Mathematics – Combinatorics
Scientific paper
2008-06-03
Mathematics
Combinatorics
11 pages, 1 figure
Scientific paper
We consider the inversion enumerator I_n(q), which counts labeled trees or, equivalently, parking functions. This polynomial has a natural extension to generalized parking functions. Substituting q = -1 into this generalized polynomial produces the number of permutations with a certain descent set. In the classical case, this result implies the formula I_n(-1) = E_n, the number of alternating permutations. We give a combinatorial proof of these formulas based on the involution principle. We also give a geometric interpretation of these identities in terms of volumes of generalized chain polytopes of ribbon posets. The volume of such a polytope is given by a sum over generalized parking functions, which is similar to an expression for the volume of the parking function polytope of Pitman and Stanley.
Chebikin Denis
Postnikov Alexander
No associations
LandOfFree
Generalized parking functions, descent numbers, and chain polytopes of ribbon posets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Generalized parking functions, descent numbers, and chain polytopes of ribbon posets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Generalized parking functions, descent numbers, and chain polytopes of ribbon posets will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-194852