Codes and Expansions (CodEx) Seminar

A pan-university, remote seminar on the theory and applications of harmonic analysis, combinatorics, and algebra.

Tuesdays at 10 a.m. PST / 1 p.m. EST / 6 p.m. UTC / 7 p.m. CET

Zoom. To access the Zoom link, please join the mailing list by entering your information here.

Recorded talks are on our YouTube channel.

Organized by:
Joey Iverson (Iowa State University)
John Jasper (South Dakota State University)
Emily J. King (Colorado State University)
Dustin Mixon (The Ohio State University)

Upcoming talks:

February 1, 2022Henry Adams (Colorado State University): "The topology of projective codes" Abstract
February 8, 2022Darrin Speegle (Saint Louis University)
February 15, 2022Tim Kunisky (Yale University)
February 22, 2022[SPECIAL TIME: 3 p.m. PST / 6 p.m. EST / 11 p.m. UTC / Midnight CET] Sho Suda (National Defense Academy of Japan)
March 1, 2022Jonathan Jedwab (Simon Fraser University)
March 8, 2022Igor Balla (Hebrew University of Jerusalem)
March 15, 2022Sinan Gunturk (New York University)
March 22, 2022Soledad Villar (Johns Hopkins University)
March 29, 2022Felix Krahmer (Technische Universität München)
April 5, 2022
April 12, 2022Hau-Tieng Wu (Duke University)
April 17, 2022Simon Foucart (Texas A&M University)
April 19, 2022Deanna Needell (University of California Los Angeles)
April 26, 2022Doug Hardin (Vanderbilt University)
May 3, 2022Amit Singer (Princeton University)

Past talks:

January 25, 2022Lutz Warnke (University of California San Diego): "The Density of Costas Arrays Decays Exponentially" Abstract | Video
January 18, 2022Bernd Sturmfels (University of California Berkeley and Max Planck Institute for Mathematics in the Sciences Leipzig): "Linear PDE with Constant Coefficients" Abstract | Slides
December 7, 2021Rima Alaifari (ETH Zürich): "(Non-)uniqueness of phase recovery from Gabor and wavelet transform measurements" Abstract | Video
November 30, 2021Dan Edidin (University of Missouri): "Dihedral multi-reference alignment" Abstract | Video | Slides
November 16, 2021Wojciech Czaja (University of Maryland): "Fourier Scattering as Efficient Feature Extraction" Abstract | Video
November 9, 2021Monika Dörfler (Universität Wien): "Structure and Effective Dimensionality of Time Series Data Sets" Abstract
November 2, 2021Alexander Powell (Vanderbilt University): "Dynamical Duals and Error Diffusion" Abstract
October 26, 2021Markus Grassl (International Centre for Theory of Quantum Technologies, University of Gdańsk): "Computing SIC-POVMs using Permutation Symmetries and Stark Units" Abstract | Video | Slides
October 19, 2021Joey Iverson (Iowa State University): "Equiangular lines over finite fields" Abstract | Video | Slides
October 12, 2021Clay Shonkwiler (Colorado State University): "A Lie Algebraic Perspective on Frame Theory" Abstract | Video
October 5, 2021X.Y. Han (Cornell University): "Prevalence of Neural Collapse during the terminal phase of deep learning training" Abstract | Video
September 28, 2021Boumediene Et-Taoui (Université de Haute Alsace): "A survey on complex conference matrices" Abstract | Video | Slides
September 21, 2021Naoki Saito (University of California Davis): "Multiscale Graph Basis Dictionaries" Abstract | Video
September 14, 2021Tom Needham (Florida State University): "Applications of Symplectic Geometry to Frame Theory" Abstract | Video | Slides
September 7, 2021Armenak Petrosyan (Georgia Institute of Technology): "Integral neural networks with weight penalization" Abstract | Video
August 31, 2021Mauro Maggioni (Johns Hopkins University): "Learning Interaction laws in particle- and agent-based systems" Abstract | Video
August 24, 2021Longxiu Huang (University of California Los Angeles): "CUR Decompositions and their Applications" Abstract | Video
August 10, 2021‪Romanos Diogenes-Malikiosis (Aristotle University of Thessaloniki): "Recent developments in the discrete Fuglede conjecture" Abstract | Slides | Video
August 3, 2021Matt Herman (Fourier Genetics): "Fourier Analysis on the Genome" Abstract | Video | Slides
July 27, 2021Nate Strawn (Georgetown University): "3D Filament Plots from Optimally Smooth 2D Andrew's Plots" Abstract | Slides | Video
July 13, 2021Davi Castro-Silva (Universität zu Köln): "Geometrical sets with forbidden configurations" Abstract | Video | Slides
July 6, 2021Nathan Lindzey (University of Colorado Boulder): "Discrete Harmonic Analysis on Matchings" Abstract | Video
June 29, 2021Xuemei Chen (University of North Carolina Wilmington): "Frame optimization with projective Riesz kernel" Abstract | Video
June 22, 2021Nadiia Derevianko (Universität Göttingen): "Estimation of Signal Parameters by Iterative Rational Approximation" Abstract | Video
June 15, 2021Michael Perlmutter (University of California Los Angeles): "Convolutional Networks on (Directed) Graphs via the Graph Fourier Transform" Abstract | Video | Slides
June 8, 2021Mikhail Ganzhinov (Aalto University): "Infinite families of optimal biangular line packings" Abstract | Video
June 1, 2021Joseph Cummings (University of Kentucky): "Phylogenetic Networks" Abstract | Video
May 25, 2021Elina Robeva (University of British Columbia): "Orthogonal and Incoherent Tensor decomposition" Abstract | Video
May 18, 2021Radu Balan (University of Maryland):"Embeddings of Metric Spaces induced by Permutation Groups" Abstract | Video
May 11, 2021Steve Butler (Iowa State University): "Hadamard diagonalizable graphs of small order" Abstract | Video
May 4, 2021Cynthia Vinzant (North Carolina State University): "The geometry of spectrahedra" Abstract | Video | Slides
April 27, 2021Azita Mayeli (City University of New York, the Graduate Center): "Exponential completeness and φ-approximate orthogonality on the unit ball" Abstract
April 20, 2021Marcin Bownik (University of Oregon): "Multiplication-invariant operators and the classification of abelian group frames" Abstract | Video | Slides
April 13, 2021Gary Greaves (Nanyang Technological University): "Real equiangular line systems in low dimensions" Abstract | Video | Slides
April 6, 2021Robert Calderbank (Duke University): "Coherent Noise" Abstract |
