Title
Linear extensions and order-preserving poset partitions
Abstract
We examine the lattice of all order congruences of a finite poset from the viewpoint of combinatorial algebraic topology. We prove that the order complex of the lattice of all nontrivial order congruences (or order-preserving partitions) of a finite n-element poset P with n ¿ 3 is homotopy equivalent to a wedge of spheres of dimension n - 3 . If P is connected, then the number of spheres is equal to the number of linear extensions of P. In general, the number of spheres is equal to the number of cyclic classes of linear extensions of P.
Year
DOI
Venue
2014
10.1016/j.jcta.2013.09.010
J. Comb. Theory, Ser. A
Keywords
Field
DocType
order complex,order congruence,combinatorial algebraic topology,nontrivial order congruence,linear extension,finite n-element poset p,dimension n-3,order-preserving poset partition,finite poset,cyclic class,homotopy equivalent,homology,poset
Discrete mathematics,Combinatorics,Interval order,Algebraic topology,Lattice (order),Graded poset,Linear extension,Homotopy,Congruence relation,Partially ordered set,Mathematics
Journal
Volume
Issue
ISSN
122
C
0097-3165
Citations 
PageRank 
References 
0
0.34
0
Authors
2
Name
Order
Citations
PageRank
Gejza Jenča13610.14
Peter Sarkoci211312.64