Let G = （V, E） be a simple connected graph, and ｜V（G）｜ ≥ 2. Let f be a mapping from V（G） ∪ E（G） to {1,2…, k}. If arbitary uv ∈ E（G）,f（u） ≠ f（v）,f（u） ≠ f（uv）,f（v） ≠ f（uv）; arbitary uv, uw...Let G = （V, E） be a simple connected graph, and ｜V（G）｜ ≥ 2. Let f be a mapping from V（G） ∪ E（G） to {1,2…, k}. If arbitary uv ∈ E（G）,f（u） ≠ f（v）,f（u） ≠ f（uv）,f（v） ≠ f（uv）; arbitary uv, uw ∈ E（G）（v ≠ w）, f（uv） ≠ f（uw）;arbitary uv ∈ E（G） and u ≠ v, C（u） ≠ C（v）, whereC（u）={f（u）}∪{f（uv）｜uv∈E（G）}.Then f is called a k-adjacent-vertex-distinguishing-proper-total coloring of the graph G（k-AVDTC of G for short）. The number min{k｜k-AVDTC of G} is called the adjacent vertex-distinguishing total chromatic number and denoted by χat（G）. In this paper we prove that if △（G） is at least a particular constant and δ ≥32√△ln△, then χat（G） ≤ △（G） ＋ 10^26 ＋ 2√△ln△.展开更多
An acyclic edge coloring of a graph is a proper edge coloring such that every cycle contains edges of at least three distinct colors. The acyclic chromatic index of a graph G, denoted by a＇（G）, is the minimum numbe...An acyclic edge coloring of a graph is a proper edge coloring such that every cycle contains edges of at least three distinct colors. The acyclic chromatic index of a graph G, denoted by a＇（G）, is the minimum number k such that there is an acyclic edge coloring using k colors. It is known that a＇（G） ≤ 16△ for every graph G where △denotes the maximum degree of G. We prove that a＇（G） 〈 13.8A for an arbitrary graph G. We also reduce the upper bounds of a＇（G） to 9.8△ and 9△ with girth 5 and 7, respectively.展开更多
An r-acyclic edge chromatic number of a graph G,denoted by α＇r（G）,is the minimum number of colors used to produce an edge coloring of the graph such that adjacent edges receive different colors and every cycle C h...An r-acyclic edge chromatic number of a graph G,denoted by α＇r（G）,is the minimum number of colors used to produce an edge coloring of the graph such that adjacent edges receive different colors and every cycle C has at least min {｜C｜,r} colors.We prove that α＇r（G） ≤（4r ＋ 1）△（G）,when the girth of the graph G equals to max{50,△A（G）} and 4 ≤ r ≤ 7.If we relax the restriction of the girth to max {220,A（G）},the upper bound of a＇r（G） is not larger than（2r ＋ 5）△（G） with 4 ≤r≤ 10.展开更多
基金the Natural Science Foundation of Gansu Province （No. 3ZS051-A25-025） the Foundation of Gansu Provincial Department of Education （No. 0501-03）.
文摘Let G = （V, E） be a simple connected graph, and ｜V（G）｜ ≥ 2. Let f be a mapping from V（G） ∪ E（G） to {1,2…, k}. If arbitary uv ∈ E（G）,f（u） ≠ f（v）,f（u） ≠ f（uv）,f（v） ≠ f（uv）; arbitary uv, uw ∈ E（G）（v ≠ w）, f（uv） ≠ f（uw）;arbitary uv ∈ E（G） and u ≠ v, C（u） ≠ C（v）, whereC（u）={f（u）}∪{f（uv）｜uv∈E（G）}.Then f is called a k-adjacent-vertex-distinguishing-proper-total coloring of the graph G（k-AVDTC of G for short）. The number min{k｜k-AVDTC of G} is called the adjacent vertex-distinguishing total chromatic number and denoted by χat（G）. In this paper we prove that if △（G） is at least a particular constant and δ ≥32√△ln△, then χat（G） ≤ △（G） ＋ 10^26 ＋ 2√△ln△.
基金Supported by the National Natural Science Foundation of China(No.11371355)
文摘An acyclic edge coloring of a graph is a proper edge coloring such that every cycle contains edges of at least three distinct colors. The acyclic chromatic index of a graph G, denoted by a＇（G）, is the minimum number k such that there is an acyclic edge coloring using k colors. It is known that a＇（G） ≤ 16△ for every graph G where △denotes the maximum degree of G. We prove that a＇（G） 〈 13.8A for an arbitrary graph G. We also reduce the upper bounds of a＇（G） to 9.8△ and 9△ with girth 5 and 7, respectively.
基金Supported by the National Natural Science Foundation of China(No.11371355)
文摘An r-acyclic edge chromatic number of a graph G,denoted by α＇r（G）,is the minimum number of colors used to produce an edge coloring of the graph such that adjacent edges receive different colors and every cycle C has at least min {｜C｜,r} colors.We prove that α＇r（G） ≤（4r ＋ 1）△（G）,when the girth of the graph G equals to max{50,△A（G）} and 4 ≤ r ≤ 7.If we relax the restriction of the girth to max {220,A（G）},the upper bound of a＇r（G） is not larger than（2r ＋ 5）△（G） with 4 ≤r≤ 10.