March 30, 2021Vignon Oussa (Bridgewater State University): "Why are topics such as differential geometry and representation theory useful to frame theory?" Abstract | Video
March 23, 2021Zilin Jiang (Arizona State University): "Spherical two-distance sets and spectral theory of signed graphs" Abstract " Video
March 16, 2021Daniel Freeman (St Louis University): "Discretizing L_p norms" Abstract | Video
March 9, 2021Keaton Hamm (The University of Texas at Arlington): "Column Selection and You" Abstract | Video
March 2, 2021Ram Zamir (Tel Aviv University): "Asymptotic Frame Theory for Analog Coding" Abstract | Video | Slides
February 23, 2021Joshua A. Grochow (University of Colorado Boulder): "Codes and Expansions in Algorithms for Matrix Multiplication" Abstract | Video | Slides
February 16, 2021Karin Schnass (Universität Innsbruck): "Random submatrices with non-uniformly distributed supports" Abstract | Video
February 9, 2021Eugenio Hernández (Universidad Autónoma de Madrid): "Spaces invariant under unitary representations and the bracket" Abstract | Slides | Video
February 2, 2021Emily J. King (Colorado State University): "A Potpourri of Projective 2-Designs" Abstract | Video | Slides
January 26, 2021Steven Flammia (AWS Center for Quantum Computing): "Ghosts, Necromancy, and Zauner's Conjecture" Abstract | Video
December 8, 2020Chris Heil (Georgia Tech): "Frames, Erasures, and Excess in Infinite Dimensions" Abstract | Video | Slides
December 1, 2020Hartmut Führ (RWTH Aachen): "Frames of translates and the bandwidth intuition" Abstract | Video | Slides
November 17, 2020Philipp Petersen (Universität Wien): "Functions with structured singularities" Abstract | Video
November 10, 2020Alex Cloninger (University of California at San Diego): "Fast Statistical and Geometric Distances Between Families of Distributions" Abstract | Video
November 3, 2020Gerlind Plonka-Hoch (Universität Göttingen): "Optimal Rank-1 Hankel Approximation of Matrices" Abstract | Video | Slides
October 27, 2020Akram Aldroubi (Vanderbilt University): "Transport transforms for data analysis and machine learning" Abstract | Video
October 20, 2020Dustin G. Mixon (The Ohio State University): "Symmetry and optimality in codes" Abstract | Video
October 13, 2020John J. Benedetto (University of Maryland): "Spectral super-resolution and unique extensions for complex measures" Abstract | Video
October 6, 2020Shahaf Nitzan (Georgia Tech): "A few remarks on 'good' exponential Riesz bases" Abstract
September 29, 2020Boris Bukh (Carnegie Mellon University): "Ranks of matrices with few distinct entries" Abstract | Video
September 22, 2020Eric Weber (Iowa State University): "Conjugate Phase Retrieval in Paley-Wiener Space" Abstract | Video | Slides
September 15, 2020Bill Martin (Worcester Polytechnic Institute): "Schoenberg's Theorem and Association Schemes" Abstract | Video | Slides
September 8, 2020Hanmeng (Harmony) Zhan (York University): "DRACKNs and their applications in quantum information" Abstract | Video
September 1, 2020Chris Manon (University of Kentucky): "Spaces of Eigenvalues" Abstract | Video
August 25, 2020Frank Vallentin (Universität zu Köln): "Coloring the Voronoi tessellation of lattices" Abstract | Video
August 18, 2020David Gross (Universität zu Köln): "Representation theory of the Clifford group, with sundry applications" Abstract | Video
August 11, 2020Kasso Okoudjou (Tufts University): "The search for universal minimizers of p-frame potentials" Abstract | Video
August 4, 2020 Marcus Appleby (University of Sydney): "SICs and Number Theory" Abstract | Video
July 28, 2020Matt Fickus (Air Force Institute of Technology): "Mutually Unbiased Equiangular Tight Frames" Abstract | Slides | Video
July 21, 2020Vern Paulsen (University of Waterloo): "Entanglement Breaking Maps and Zauner's Conjecture" Abstract | Video
July 14, 2020Afonso S. Bandeira (ETH Zurich): "Hardness of refuting coloring in random graphs and quiet computational planting" Abstract | Video
July 7, 2020Bernhard Bodmann (University of Houston): "Polynomial embeddings as cheat codes for a real Game of Sloanes" Abstract | Video
June 30, 2020Pete Casazza (University of Missouri): "Two Distance Sets" Abstract | Video
June 23, 2020Alex Iosevich (University of Rochester): "On point configurations and frame theory" Abstract | Video | Slides
June 9, 2020Gene Kopp (University of Bristol): "SIC-POVM existence and the Stark conjectures" Abstract | Video
June 2, 2020Jameson Cahill (New Mexico State University): "Optimal Parseval Frames" Abstract | Video
May 26, 2020Chris Cox (Carnegie Mellon University / Iowa State University): "Nearly Orthogonal Vectors" Abstract | Video
May 19, 2020Hans Parshall (Ohio State University / Western Washington University): "Optimal Line Packings" Abstract | Video