COLOGNETWENTE
2010
13 years 3 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
13 years 4 months 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
13 years 4 months 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
13 years 4 months 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
13 years 4 months 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
13 years 4 months 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
13 years 4 months 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"...