive sectional curvature are of special interest in Riemannian geometry. While it is difficult to classify all such manifolds, there are many results under additional symmetry assumptions. In this talk, we review some of the results in the presence of torus symmetry, and then discuss generalizations to the case of discrete symmetry. This is based on joint work with Lee Kennard and Catherine Searle.
April 16, 2021 : Ivo Slegers (Universität Bonn)
Title: The energy functional of a Hitchin representation
Abstract: In this talk we will discuss the energy functionals on Teichmüller space that are associated to Hitchin representations. We will show that these functionals are strictly plurisubharmonic functions on Teichmüller space. In the second half of this talk we consider the question whether a Hitchin representation is uniquely determined by its energy functional. We answer a similar question in a simpler setting (non-positively curved metrics on surfaces) and discuss work in progress on how these results can be expanded to include Hitchin representations.
April 23, 2021 : Jeremy Toulisse (University of Nice)
Title: Plateau problem in psuedo-hyperbolic space
Abstract: The pseudo-hyperbolic space H^{2,n} is the pseudo-Riemannian analogue of the classical hyperbolic space. In this talk, I will explain how to solve an asymptotic Plateau problem in this space: given a topological circle in the boundary at infinity of H^{2,n}, we construct a unique complete maximal surface bounded by this circle. This construction relies on Gromov’s theory of pseudo-holomorphic curves. This is a joint work with François Labourie and Mike Wolf.
April 30, 2021: Markus Röser (Universität Hamburg)
Title: TBA
Abstract:
May 7, 2021: Hadrian Quan (University of Illinois)
Title: TBA
Abstract: TBA
May 14, 2021: Jonas Beyrer (IHES)
Title:
Abstract:
May 21, 2021: Laura Fredrickson (University of Oregon)
Title: TBA
Abstract:
May 28, 2021: Claudio Meneses (Christian-Albrechts-Universität Kiel)
Title: TBA
Abstract:
June 4, 2021: Chaya Norton (University of Michigan)
Title: TBA
Abstract:
Fractal Research Group
Weekly Seminars on Thursdays in Surge 268:
- FRG (Fractal Research Group) Seminar: 11:00 am -12:20 pm.
- MPDS (Mathematical Physics & Dynamical Systems) Seminar: 3:30-4:50 pm.
More detailed information (such as speakers, titles, abstracts & workshops) are available in the google calendar below.
Ergodic Theory & Spectral Theory
Graduate Student Seminar
Fall 2020 TBP
Lie Theory
https://sites.google.com/view/petersamuelson/lie-theory-seminar
Lie Theory
This is the (minimal) website for the Lie Theory Seminar at UCR for the Winter 2021 quarter, which is organized by Vyjayanthi Chari.(The W2020 and F2020 schedules are below for posterity.)
The graduate students organize a Lie Theory Seminar for graduate students, as an extension of the Lie Theory Seminar to give talks on different areas in Representation Theory. The website is here.
March 30: Eugene Gorsky, Cyclotomic expansions for gl(N) knot invariants via interpolation Macdonald polynomials
April 6: TBA
April 13: TBA
April 20: Oded Yacobi
April 27: Brian Collier, Positivity and nilpotents with applications to character varieties
May 4: TBA
May 11: TBA
May 18: TBA
May 25: TBA
June 1: TBA
Mathematical Physics & Dynamical Systems
Weekly Seminars on Thursdays in Surge 268:
- FRG (Fractal Research Group) Seminar: 11:00 am -12:20 pm.
- MPDS (Mathematical Physics & Dynamical Systems) Seminar: 3:30-4:50 pm.
More detailed information (such as speakers, titles, abstracts & workshops) are available in the google calendar below.
