比利时vs摩洛哥足彩
,
university of california san diego
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math 269 - combinatorics
christophe hohlweg
york univeristy and fields insititute
realizations of the associahedron and cyclohedron
abstract:
abstract: we describe different realizations with integer coordinates for the associahedron (i.e., the stasheff polytope) and for the cyclohedron (i.e., the bott-taubes polytope), and compare them to the permutahedra of type a and b, respectively. the coordinates are integral and obtained by an algorithm which uses an oriented coxeter graph of type a or b respectively as the only input and which specializes to a procedure presented by j.-l. loday for a certain orientation of the coxeter graph of an. the described realizations have cambrian fans of type a and b as normal fans. this settles a conjecture of n. reading for cambrian fans of these types. this is a joint work with carsten lange
host: jeff remmel
april 25, 2006
4:00 pm
ap&m 7321
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