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Skew equienergetic digraphs | ||
| Transactions on Combinatorics | ||
| مقاله 2، دوره 5، شماره 1، خرداد 2016، صفحه 15-23 اصل مقاله (226.89 K) | ||
| نوع مقاله: Research Paper | ||
| شناسه دیجیتال (DOI): 10.22108/toc.2016.9372 | ||
| نویسندگان | ||
| Harishchandra S. Ramane* 1؛ K. Channegowda Nandeesh2؛ Ivan Gutman3؛ Xueliang Li4 | ||
| 1Karnatak University, Dharwad, India | ||
| 2Karnatak University, Dharwad | ||
| 3University of Kragujevac, 34000 Kragujevac | ||
| 4Nankai University, Tianjin | ||
| چکیده | ||
| Let $D$ be a digraph with skew-adjacency matrix $S(D)$. The skew energy of $D$ is defined as the sum of the norms of all eigenvalues of $S(D)$. Two digraphs are said to be skew equienergetic if their skew energies are equal. We establish an expression for the characteristic polynomial of the skew adjacency matrix of the join of two digraphs, and for the respective skew energy, and thereby construct non-cospectral, skew equienergetic digraphs on $n$ vertices, for all $n \geq 6$. Thus we arrive at the solution of some open problems proposed in [X. Li, H. Lian, A survey on the skew energy of oriented graphs, arXiv:1304.5707]. | ||
| کلیدواژه‌ها | ||
| energy of graph؛ skew energy؛ skew equienergetic digraphs | ||
| مراجع | ||
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