ACMD Seminar: From Graph Decomposition to Matrix Apportionment and Back

Edinah Gnang
Assistant Professor, Dept. of Applied Mathematics & Statistics, Johns Hopkins University

Thursday, Oct. 24, 2024, 3:00-4:00 PM ET (1:00-2:00 PM MT)

Abstract: There has been extensive study of diagonalization of matrices. Diagonalization can be viewed as using a similarity transform to concentrate the magnitude of all entries within as small a subset of entries as possible. We motivate and present results Matrix apportionment which can be viewed as reversing this process, namely spreading out the magnitudes of entries as uniformly as possible. Matrix apportionment has connections to classical problems of combinatorics, including graph decomposition, as well as connections with the new study of instantaneous uniform mixing in quantum walks. This talk is based on joint work with Antwan Clark, Bryan A. Curtis, and Leslie Hogben.

Bio: Edinah Gnang is an assistant professor of applied mathematics and statistics. His research interests include discrete mathematics, graph theory, multilinear algebra, and experimental math. Gnang’s most recent work focuses on functional graph theory. Gnang earned his B.S. degree in mathematics and physics from the University of Montreal in 2005 and his Ph.D. in computer science from Rutgers University in 2013. From 2013 to 2014, he held a joint postdoctorate position at the Institute for Advanced Study and the Princeton University Center for Computational Intractability. He joined Johns Hopkins in 2017 after spending three years at Purdue University as a Golomb Visiting Assistant Professor of Mathematics.

Host: Anthony Kearsley

Note: This talk will be recorded to provide access to NIST staff and associates who could not be present to the time of the seminar. The recording will be made available in the Math channel on NISTube, which is accessible only on the NIST internal network. This recording could be released to the public through a Freedom of Information Act (FOIA) request. Do not discuss or visually present any sensitive (CUI/PII/BII) material. Ensure that no inappropriate material or any minors are contained within the background of any recording. (To facilitate this, we request that cameras of attendees are muted except when asking questions.)

*Safety Precaution: The hallway leading from the Courtyard to the exit closest to B-111 and B-113 will be used by contractors to move debris, machinery, and other supplies, as well as will be heavily trafficked by the contractors throughout the process. Be aware of the safety precautions posted during this time.

Note: Visitors from outside NIST must contact Meliza Lane at least 24 hours in advance.