## Talks that I have given (or will give)

For conferences that I organized rather than spoke at, click here.

#### 2024

December 16-20, Vertex algebras and related topics, Academia Sinica, Taipei.

The unitary cobordism hypothesis. November 12, SCGCS Annual Meeting Satellite Workshop, New York University. (abstract.)

The unitary cobordism hypothesis. November 5, Fields Geometry and Physics Seminar, University of Toronto. (abstract.)

Exact sequences of Hopf algebras. October 30, Geometry and Physics Seminar, Boston University. (abstract.)

The homotopy groups of a TQFT. October 22, Representation theory and tensor categories seminar, University of California, Berkeley. (abstract.)

Wormholes and an exact sequence. September 10, Applications of Generalized Symmetries and Topological Defects to Quantum Matter, Simons Center for Geometry and Physics, Stony Brook. (video.)

Quantum homotopy groups. June 17, Categorical Symmetries in Quantum Field Theory, International Centre for Mathematical Sciences, Edinburgh. (abstract. video.)

Quantum homotopy groups. June 12, Thematic Program in Field Theory and Topology, University of Notre Dame. (abstract. video.)

The universal target category. May 2, Workshop on Global Categorical Symmetries, Center of Mathematical Sciences and Applications, Harvard University. (abstract. slides.)

The universal target category. April 11, Topology Seminar, Johns Hopkins University. (abstract. notes.)

Quantum homotopy groups. March 21, Higher Categorical Tools for Quantum Phases of Matter, Perimeter Institute for Theoretical Physics. (abstract. slides. video.)

Recent progress on the classification of fusion higher categories. SCGCS internal meeting, Zoom. (slides.)

#### 2023

Dagger Categories. December 14, SCGCS Collaboration Assembly, Zoom. (video.)

Higher Dagger Categories. November 8, Geometry, Topology & Physics Seminar, New York University Abu Dhabi. (abstract. slides.)

Deeper Kummer theory. September 21, Mathematical Physics Seminar, Perimeter Institute. (abstract. video.)

Quantum Homotopy Types. September 11, Researcher Presentations for New PSI Students, Perimeter Institute. (slides.)

SVOAs and some exceptional groups. August 22, Universität Hamburg. (abstract.)

Super Duper Vector Spaces II: The higher-categorical Galois group of

**R**. August 18, Higher Structures in Functorial Field Theory, University of Regensburg. (abstract. notes.)Topological Umbral Moonshine. July 17-21, Topological Moonshine, UIUC. (notes.)

Higher algebraic closure. May 19, OWSM Seminar, Mathematics Institute, Oxford. (abstract.)

Higher algebraic closure. April 27, Colloquium, The Ohio State University. (abstract. slides. video.)

Higher algebraic closure. April 11, Higher Structures Seminar, Feza Gürsey Institute. (abstract. slides.)

#### 2022

Homotopy Quantum Groups. November 18, 2022 Simons Collaboration on Global Categorical Symmetries Annual Meeting, Simons Foundation. (abstract. slides. video.)

SVOAs and some exceptional groups. October 25, Quantum Symmetries, Centre de Recherches Mathématics. (abstract. video. notes.)

Hypergroups and fusion higher categories. October 6, Mathematical Physics Group Meeting, Perimeter Institute. (abstract.)

A 4D TQFT which is not (quite) a gauge theory. October 4, Symmetry Seminar, Oxford. (abstract. slides. video.)

Hypergroups and fusion higher categories. September 29, Higher categories and topological order, AIM. (notes.)

Global categorical symmetry and higher fusion categories. September 19, PSI faculty presentations, Perimeter Institute. (slides.)

What is a fusion higher category? September 9, Higher Symmetry and Quantum Field Theory, Aspen Center for Physics.

Classification of (semisimple) TQFTs. March 29, Math QFT seminar, MPIM. (abstract. slides.)

Why the spaces of N=(0,1) susy QFTs form a spectrum? March 7, Stolz–Teichner Seminar, Oxford. (slides)

Categorified algebraic closure. February 15, ATCAT, Dalhousie. (abstract. notes. video.)

#### 2021

Algebraically closed higher categories. December 5, Geometry and Topology Seminar, Haifa. (abstract. slides. video.)

Algebraically closed higher categories. December 3, Mathematical Physics Seminar, Perimeter Institute. (abstract. video.)

