The 1–2–3 Conjecture asserts that, for every connected graph different from K2, its edges can be labeled with 1,2,3 so when coloring each vertex the sum of incident labels, no two adjacent vertices get same color. This conjecture takes place in more general context distinguishing labelings, where goal is to label graphs that some pairs their elements are distinguishable relatively parameter com...

The 1-2-3 Conjecture asks whether almost all graphs can be (edge-)labelled with 1, 2, 3 so that no two adjacent vertices are incident to the same sum of labels. In last decades, several aspects this problem have been studied in literature, including more general versions and slight variations. Notable such variations include List variant, which edges must assigned labels from dedicated lists th...

For a graph G=(V,E) the edge ring k[G] is k[x1,…,xn]/I(G), where n=|V| and I(G) generated by {xixj;{i,j}∈E}. The conjecture we treat following.Conjecture 1. If has 2-linear resolution, then projective dimension of K[G], pd (k[G]), equals maximal degree vertex in G.As far as know, this first mentioned paper Gitler Valencia [7, Conjecture 4.13], there it called Eliahou-Villarreal conjecture. trea...

A new type of decomposition of graphs – the operator decomposition connected with the classical notion of homogeneous set (or module) is introduced. The properties of this decomposition are described. Using this decomposition we prove the following. Let P and Q be two hereditary graph classes such that P is closed with respect to the operation of join and Q is closed with respect to the operati...

A modified k-deck of a graph G is obtained by removing k edges of G in all possible ways, and adding k (not necessarily new) edges in all possible ways. Krasikov and Roditty asked if it was possible to construct the usual k-edge deck of a graph from its modified k-deck. Earlier I solved this problem for the case when k = 1. In this paper, the problem is completely solved for arbitrary k. The pr...

A modified k-deck of a graph is obtained by removing k edges in all possible ways and adding k (not necessarily new) edges in all possible ways. Krasikov and Roditty used these decks to give an independent proof of Müller’s result on the edge reconstructibility of graphs. They asked if a k-edge deck could be constructed from its modified k-deck. In this paper, we solve the problem when k = 1. W...

A linear forest is a in which every connected component path. The arboricity of graph G the minimum number forests covering all edges. In 1980, Akiyama, Exoo, and Harary proposed conjecture, known as Linear Arboricity Conjecture (LAC), stating that Δ-regular has ⌈ Δ + 1 2 ⌉ . 1988, Alon proved LAC holds asymptotically. 1999, list version was raised by An Wu, called List Conjecture. this article...