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SUMMARY:Richard Montgomery (University of Birmingham)
DTSTART:20201005T140000Z
DTEND:20201005T150000Z
DTSTAMP:20260423T052449Z
UID:EPC/31
DESCRIPTION:Title: <a href="https://researchseminars.org/talk/EPC/31/">A s
 olution to Erdős and Hajnal's odd cycle problem</a>\nby Richard Montgomer
 y (University of Birmingham) as part of Extremal and probabilistic combina
 torics webinar\n\n\nAbstract\nI will discuss how to construct cycles of ma
 ny different lengths in graphs\, in particular answering the following two
  problems on odd and even cycles. In 1966\, Erdős and Hajnal asked whethe
 r the sum of the reciprocals of the odd cycle lengths in a graph diverges 
 as the chromatic number increases. Later\, Erdős asked whether there is a
  constant C such that every graph with average degree at least C contains 
 a cycle whose length is a power of 2.\n\nThis is joint work with Hong Liu.
 \n
LOCATION:https://researchseminars.org/talk/EPC/31/
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