Classification of topological quantum field theories. November 18, CTP Seminar, QMUL. (abstract. slides.)

TMF and SQFT: questions and conjectures. November 4, Generalized Cohomology and Physics, ICTP. (abstract. slides. video.)

The Monster. October 27, Honours Seminar, Dalhousie. (abstract.)

A menagerie of N=1 SVOAs. October 6, NAAP, Kavli IPMU. (abstract. slides.)

Semisimple higher categories. July 26, Western Hemisphere Colloquium on Geometry and Physics. (abstract. slides. video.)

Operators and (higher) categories in quantum field theory. July 19-23, Seminar on Arithmetic Geometry and Quantum Field Theory, Korea Institute for Advanced Study. (abstract. digital chalk boards: I, II, III, IV, V. videos: I, II [first five minutes] and II, III, IV, V.)

Higher S-matrices. June 18, TQFT Club, Instituto Superior Técnico. (abstract. slides. video.)

Minimal nondegenerate extensions. June 11, Fusion Friday, AIM. (notes. video.)

Minimal nondegenerate extensions and an anomaly indicator. June 10, Quantum Matter in Mathematics and Physics, CMSA, Harvard. (abstract. slides. video.)

Classification of topological orders. June 9, Quantum Mathematics: Quantum Matter and Quantum Information, 75+1 CMS Summer Meeting. (abstract. slides. video.)

Higher S-matrices. May 20, Higher Structures & Field Theory Seminar, UniVie/Erlangen/Würzburg/TUM. (abstract. slides.)

The classification of topological orders. April 1, Mathematics Department Colloquium, OSU. (abstract. slides. pretalk slides.)

Fusion n-category Q&A. March 12, Fusion categories and tensor networks, AIM.

Orbifolds. March 4, Moonshine Learning Seminar, IAS. (prepared typed notes. live hand-written slides.)

Higher Galois closures. March 3, AGQFT, University of Warwick. (abstract. slides. video.)

Strongly-fusion 2-categories are grouplike. March 1, Representation Theory Seminar, UMass Amherst. (abstract. slides. video.)

Condensations and components. February 18, University Quantum Symmetries Lectures, NCSU. (abstract. slides.)

#### 2020

A topological umbral moonshine conjecture. November 17, Modularity in Quantum Systems, Kavli Institute for Theoretical Physics. (abstract. slides. video.)

Holomorphic SCFTs of small index. November 13, Topology, Algebraic Geometry, and Dynamics Seminar, George Mason University. (abstract. slides.)

Pseudounitary slightly degenerate braided fusion categories admit minimal modular extensions. November 10, Wales Mathematical Physics and Physical Mathematics, Cardiff University. (abstract. slides.)

Some examples in fusion 2-categories and 3+1D topological order. November 6, Global Categorical Symmetries Seminar. (abstract. slides. video.)

3+1d topological orders with (only) an emergent fermion. October 26, Heidelberg-Munich-Vienna Seminar on Mathematical Physics. (abstract. slides.)

3+1d topological orders with (only) an emergent fermion. October 20, Representation Theory and Mathematical Physics, UC Berkeley. (abstract.)

Separable and central simple (higher) algebras. October 13, ATCAT, Dalhousie. (abstract. slides.)

Algebraic definition of topological order. August 7, Topological Orders and Higher Structures, ESI Vienna. (abstract. slides. video.)

Mock modularity and a secondary invariant. July 31, String Math 2020, Stellenbosch University, South Africa. (abstract. slides. video.)

SPT phases and generalized cohomology. June 23, Algebraic structures in quantum computation IV, UBC. (abstract. slides. video.)

Phases of SQFTs. June 8, Mathematics Colloquium, Dalhousie. (abstract. slides.)

On the classification of topological phases. June 1, Colloquium, Perimeter Institute. (abstract. slides. video.)

Gapped condensation in higher categories. March 17, Tensor categories and topological quantum field theories, MSRI. (abstract. video.)

A deformation invariant of 2D SQFTs. February 25, New High Energy Theory Center Seminar, Rutgers. (abstract. video.)

A deformation invariant of 2D SQFTs. January 24, Geometry, Topology, and Physics, UC Santa Barbara. (abstract. audio. notes by Dave Morrison.)

A deformation invariant of 1+1D SQFTs. January 14, Quantum Fields and Strings, Perimeter Institute. (abstract. video.)

