Christopher W. Seaton


 

Professor, Department of Mathematics and Statistics
(formerly the Department of Mathematics and Computer Science)

 

 

CUR Mathematics and Computer Sciences Division 2021 Advanced Career Faculty Mentor Award

 

Contact:

Teaching (Spring 2024):

Office Hours (Spring 2024):

Office:

Ohlendorf 320

(course materials available on Canvas)

 

Math 116-01: Calculus with Business Applications

 

E-mail:

(the best way to reach me):

seatonc-at-rhodes-dot-edu


Monday: 1 2:20 pm

Wednesday: 11 11:50 am

Friday: 12:30 1:50 pm

Phone:

901-843-3721

Math 362-01/2: Abstract Algebra I

 

Snail Mail:

Math & Computer Science

Rhodes College

2000 N. Parkway

Memphis, TN 38112, USA

Math 452-02: Research in Mathematics


Math 386-01/2: Junior Seminar


Math 486-01: Senior Seminar


Students are welcome and encouraged to make appointments at other times if my office hours are not convenient. The best way to do this is via e-mail.
I am happy to meet (during office hours or otherwise) via Zoom. Just email me so we can set this up.

 
 
Weekly Schedule


C. V.

 


 

Math 115: Applied Calculus Course Development Materials

Some Slides from Groupoidfest 2015 (Special Session on The Analysis, Topology, and Geometry of Groupoids, Fall Southeastern Sectional Meeting of the AMS)


 
 
Publications and Preprints:
(click here for some supplemental materials)

 

A universal Euler characteristic of non-orbifold groupoids and Riemannian structures on Lie groupoids.
(with Carla Farsi and Emily Proctor; preprint)

 

Euler characteristics of linear symplectic quotients and O(2)-spaces
(with Carla Farsi and Hannah Meit; submitted)

 

A symmetric function approach to polynomial regression.
(with Hans-Christian Herbig and Daniel Herden; submitted)

 

Isomorphisms of symplectic torus quotients.
(with Hans-Christian Herbig and Gerald Schwarz; to appear in the Journal of Symplectic Geometry)

 

When does the zero fiber of the moment map have rational singularities?
(with Hans-Christian Herbig and Gerald Schwarz; to appear in Geometry & Topology)

 

Multigraded Hilbert series of invariants, covariants, and symplectic quotients for some rank 1 Lie groups
(with Austin Barringer, Hans-Christian Herbig, Daniel Herden, Saad Khalid, and Lawton Walker; Communications in Algebra 52 (2024) 1000--1027)

 

Higher Koszul brackets on the cotangent complex
(with Hans-Christian Herbig and Daniel Herden; International Mathematics Research Notices 2023, Issue 13 (2023) 11592--11644)

 

Hilbert series of symplectic quotients by the 2-torus
(with Hans-Christian Herbig and Daniel Herden; Collectanea Mathematica) 74 (2023) 415--442)

 

Differentiable stratified groupoids and a de Rham theorem for inertia spaces
(with Carla Farsi and Markus Pflaum; Journal of Geometry and Physics 187 (2023), 104806)

 

Orbifold Euler characteristics of non-orbifold groupoids
(with Carla Farsi; Journal of the London Mathematical Society) 106 (2022), 2342--2378)

 

The spectra of digraphs with Morita equivalent C*-algebras
(with Carla Farsi and Emily Proctor; Linear Algebra and its Applications 655 (2022), 28--64)

 

Approximating orbifold spectra using collapsing connected sums
(with Carla Farsi and Emily Proctor; Journal of Geometric Analysis 31 (2021), 9433--9468)

 

The Laurent coefficients of the Hilbert series of a Gorenstein algebra
(with Hans-Christian Herbig and Daniel Herden; Experimental Mathematics 30 (2021), 56--75)

 

Constructing symplectomorphisms between symplectic torus quotients
(with Hans-Christian Herbig and Ethan Lawler; Beiträge zur Algebra und Geometrie / Contributions to Algebra and Geometry 61 (2020), 581--604)

 

Hilbert series associated to symplectic quotients by SU2
(with Hans-Christian Herbig and Daniel Herden; International Journal of Algebra and Computation 30 (2020), 1323--1357)

 

The Hilbert series of SL2-invariants
(with Pedro de Carvalho Cayres Pinto, Hans-Christian Herbig, and Daniel Herden; Communications in Contemporary Mathematics 22 (2020) 1950017)

 

Symplectic quotients have symplectic singularities
(with Hans-Christian Herbig and Gerald Schwarz; Compositio Mathematica 156 (2020), 613--646)

 

The Hilbert series and a-invariant of circle invariants
(with L. Emily Cowie, Hans-Christian Herbig, and Daniel Herden; Journal of Pure and Applied Algebra 223 (2019), 395--421)

 

Functional equations for orbifold wreath products
(with Carla Farsi; Journal of Geometry and Physics 120 (2017), 37--51)

 

Symplectic reduction at zero angular momentum

(with Joshua Cape and Hans-Christian Herbig; Journal of Geometric Mechanics 8 (2016), 13--34)


On compositions with x^2/(1-x)
(with Hans-Christian Herbig and Daniel Herden; Proceedings of the American Mathematical Society 143 (2015), 4583--4596) 


An impossibility theorem for linear symplectic circle quotients
(with Hans-Christian Herbig; Reports on Mathematical Physics 75 (2015), 303--331)
 

When is a symplectic quotient an orbifold?
(with Hans-Christian Herbig and Gerald Schwarz; Advances in Mathematics 280 (2015), 208--224)

