Optimal acyclic edge colouring of grid like graphs
نویسندگان
چکیده
منابع مشابه
Acyclic edge-colouring of planar graphs∗
A proper edge-colouring with the property that every cycle contains edges of at least three distinct colours is called an acyclic edge-colouring. The acyclic chromatic index of a graph G, denoted χa(G), is the minimum k such that G admits an acyclic edge-colouring with k colours. We conjecture that if G is planar and ∆(G) is large enough then χa(G) = ∆(G). We settle this conjecture for planar g...
متن کاملAcyclic edge colouring of plane graphs
A proper edge-colouring with the property that every cycle contains edges of at least three distinct colours is called an acyclic edge-colouring. The acyclic chromatic index of a graph G, denoted χa(G), is the minimum k such that G admits an acyclic edge-colouring with k colours. We conjecture that if G is planar and ∆(G) is large enough then χa(G) = ∆(G). We settle this conjecture for planar g...
متن کاملAcyclic colouring of graphs
A vertex colouring of a graph G is called acyclic if no two adjacent vertices have the same colour and there is no two-coloured cycle in G. The acyclic chromatic number of G, denoted by A(G), is the least number of colours in an acyclic colouring of G. We show that if G has maximum degree d then A(G) = O(d 4 3 ) as d → ∞. This settles a problem of Erdős who conjectured, in 1976, that A(G) = o(d...
متن کاملOn Acyclic Edge Colouring of Outerplanar Graphs etc
An acyclic edge colouring of a graph is a proper edge colouring having no 2-coloured cycle, that is, a colouring in which the union of any two colour classes forms a linear forest. The acyclic chromatic index of a graph is the minimum number k such that there is an acyclic edge colouring using k colours and is usually denoted by a′(G). Determining a ′(G) exactly is a very hard problem (both the...
متن کاملAcyclic edge colouring of planar graphs without short cycles
A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G. The acyclic edge chromatic number of G is the least number of colors in an acyclic edge coloring of G. In this paper, it is proved that the acyclic edge chromatic number of a planar graph G is at most ∆(G)+2 if G contains no i-cycles, 4≤ i≤ 8, or any two 3-cycles are not incident with a common vertex and ...
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ژورنال
عنوان ژورنال: Discrete Mathematics
سال: 2010
ISSN: 0012-365X
DOI: 10.1016/j.disc.2010.05.033