#### 2019

A deformation invariant of 2D SQFTs. December 11, Diff. Geom, Math. Phys., PDE Seminar, UBC. (abstract. notes.)

Spaces of quantum systems. December 10, Department Colloquium, UBC. (abstract. slides.)

The Monstrous Moonshine Anomaly. November 27, Cohomology of Groups Seminar, Perimeter Institute. (abstract. video. notes.)

Condensation in higher categories. November 20, Higher Structures in Geometry and Physics, Fields Institute. (abstract. video.)

TMF and SQFT. November 18. High Energy Theory Seminar, IAS, Princeton. (abstract. video.)

Bott periodicity from quantum Hamiltonian reduction. October 24. Colloquium, Dalhousie University, Halifax. (abstract.)

Condensation and idempotent completion. October 22. ATCAT Seminar, Dalhousie University, Halifax. (abstract.)

Bott periodicity from quantum Hamiltonian reduction. September 16. McGill. (abstract.)

Phases of 2d SQFTs. August 9. Generalized Symmetries, Anomalies and Observables, Aspen Center for Physics. (notes. abstract.)

Exceptional Mathematics: from Egyptian fractions to heterotic strings. July 23. Colloquium, Canada/USA Mathcamp. (slides without animation (8MB), slides with embedded video (best viewed in Acrobat Reader, 200MB), slides in handout format. abstract.)

0D QFT and Feynman diagrams. June 17. QFT for Mathematicians, Perimeter Institute. (notes, video.)

Secondary invariants and mock modularity. May 27. Topology Seminar, Oxford. (abstract.)

The Galois action on VOA anomalies. March 18. Higher Symmetries Conference 2019, Aspen Center for Physics. (abstract.)

Galois actions on VOA gauge anomalies. February 27. Conference on Number Theory, Geometry, Moonshine & Strings III. Simons Foundation, NYC. (abstract. video available from conference website)

Bott periodicity from quantum Hamiltonian reduction. February 25. Analysis & PDE Seminar, Stanford. (abstract.)

Galois actions on VOA gauge anomalies. February 22. Alg No Th Seminar, UCSC. (abstract.)

Bott periodicity from quantum Hamiltonian reduction. February 19. Colloquium, UCSC. (abstract.)

#### 2018

Poisson and coisotropic. November 21 and December 12 (three-hour lecture). Koszul Duality Seminar, PITP. (abstract. video of first hour. video of third hour (self-contained).)

Holomorphic SCFTs of small index. November 27. Quantum Algebra and Quantum Topology, OSU. (abstract.)

Holomorphic SCFTs of small index. November 8. Mathematical Physics, UIUC. (abstract.)

Galois action on gauge anomalies. October 18. Fusion Categories and Subfactors, BIRS, Banff, Canada. (abstract. video.)

T-duality for finite groups. June 4. Representation Theory, Mathematical Physics and Integrable Systems, CIRM, Luminy, France. (abstract. notes.)

The fourth cohomology of some sporadic groups. April 17. Geometry, Symmetry and Physics, Yale. (abstract.)

Moonshine anomalies. April 9. Algebra seminar, University at Buffalo. (abstract.)

Infinitely-categorified commutative algebra. March 17--19. Recent developments in noncommutative algebra and related areas, University of Washington. (abstract.)

Moonshine anomalies. February 9. QMAP seminar, UC Davis. (abstract.)

Higher algebraic closures and phases of matter. January 22. Northeastern University. (abstract. handout.)

Moonshine anomalies. January 19. UT Austin. (abstract.)

#### 2017

Higher categories, generalized cohomology, and condensed matter. November 15. Representation Theory and Mathematical Physics, UC Berkeley. (abstract. notes.)

576 Fermions. October 24. Algebra Seminar, Emory. (abstract.)

Bott periodicity from Hamiltonian reduction. October 5. NT&AG, Boston College. (abstract.)

Exceptional structures, fermions, anomalies, and Hamiltonian reduction. October 3. Research Seminar in Mathematics, Northeastern. (abstract. notes.)

The Moonshine Anomaly. July 25. Higher Structures Lisbon, Instituto Superior Técnico, Lisbon, 24–27 July 2017. (abstract.)

The Moonshine Anomaly. July 19. Maximals Seminar, University of Edinburgh. (abstract.)

Orbifolds of conformal field theories and cohomology of sporadic groups. April 14. RTGC Seminar, UC Berkeley. (abstract. notes.)

