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DTSTART:20260308T070000
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DTSTART:20251102T060000
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DTSTART;TZID=America/Toronto:20261030T153000
SEQUENCE:0
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URL:https://uwaterloo.ca/combinatorics-and-optimization/events/tutte-colloq
 uium-bertrand-guenin-integral-set-packing-versus
SUMMARY:Tutte Colloquium | Bertrand Guenin\, Integral Set Packing versus\nI
 ntegral Set Covering
CLASS:PUBLIC
DESCRIPTION:SPEAKER:\n Bertrand Guenin\n\nAFFILIATION:\n University of Wate
 rloo\n\nLOCATION:\n MC 5501\n\nABSTRACT: A 0-1 matrix M is _perfect_ if t
 he polyhedron {x ≥ 0 : Mx\n≤ 1} is integral. Perfect matrices are clos
 ely related to perfect\ngraphs and have several remarkable properties. In 
 particular\,\nperfectness is equivalent to total dual integrality\, and pe
 rfect\nmatrices admit an excluded-minor characterization.\n\nA 0-1 matrix 
 M is _ideal_ if the polyhedron {x ≥ 0 : Mx ≥ 1} is\nintegral. Unlike p
 erfect matrices\, ideal matrices do not correspond to\na single well-under
 stood class of combinatorial objects. In this talk\,\nwe will explore whic
 h of the remarkable properties of perfect matrices\nhave counterparts for 
 ideal matrices. We will discuss what is known\,\nwhat fails\, and some of 
 the intriguing open questions that arise from\nthis comparison.
DTSTAMP:20261024T090559Z
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