 

Stratifications of inertia spaces of compact Lie group actions
(with Carla Farsi and Markus Pflaum; Journal of Singularities 13 (2015), 107--140)

Gauge-fixing on the lattice via orbifolding
(with Dhagash Mehta, Noah S. Daleo, and Jonathan D. Hauenstein; Physical Review D 90 (2014), 054504)

Gamma-extensions of the spectrum of an orbifold
(with Carla Farsi and Emily Proctor; Transactions of the American Mathematical Society 366 (2014), 3881--3905)

The Hilbert series of a linear symplectic circle quotient
(with Hans-Christian Herbig; Experimental Mathematics 23 (2014), 46--65)

An orbit Cartan type decomposition of the inertia space of SO(2m) acting on R2m
(with John Wells, Involve: a Journal of Mathematics 6 (2013), 345--368)

Extensions of the Euler-Satake characteristic for nonorientable 3-orbifolds and indistinguishable examples
(with Ryan Carroll, Involve: a Journal of Mathematics 6 (2013), 467--482)

On orbifold criteria for symplectic toric quotients
(with Carla Farsi and Hans-Christian Herbig, Symmetry, Integrability, and Geometry 9 (2013), 032, 33 pages)

Extensions of the Euler-Satake characteristic and point singularities of orientable 3-orbifolds
(with Ryan Carroll; Kodai Mathematical Journal 36 (2013), 179--188)

Algebraic structures associated to orbifold wreath products
(with Carla Farsi; Journal of K-Theory 8 (2011), 323--338)

Free and free abelian Euler-Satake characteristics of nonorientable 2-orbifolds
(with John Schulte and Bradford Taylor; Topology and its Applications 158 (2011), 2244--2255)

Generalized orbifold Euler characteristics for general orbifolds and wreath products
(with Carla Farsi; Algebraic and Geometric Topology 11 (2011), 523--551)

Classifying closed 2-orbifolds with Euler characteristics
(with Whitney DuVal, John Schulte, and Bradford Taylor; Glasgow Mathematical Journal 52 (2010), no. 3, 555--574)

Generalized twisted sectors of orbifolds
(with Carla Farsi; Pacific Journal of Mathematics 246 (2010), no. 1, 49--74)

Nonvanishing vector fields on orbifolds
(with Carla Farsi; Transactions of the American Mathematical Society 362 (2010), 509--535)

The index of a vector field on an orbifold with boundary
(with Elliot Paquette; Involve: a Journal of Mathematics 2 (2009), no. 2, 161--175)

Two Gauss-Bonnet and Poincar -Hopf theorems for orbifolds with boundary
(Differential Geometry and its Applications 26 (2008), no. 1, 42--51)

K-theory of crepant resolutions of complex orbifolds with SU(2) singularities
(Rocky Mountain Journal of Mathematics 37 (2007), no. 5, 1705--1712)

Characteristic classes of bad orbifold vector bundles
(Journal of Geometry and Physics 57 (2007), no. 11, 2365--2371)

A complete obstruction to the existence of nonvanishing vector fields on almost-complex, closed cyclic orbifolds

 

 

 

Recent/Upcoming Presentations/Workshops:

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 (remote)

Rational singularities of the zero fiber of the moment map, symplectic quotients, and applications to representation and character varieties of surface groups

Joint work with Hans-Christian Herbig and Gerald Schwarz

Baylor University Mathematics Colloquium,

Baylor University, Texas.

 

November 3, 2020 (remote)

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

Semin rio Simpl tico 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), cole Polytechnique F d rale 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

CIRM (Centre International de Rencontres Math matiques)

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 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

Vanderbilt University, 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, Colorado

 

March 10 13, 2016

The inertia groupoid of a Lie groupoid,

Joint work with Carla Farsi and Markus Pflaum

Gone Fishing Poisson Geometry Conference

University of Colorado at 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

University of Georgia, Athens, Georgia



January 11 12, 2016
Minicursos Avan ados (advanced minicourse): Computational methods in the study of symplectic quotients
Four 90-minute lectures (with Hans-Christian Herbig)
Instituto de Matem tica, Universidade Federal do Rio de Janeiro, Brazil.

Click Here for the slides.

 

November 14 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

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 Ci ncias Matem ticas e de Computa o. Universidade de S o Paulo. S o 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 Convention Center, 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 NE

 

October 19, 2013

The inertia space of a proper Lie groupoid as a stratified differentiable space

Joint work with Carla Farsi and Markus Pflaum

Fall Central Sectional Meeting of the AMS,

Washington University, St. Louis, MO

 

April 14, 2013

The inertia space associated to a proper Lie group action as a stratified space

Joint work with Carla Farsi and Markus Pflaum

Spring Western Sectional Meeting of the AMS,

University of Colorado at Boulder, Boulder, CO

 

September 12, 2012

A stratification of the orbit space of a G-manifold for a compact Lie group G

Joint work with Carla Farsi and Markus Pflaum

Centre for Quantum Geometry and Moduli Spaces,

Aarhus University, Aarhus Denmark

 

January 21 22, 2012

An explicit stratification of the inertia space for  a connected, compact Lie group action

Joint work with Carla Farsi and Markus Pflaum

Groupoidfest 2011,

University of Nevada, Reno

Reno, NV

 

July 28, 2011

On orbifold criteria for Hamiltonian toric quotients

Joint work with Carla Farsi and Hans-Christian Herbig

Workshop on Recent developments on Orbifolds

Chern Institute of Mathematics

Tianjin, China