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SEQUENCE:1
X-APPLE-TRAVEL-ADVISORY-BEHAVIOR:AUTOMATIC
234941
20260417T161029Z
DTSTART;TZID=America/New_York:20260421T140000
DTEND;TZID=America/New_York:2
 0260421T145000
URL;TYPE=URI:https://www.wpi.edu/news/calendar/events/depar
 tment-mathematical-sciences-discrete-math-seminar-ralihe-villagran-wpi-0
Department of Mathematical Sciences Discrete Math Seminar: Ralihe Villagran
 , WPI
\n\n\n      \n      \n\n\n\nTuesday, April 21th, 2026\n2:00pm – 2:50pm\nS
 tratton Hall 311\n\nSpeaker:Ralihe Villagran, WPI\nTitle:On zero-forcing, 
 the minimum rank, and the critical ideals of Block and threshold graphs\nA
 bstract: The zero-forcing number yields a combinatorial lower bound for th
 eminimum rank of a graph. Carlos Alfaro and Jephian Lin studied the relati
 on of both parameters with the algebraic co-rank (cr), which is defined as
  the largest isuch that the i-th critical ideal is trivial. They proved th
 at the min. rank is at most the alg. co-rank for any algebraically closed 
 field, and conjectured that the same was true over the real numbers. We pr
 esent their results on the relationship between these parameters and expan
 d on previously known families where the gaps between them vanish. Finally
 , we study the three parameters for the family of threshold graphs.\n
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