Presentations and Workshops
- February 9, 2026 (upcoming, virtual)
Using the First Coefficient of the Laurent Expansion of the Hilbert Series to Distinguish Between Singularities of Symplectic Quotients
Joint work with Hans-Christian Herbig, Daniel Herden, and Harper Kolehmainen
Augustana University Senior Math Colloquium,
Sioux Falls, South Dakota.
- January 5, 2026
Equivariant and universal Euler characteristics for definable groupoids
Joint work with Carla Farsi and Emily Proctor
Joint Mathematics Meetings, Special Session on Singular Riemannian Foliations, Lie Groupoids, and Spectra of Singular Spaces, Washington, D.C.
- November 15, 2025
The Burnside group/ring of a definable groupoid
Joint work with Carla Farsi and Emily Proctor
Groupoidfest 2025, New Mexico State University, Las Cruces, New Mexico
- March 8, 2025
Distinguishing between linear symplectic quotients using the Laurent coefficients of the Hilbert series
Joint work with Hans-Christian Herbig, Daniel Herden, and Harper Kolehmainen
Gone Fishing 2025, Washington University in St. Louis,
St. Louis, Missouri.
- February 21, 2025
Distinguishing between singular symplectic quotients using invariant theory
Joint work with Hans-Christian Herbig and Gerald Schwarz
Differential Geometry, Topology, and Special Structures Seminar, CUNY,
New York, New York.
- December 4, 2024
Moving Numbers from Boxes to Other Boxes: Using the First Coefficient of the Laurent Expansion of the Hilbert Series to Distinguish Between Singularities of Symplectic Quotients
Joint work with Hans-Christian Herbig, Daniel Herden, and Harper Kolehmainen
Skidmore College Department of Mathematics and Statistics Colloquium Series
- October 19, 2024
Distinguishing between symplectic quotients of S1– and SU(2)-representations using Laurent coefficients of the Hilbert series
Joint work with Hans-Christian Herbig, Daniel Herden, and Harper Kolehmainen
2024 Fall Eastern Sectional Meeting of the AMS, University of Albany,
Albany, New York.
- October 6, 2024 (virtual due to cancellation of the AMS Meeting)
Isomorphisms of linear symplectic torus quotients
Joint work with Hans-Christian Herbig and Gerald Schwarz
Special Session on Poisson geometry, Diffeology and Singular Spaces, 2024 Fall Southeastern Sectional Meeting of the AMS, Georgia Southern University,
Savannah, Georgia.
- September 25, 2024
Some Fun With Roots of Unity
Geneseo Mathematics Colloquium, SUNY Geneseo,
Geneseo, New York.
- April 14, 2024
Classifying linear symplectic torus quotients
Joint work with Hans-Christian Herbig and Gerald Schwarz
Gone Fishing 2024, Northwestern University,
Evanston, Illinois.
- November 12, 2023
A universal Euler characteristic for orbit space definable groupoids and orbifold Euler characteristics of Riemannian Lie groupoids
Joint work with Carla Farsi and Emily Proctor
GroupoidFest 2023, Arizona State University,
Tempe, Arizona.
- November 12, 2022
Orbifold Euler characteristics of proper Lie and definable groupoids
Joint work with Carla Farsi
GroupoidFest 2022, University of Colorado at Boulder,
Boulder, Colorado.
- November 11, 2022
Rational singularities of the zero fiber of the moment map
Joint work with Hans-Christian Herbig and Gerald Schwarz
University of Colorado at Boulder Mathematics Seminar,
Boulder, Colorado.
- November 11, 2021 (virtual)
Rational singularities of the zero fiber of the moment map, symplectic quotients, and applications to representation and character varieties of surface group
Joint work with Hans-Christian Herbig and Gerald Schwarz
Baylor University Mathematics Colloquium,
Baylor University, Texas.
- November 3, 2020 (virtual)
Computing the Hilbert series of the real regular functions on a symplectic quotient by the 2-torus
Joint work with Hans-Christian Herbig and Daniel Herden
Seminário Simplético do Rio (Joint Symplectic Seminar), IMPA, PUC-RJ, UFF and UFRJ,
Rio de Janeiro, Brazil.
- January 13-22, 2020
Bernoulli Brainstorm: Real and complex geometry of Hamiltonian reductions
With Hans-Christian Herbig, Simon Lyakhovich, and Gerald Schwarz
Bernoulli Center (CIB), Ecole polytechnique fédérale de Lausanne (EPFL),
Lausanne, Switzerland.
- January 6-10, 2020
Research in Pairs: Real and complex geometry of Hamiltonian reductions
With Hans-Christian Herbig, Simon Lyakhovich, and Gerald Schwarz
Centre International de Rencontres Mathématiques (CIRM),
Marseille, France.
- December 18, 2019
Singularities of symplectic quotients and computational invariant theory
Joint work with Hans-Christian Herbig, Daniel Herden, and Gerald Schwarz
Workshop of Algebra and Geometry, Sultan Qaboos University,
Muscat, Oman.
- September 24, 2019
Can one approximately hear orbifold singularities?
