Publications de l'Institut Mathématique, Nouvelle Série Vol. 92(106), pp. 43–51 (2012) 

COMPLEXES OF DIRECTED TREES OF COMPLETE MULTIPARTITE GRAPHSDusko JojicDepartment of Mathematics, University of Banja Luka, Banja Luka, Bosnia and HerzegovinaAbstract: For every directed graph $D$ we consider the complex of all directed subforests $\Delta(D)$. The investigation of these complexes was started by D. Kozlov. We generalize a result of Kozlov and prove that complexes of directed trees of complete multipartite graphs are shellable. We determine the $h$vector of $\Delta(\overrightarrow{K}_{m,n})$ and the homotopy type of $\Delta(\overrightarrow{K}_{n_1,n_2,\ldots,n_k})$. Keywords: shellability; directed trees; multipartite graph Classification (MSC2000): 52B22; 05C20 Full text of the article: (for faster download, first choose a mirror)
Electronic fulltext finalized on: 8 Nov 2012. This page was last modified: 19 Nov 2012.
© 2012 Mathematical Institute of the Serbian Academy of Science and Arts
