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Upcoming Events

Mar 4

4 Mar (CLIM/GEOL) Jared Nirenberg, Cold Seas in a Warmer Past

Mar 4, 2026, 4:30 - 5:30 PM

Mar 6

Analysis Seminar: Grassmannian codes from stratified frames

Mar 6, 2026, 11:30 AM - 12:30 PM

Mar 6

CAGS: Reciprocal complements: a new construction on integral domains

Mar 6, 2026, 12:30 - 1:30 PM

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Analysis Seminar: Grassmannian codes from stratified frames

Mar 6, 2026, 11:30 AM - 12:30 PM

 

Speaker: Bill Brinkley, Air Force Institute of Technology

Title:  Grassmannian codes from stratified frames

 

Abstract:   An equichordal tight fusion frame (ECTFF) is a finite sequence of equi-dimensional subspaces of a Euclidean space that achieves equality in Conway, Hardin and Sloane’s simplex bound. Every ECTFF is an optimal Grassmannian code with respect to the chordal distance. We introduce a method for constructing an ECTFF from any finite sequence of unit norm tight frames that happen to be “stratified” in a certain sense. We moreover show how to construct stratified unit norm tight frames from a difference family for a finite abelian group,

as well as from a suitable combination of a resolvable balanced incomplete block design and an equiangular tight frame. These results streamline and unify several known constructions that were previously regarded as disparate, and moreover yield infinitely many apparently new ECTFFs.

 

Date/Time: Friday, March 6, 11:30am

Location: Exploratory Hall, Room 4106 or Zoom

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