Joint work with Carla Farsi and Emily Proctor
Middlebury College Department of Mathematics,
Middlebury, Vermont.
- September 28, 2018
Distinguishing between symplectic quotients by SU2 using invariant theory
Joint work with Hans-Christian Herbig, and Daniel Herden
University of Mississippi Department of Mathematics Graduate Student Seminar,
Oxford, Mississippi.
- August 4, 2018
The Hilbert series and Laurent coefficients of SL2(C)-invariants
Joint work with Pedro de Carvalho Cayres Pinto, Hans-Christian Herbig, and Daniel Herden
International Congress of Mathematicians (ICM 2018),
Rio de Janeiro, Brazil.
- May 7 10, 2018
The k-large property for representations of complex reductive groups and implications for linear symplectic quotients
Joint work with Hans-Christian Herbig and Gerald Schwarz
International Conference on Mathematics and Statistics (ICOMAS 2018),
University of Memphis, Tennessee.
- April 14 15, 2018
The Hilbert series of a reducible representation of SL2(C) and its Laurent coefficients
Joint work with Pedro de Carvalho Cayres Pinto, Hans-Christian Herbig, and Daniel Herden
Special Session on Commutative Algebra, Spring Southeastern Sectional Meeting of the AMS,
Nashville, Tennessee.
- November 11, 2017
Counting SL2(C)-invariant polynomials
Joint work with Pedro de Carvalho Cayres Pinto, Hans-Christian Herbig, and Daniel Herden
37th Annual Math Symposium at Western Kentucky University
Bowling Green, Kentucky.
- July 11, 2017
Complex symplectic quotients with symplectic singularities
Joint work with Hans-Christian Herbig and Gerald Schwarz
Instituto de Matem tica Pura e Aplicada (IMPA),
Rio de Janeiro, Brazil.
- April 22, 2017
The spectrum of orbifold connected sums and collapsing
Joint work with Emily Proctor and Carla Farsi
Methods in Operator Theory and Applications,
University of Memphis, Memphis, TN.
- July 11-15, 2016
Collaborate@ICERM: Hilbert Series of Sympletic Torus Quotients
With Hans-Christian Herbig and Daniel Herden
The Institute for Computational and Experimental Research in Mathematics (ICERM),
Providence, Rhode Island.
- March 15, 2016
Constructing symplectmorphisms between linear symplectic quotients
Joint work with Joshua Cape, Emily Cowie, Carla Farsi, Hans-Christian Herbig, Daniel Herden, Ethan Lawler, and Gerald Schwarz
Poisson Geometry Seminar, University of Colorado at Boulder,
Boulder, Colorado.
- March 11, 2016
The inertia groupoid of a Lie groupoid
Joint work with Carla Farsi and Markus Pflaum
Gone Fishing 2016, University of Colorado at Boulder,
Boulder, Colorado.
- March 5, 2016
The ring of regular functions on a linear symplectic quotient
Joint work with Joshua Cape, Hans-Christian Herbig, Daniel Herden, and Gerald Schwarz
Special Session on Symplectic and Contact Geometry, Spring Southeastern Sectional Meeting of the AMS,
Athens, Georgia.
- January 11-12, 2016
Minicursos Avancados (advanced minicourse): Computational methods in the study of symplectic quotients (four 90-minute lectures with Hans-Christian Herbig)
Instituto de Matemática, Universidade Federal do Rio de Janeiro,
Rio de Janeiro, Brazil.
- November 15, 2015
Coefficients of the Laurent expansion of the Hilbert series of Gorenstein rings
Joint work with Hans-Christian Herbig and Daniel Herden
4th Annual Mississippi Discrete Mathematics Workshop, University of Mississippi,
Oxford, Mississippi.
- July 10, 2015
Hilbert series of regular functions on singular symplectic quotients
Joint work with Joshua Cape, Emily Cowie, Carla Farsi, Hans-Christian Herbig, Daniel Herden, and Gerald Schwarz
Department of Mathematics, Baylor University,
Waco, Texas.
- July 20 24, 2015
Participant in the REUF Workshop at ICERM,
Providence, Rhode Island.
- January 6, 2015
Singular symplectic reduction and invariant theory
Joint work with Joshua Cape, Carla Farsi, Hans-Christian Herbig, Daniel Herden, and Gerald Schwarz
Instituto de Ciências Matemáticas e de Computação, Universidade de São Paulo,
São Carlos, Brazil.
- November 14, 2014
Differentiable stratified groupoids
Joint work with Carla Farsi and Markus Pflaum
University of Colorado at Boulder Groupoids Seminar,
Boulder, Colorado.
- August 11, 2014
Orbifold and non-orbifold symplectic quotients
Joint work with Carla Farsi, Hans-Christian Herbig, Daniel Herden, and Gerald Schwarz
Topology of Torus Actions and Applications to Geometry and Combinatorics,
Daejeon, Korea.
- March 13, 2014
Geometry of symplectic quotients via invariant theory II
Joint work with Carla Farsi, Hans-Christian Herbig, Daniel Herden, and Gerald Schwarz
Commutative Algebra Seminar, University of Nebraska at Lincoln,
Lincoln, Nebraska.
