COLOGNETWENTE
2010
13 years 11 months ago
2010
In this paper we analyze O’Hara’s partition bijection. We present three type of results. First, we show that O’Hara’s bijection can be viewed geometrically as a certain sci...
DM
1999
14 years 3 days ago
1999
If : L L is a bijection from the set of lines of a linear space (P, L) onto the set of lines of a linear space (P , L ) (dim (P, L), dim (P , L ) 3), such that intersecting lin...
DAM
1998
14 years 3 days ago
1998
We give a simple and natural proof of (an extension of) the identity P(k, l, n) = P2(k − 1, l − 1, n − 1). The number P(k, l, n) counts noncrossing partitions of {1, 2, . . ...
COMBINATORICS
2004
14 years 9 days ago
2004
We extend Schaeffer's bijection between rooted quadrangulations and welllabeled trees to the general case of Eulerian planar maps with prescribed face valences to obtain a bi...
JCT
2006
14 years 12 days ago
2006
We define a bijection that transforms an alternating sign matrix A with one -1 into a pair (N, E) where N is a (so called) neutral alternating sign matrix (with one -1) and E is an...
COMBINATORICS
2007
14 years 13 days ago
2007
The known bijections on Dyck paths are either involutions or have notoriously intractable cycle structure. Here we present a size-preserving bijection on Dyck paths whose cycle st...
EJC
2010
14 years 15 days ago
2010
This article presents new bijections on planar maps. At first a bijection is established between bipolar orientations on planar maps and specific "transversal structures"...