Advanced integration by parts: the BV formalism. Feb 9. Geometric Structures Laboratory, Fields Institute. (abstract. notes.)

Fermionic hamiltonian reduction and periodicity. Feb 1. Geometry and Physics Seminar, Boston University. (abstract.)

Ideals in derived algebra and boundary conditions in AKSZ-type field theories. Jan 27. RTGC Seminar, UC Berkeley. (abstract. notes.)

#### 2016

576 fermions, the Conway group, and tmf. Sept 27. Institute for Theoretical Physics, Stanford.

Moonshine, topological modular forms, and 576 fermions. Sept 22, Mathematical Physics Seminar, Perimeter Institute. (abstract. video.)

Bott periodicity via quantum Hamiltonian reduction. Sept 2, Representation Theory, Geometry, and Combinatorics Seminar, UC Berkeley. (abstract)

Bott periodicity via quantum Hamiltonian reduction. May 12, Factorization Algebras and Functorial Field Theories meeting, Oberwolfach. (abstract, notes)

"Spin-statistics" is a categorification of "Hermitian". February 22, RTGC Seminar, Berkeley. (abstract, handout)

#### 2015

Where does the Spin-Statistics Theorem come from?. November 23, Geometry, Topology and Dynamics Seminar, UIC. (abstract, handout)

Spin--Statistics and Categorified Galois Groups. October 23, Conference on Condensed Matter Physics and Topological Field Theory, Perimeter Institute. (abstract, handout)

A higher category theorist's take on the spin--statistics theorem. September 28, Topology Seminar, UIUC. (abstract, handout)

The Stokes groupoids of Gualtieri, Li, and Pym. May 4&6, Math 448: Topics in Geometry and Topology, Northwestern. (abstract, notes)

Some non-dualizable categories. April 17, Representation Theory, Geometry, and Combinatorics, UC Berkeley. (abstract, handout)

Local Poincare duality & deformation quantization. April 2, Center for Geometry and Physics, Institute for Basic Science, Pohang, South Korea. (abstract, handout, video (follow talk link))

Some comments on Heisenberg-picture qft. March 18, Max Planck Institute for Mathematics, Bonn, Germany. (abstract, handout)

Twisted field theories and higher-categorical (op)lax transfors. March 3, Topology Seminar, University of Notre Dame, South Bend, IN. (abstract, handout)

Functorial axioms for Heisenberg-picture quantum field theory. January 12, CRG Geometry and Physics Seminar, UBC, Vancouver, BC. (abstract, handout)

#### 2014

Heisenberg-picture quantum field theory. November 17, Quantum Mondays Seminar, Center for Geometry and Physics, Institute for Basic Science, Pohang, South Korea. (abstract, video (follow talk link))

The CS-WZW correspondence. October 30, CFT Seminar, Northwestern University, Evanston, IL. (abstract, notes)

Poisson AKSZ theories. October 3, Homological Methods in Quantum Field Theory, Simons Center for Geometry and Physics, Stony Brook, NY. (abstract, outline, video, live-TeX'ed notes by Gabriel C. Drummond-Cole)

Lie bialgebra quantization in 2- and 3-dimensional field theory. May 28, Associators, Formality and Invariants Seminar, Northwestern, Evanston, IL. (abstract, notes)

The Jones polynomial and the Temperley--Lieb TQFT. May 9, Graduate Student Seminar, Northwestern, Evanston, IL. (abstract, notes)

Heisenberg-picture TQFTs. May 2, Representation Theory, Geometry, and Combinatorics, UC Berkeley. (abstract, notes)

Poisson AKSZ theory and homotopy actions of properads. February 21, Modern trends in topological quantum field theory, Erwin Schrödinger International Institute for Mathematical Physics. (abstract, handout)

Up-to-homotopy Frobenius structures on manifolds, and how they relate to perturbative QFT. January 22, Topology Seminar, UC Berkeley. (abstract, handout)

#### 2013

Poisson AKSZ theories and quantization. October 24, Geometry Seminar, UT Austin. (abstract, handout)

Poisson AKSZ theories and quantization. October 12, Higher Structures in Algebra, Geometry and Physics, Fall Eastern Sectional Meeting of the AMS, Temple University, Philadelphia. (abstract, handout)

