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PRODID:-//Virginia Tech//VT Calendar//EN
BEGIN:VEVENT
DTSTAMP:20200930T190000Z
UID:1601050330220@events.msu.edu
CATEGORIES:Conferences / Seminars / Lectures
DTSTART:20200930T190000Z
DTEND:20200930T195000Z
SUMMARY:Math Seminar Series
DESCRIPTION:
 Combinatorics and Graph Theory\n
 \n
 Josh Hallam 
 from Loyola Marymount University will be speaking.\n
 \n
 The 
 presentation is titled "Whitney 
 Duals of Graded Posets."\n
 \n
 This event takes 
 place online via Zoom.\n
 \n
 The event description 
 is as follows:\n
 \n
 To each graded poset one 
 can associate two sequences of numbers; the 
 Whitney numbers of the first kind and the Whitney 
 numbers of the second kind. One sequence 
 keeps track of the Möbius function at each rank 
 level and the other keeps track of the number 
 of elements at each rank level. The Whitney 
 numbers appear in many contexts in combinatorics. 
 For example, they appear as the coefficients 
 of the chromatic polynomial of a graph 
 and can be used to compute the number of regions 
 in a real hyperplane arrangement. We say 
 that posets P and Q are Whitney duals if the 
 Whitney numbers of the first kind of P are 
 the Whitney numbers of the second kind of Q 
 and vice-versa. In this talk, we will discuss 
 a method to construct Whitney duals using edge 
 labelings and quotient posets. We will also 
 discuss some applications of Whitney duals. 
 This is joint work with Rafael S. González D'León.\n\n
 Price: free\n
 Sponsor: Department of Mathematics\n
 Sponsor's Homepage: https://www.math.msu.edu/\n
 Contact name: Department of Mathematics\n
 Contact phone: (517) 353-0844\n
 for more info visit the web at:\n 
 https://www.math.msu.edu/Seminars/CalendarView.aspx?month-of=September2016\n
LOCATION:Zoom link provided on Math Seminars page
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