Partial Differential Equations & Applied Math
Spring 2021 Schedule
https://sites.google.com/ucr.edu/ucriverside-math-ampde-seminar/
Apr 7 10:00 (Wed) Xingjie Li (University of North Carolina, at Charlotte) (QW,HC)
Apr 14 10:00 (Wed) Franziska Weber (Carnegie Mellon University)
Apr 21 10:00 (Wed) Denis Tsygankov (Georgia Tech) (QW)
Apr 21 12:00 (Wed) Rishi Sonthalia (University of Michigan) (joint with Topology seminar)
Apr 28 10:00 (Wed) Yang Yang (Michigan Technological University) (HC)
May 5 10:00 (Wed) Kevin Sanft (University of North Carolina Asheville) (QW)
May 12 10:00 (Wed) Yeonjong Shin (Brown University) (HC)
May 19 10:00 (Wed) Zhongqiang Zhang (Worcester Polytechnic Institute) (HC)
May 26 10:00 (Wed) Wei Guo (Texas Tech University) (WC)
June 2 10:00 (Wed) Steven Woodhouse (University of Pennsylvania) (QW)
Topology
https://sites.google.com/view/ucrtopologyseminar/home
Spring 2021 Schedule
March 31, 12:00-1:30, Zoom
İnanç Baykur (University of Massachusetts) 🔗
Title: Lefschetz fibrations, symplectic geography and exotic 4-manifolds.
Abstract: We will talk about our recent construction of symplectic Lefschetz fibrations with arbitrary signatures and spin type, along with novel applications to the geography of symplectic 4-manifolds, constructions of new exotic 4-manifolds, and speculations on exotically knotted surfaces in the 4-sphere. This is joint work with N. Hamada.
April 14, 12:00-1:30, Zoom
Stefano Vidussi
Title: Algebraic fibrations of surface-by-surface groups.
Abstract: An algebraic fibration of a group G is an epimorphism to the integers with a finitely generated kernel. This notion has been studied at least since the '60s, and has recently attracted renewed attention. Among other things, we will study it in the geometric context of fundamental groups of surface bundles over a surface, where it has some interesting relations with some classical problems about the mapping class group. This is based on joint work with S. Friedl, and with R. Kropholler and G. Walsh.
April 21, 12:00-1:30, Zoom
Rishi Sonthalia (University of Michigan) 🔗
Title: Learning Optimal Metrics.
Abstract: Given a set of dissimilarity measures amongst data points, many machine learning problems are considerably ``easier'' if these dissimilarity measures adhere to a metric. Furthermore, learning the metric that is most ``consistent'' with the input dissimilarities or the metric that best captures the relevant geometric features of the data (e.g., the correlation structure in the data) is a key step in efficient, approximation algorithms for classification, clustering, regression, and feature selection. In practice, these metric learning problems are formulated as convex optimization problems subject to metric constraints, such as the triangle inequality, on all the output variables. Because of the large number of constraints, researchers have been forced to restrict either the kinds of metrics learned or the size of the problem that can be solved. In many cases, researchers have restricted themselves to learning (weighted) Euclidean or Mahalanobis metrics. This approach is, however, far from ideal as the inherent geometry of many data sets necessitates different types of metrics. Therefore, we need to develop optimization techniques that can optimize over the space of all metrics on a data set. In this talk, I will present many different aspects of the metric learning problem; the sparse version, the general convex version, and how such ideas can be used for dimensionality reduction in the presence of missing data.
April 28, 12:00-1:30, Zoom
Dawid Kielak (Oxford) 🔗
Title: Recognizing surface groups .
Abstract: I will address two problems about recognizing surface groups. The first one is the classical problem of classifying Poincaré duality groups in dimension two. I will present a new approach to this, joint with Peter Kropholler. The second problem is about recognizing surface groups amongst one-relator groups. Here I will present a new partial result, joint with Giles Gardam and Alan Logan. .
May 5, 12:00-1:30, Zoom
Efstratia Kalfagianni (Michigan State University) 🔗
Title: TBA.
Abstract: TBA.
May 12, 12:00-1:30, Zoom
Claudio Llosa Isenrich (Karlsruher Institut für Technologie) 🔗
Title: TBA.
Abstract: TBA.
May 19, 12:00-1:30, Zoom
Bena Tshishiku (Brown University) 🔗
Title: TBA.
Abstract: TBA.
May 26, 12:00-1:30, Zoom
TBA 🔗
Title: TBA.
Abstract: TBA.
June 2, 12:00-1:30, Zoom
TBA 🔗
Title: TBA.
Abstract: TBA.