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DTSTART:20240310T070000
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DTSTART:20231105T060000
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DTSTART;TZID=America/Toronto:20240628T153000
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URL:https://uwaterloo.ca/combinatorics-and-optimization/events/tutte-colloq
 uium-jason-gao
SUMMARY:Tutte Colloquium - Jason Gao
CLASS:PUBLIC
DESCRIPTION:TITLE: Graph Embeddings and Map Colorings\n\nSPEAKER:\n Jason 
 Gao\n\nAFFILIATION:\n Carleton University\n\nLOCATION:\n MC 5501\n\nABSTRA
 CT: The famous  Map Color Theorem says that the chromatic\nnumber of a s
 urface of Euler characteristic $c<0$ is equal to\n$\\displaystyle \\left\\
 lfloor\n\\frac{1}{2}\\left(7+\\sqrt{49-24c}\\right)\\right\\rfloor $. This
  was\nproved in 1969 by Ringel and Youngs who showed that $K_n$ can be\nem
 bedded on surfaces of Euler characteristic $c$ such that\n$\\displaystyle 
 n= \\left\\lfloor\n\\frac{1}{2}\\left(7+\\sqrt{49-24c}\\right)\\right\\rfl
 oor $. This leads to\nthe study about the  genus distribution of a graph 
 $G$\, that is\, the\nnumber of embeddings of $G$ on surfaces. This talk wi
 ll go through\nsome recent results about genus distributions of bouquets a
 nd cubic\ngraphs.  Some results and conjectures will also be given about 
 the\ndistribution of the  chromatic number of a random map on a given\nsu
 rface.
DTSTAMP:20260404T152720Z
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