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