Poisson AKSZ theory, properads, and quantization. October 10, Geometry and Physics, Northwestern, Evanston. (abstract, handout)

A properad action on homology that fails to lift to the chain level. October 10, Geometry and Physics Pre-talk, Northwestern, Evanston. (abstract, handout)

A properadic approach to the deformation quantization of topological field theories. September 25, Algebra and Combinatorics, Loyola University, Chicago. (abstract, notes)

A salad of BV integrals and AKSZ field theories, served over a bed of properads; it comes spiced with chain-level Poincare duality and just a pinch of Poisson geometry. September 10, Research Seminar in Mathematics, Northeastern University, Boston. (abstract, notes)

Star quantization via lattice topological field theory. June 18, String-Math, Simons Center for Geometry and Physics, Stony Brook. (abstract, slides)

Lattice Poisson AKSZ Theory. February 4, Algebraic Geometry Seminar, University of British Columbia. (abstract, handout)

#### 2012

Feynman diagrams for quantum mechanics. October 10–12, Topics in Applied Mathematics, UC Berkeley. (abstract, notes)

Nonperturbative integrals, imaginary critical points, and homological perturbation theory. August 28, New Perspectives in Topological Field Theories, Center for Mathematical Physics, Hamburg. (abstract, notes)

Nonperturbative integrals, imaginary critical points, and homological perturbation theory. August 24, QGM Lunch Seminar, Aarhus. (abstract, notes)

Wick-type theorems beyond the Gaussian. March 2, Representation Theory (and related topics) seminar, Northeastern. (abstract, handout, notes)

Twisted N=1 and N=2 supersymmetry on R^4. February 10, GRASP seminar, UC Berkeley. (abstract, notes)

#### 2011

Notes on Floer / Gromov–Witten TQFT, based on conversations with Zack Sylvan. November 15, Witten in the 80s, UC Berkeley. (notes)

Gauge-fixed integrals for Lie algebroids. November 1, Talks in Mathematical Physics, Universität Zürich & Eidgenössische Technische Hochschule Zürich. (abstract, handout)

Introduction to BV Integrals. November 1, Selected topics in classical and quantum geometry, Universität Zürich. (abstract, handout)

Asymptotics of oscillating integrals via homological perturbation theory. October 19, GRASP seminar, UC Berkeley. (abstract, handwritten notes, too-long typed notes)

BRST Gauge Fixing: I. Introduction to Q-manifolds and BRST. II. Chern-Gauss-Bonnet, Morse Theory, and topological sigma models. October 11-20, Witten in the 80s, UC Berkeley. (abstract, notes I, notes II)

(Topological) duality of Hopf algebras. June 13, Cluster Algebras and Lusztig's Semicanonical Basis, University of Oregon. (abstract, notes)

Homological perturbation and factorization algebras. May 26, Geometry/Physics Seminar, Northwestern University. (abstract, notes)

On Atoms, Mountains, and Rain. April 20, NUMS Seminar, Northwestern University. (abstract)

Feynman Diagrams for Schrodinger's Equation. Feb 15, GADGET Seminar, UT Austin. (abstract, handout)

E

_{2}operad, Gerstenhaber and BV, and Formality. Feb 10, Student String Topology Seminar, UC Berkeley. (abstract, notes, handout)

#### 2010

Crash course in Tannaka-Krein theory. Dec 3, Student Subfactors Seminar, UC Berkeley. (abstract, notes)

Formal calculus, with applications to quantum mechanics. Sept 10, GRASP seminar, UC Berkeley. (abstract, notes).

Introduction to Vassiliev invariants. April 2, GRASP seminar, UC Berkeley. (abstract).

How to quantize infinitesimally-braided symmetric monoidal categories. March 19, Subfactors Seminar, UC Berkeley. (abstract, notes).

The Formal Path Integral in Quantum Mechanics. Feb 26, Subfactors Seminar, UC Berkeley. (abstract, slides).

#### 2009

What the Hell is a Feynman Diagram? Sept 29, Ph.d. seminar, Institut for Matematiske Fag, Aarhus Universitet. (abstract, notes).

On Atoms, Mountains, and Rain. March 31, Many Cheerful Facts, UC Berkeley. (abstract, notes).

#### 2007

Enriching Yoneda. December 11, QFT Mini Conference, UC Berkeley. (abstract, notes).

Divergent Series. October 18, Many Cheerful Facts, UC Berkeley. (abstract, notes).