Italo J. Dejter1
1University of Puerto Rico Rio Piedras, PR 00936-8377
Abstract:

Let \( 0<k\in\mathbb{Z} \). Let the star 2-set transposition graph \( ST^2_k \) be the \( (2k-1) \)-regular graph whose vertices are the \( 2k \)-strings on \( k \) symbols, each symbol repeated twice, with its edges given each by the transposition of the initial entry of one such \( 2k \)-string with any entry that contains a different symbol than that of the initial entry. The pancake 2-set transposition graph \( PC^2_k \) has the same vertex set of \( ST^2_k \) and its edges involving each the maximal product of concentric disjoint transpositions in any prefix of an endvertex string, including the external transposition being that of an edge of \( ST^2_k \). For \( 1<k\in\mathbb{Z} \), we show that \( ST^2_k \) and \( PC^2_k \), among other intermediate transposition graphs, have total colorings via \( 2k-1 \) colors. They, in turn, yield efficient dominating sets, or E-sets, of the vertex sets of \( ST^2_k \) and \( PC^2_k \), and partitions into \( 2k-1 \) such E-sets, generalizing Dejter-Serra work on E-sets in such graphs.

Zhuang Xiong1, Yaoping Hou1
1College of Mathematics and Statistics, Hunan Normal University, small Changsha, Hunan 410081, China
Abstract:

This paper investigates the Tur{\’a}n-like problem for \(\mathcal{K}^-_{r + 1}\)-free \((r \geq 2)\) unbalanced signed graphs, where \(\mathcal{K}^-_{r + 1}\) is the set of unbalanced signed complete graphs with \(r+1\) vertices. The maximum number of edges and the maximum index for \(\mathcal{K}^-_{r + 1}\)-free unbalanced signed graphs are given. Moreover, the extremal \(\mathcal{K}^-_{r + 1}\)-free unbalanced signed graphs with the maximum index are characterized.

Winfried Hochstättler1, Mehrdad Nasernejad2
1Fern Universität in Hagen, Fakultät für Mathematik und Informatik, 58084 Hagen, Germany
2Univ. Artois, UR 2462, Laboratoire de Mathématique de Lens (LML), F-62300 Lens, France
Abstract:

In this paper, we give a classification of all Mengerian \(4\)-uniform hypergraphs derived from graphs.

Huifeng Zhang1,2, Jun Zhu2, Xirong Xu2, Peng Zhang3
1Zhejiang Lab, Hangzhou,311100,China
2School of Computer Science and Technology Dalian University of Technology, Dalian, 116024, China
3Department of Computer Science Zhongshan College of Dalian Medical University, Dalian, 116085, China
Abstract:

The \( n \)-dimensional Möbius cube \( MQ_n \) is an important variant of the hypercube \( Q_n \), which possesses some properties superior to the hypercube. This paper investigates the fault-tolerant edge-pancyclicity of \( MQ_n \), and shows that if \( MQ_n \) (\( n \geq 5 \)) contains at most \( n-2 \) faulty vertices and/or edges then, for any fault-free edge \( uv \) in \( MQ_n^i (i=0,1) \) and any integer \( \ell \) with \( 7-i \leqslant \ell \leqslant 2^n – f_v \), there is a fault-free cycle of length \( \ell \) containing the edge \( uv \), where \( f_v \) is the number of faulty vertices. The result is optimal in some senses.

Andrea Lucchini1
1Università degli Studi di Padova Dipartimento di Matematica “Tullio Levi-Civita” Via Trieste 63, 35121 Padova, Italy
Abstract:

In a recent paper Cameron, Lakshmanan and Ajith [6] began an exploration of hypergraphs defined on algebraic structures, especially groups, to investigate whether this can add a new perspective. Following their suggestions, we consider suitable hypergraphs encoding the generating properties of a finite group. In particular, answering a question asked in their paper, we classified the finite solvable groups whose generating hypergraph is the basis hypergraph of a matroid.

Huixian Li1, Guang Li1, Shengjin Ji1
1School of Mathematics and Statistics Shandong University of Technology, Zibo, China
Abstract:

Let \( G \) be a graph, the zero forcing number \( Z(G) \) is the minimum of \( |Z| \) over all zero forcing sets \( Z \subseteq V(G) \). In this paper, we are interested in studying the zero forcing number of quartic circulant graphs \( C_{p}\left(s,t\right) \), where \( p \) is an odd prime. Based on the fact that \( C_{p}\left(s,t\right) \cong C_{p}\left(1,q\right) \), we give the exact values of the zero forcing number of some specific quartic circulant graphs.

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