Let G : Gn,p be a binomial random graph with n vertices and edge probability p = p(n), and f be a nonnegative integer-valued function defined on V(G) such that 0 〈 a ≤ f(x) ≤ b 〈 np- 2√nplogn for every E V(G). An fractional f-indicator function is an function h that assigns to each edge of a graph G a number h(e) in [0, 1] so that for each vertex x, we have d^hG(x) = f(x), where dh(x) = ∑ h(e) is the fractional degree xEe ofx inG. Set Eh = {e : e e E(G) and h(e) ≠ 0}. IfGh isaspanningsubgraphofGsuchthat E(Gh) = Eh, then Gh is called an fractional f-factor of G. In this paper, we prove that for any binomial random graph Gn,p 2 with p 〉 n^-2/3, almost surely Gn,p contains an fractional f-factor.
Abstract An f-coloring of a graph G is an edge-coloring of G such that each color appears at each vertex v ∈ V(G) at most f(v) times. The f-core of G is the subgraph of G induced by the vertices v of degree d(v) = f(v)maxv∈y(G){ [d(v)/f(v)l}. In this paper, we find some necessary conditions for a simple graph, whose f-core has maximum degree two, to be of class 2 for f-colorings.
A proper coloring of a graphG is acyclic if G contains no 2-colored cycle.A graph G is acyclically L-list colorable if for a given list assignment L={L(v):v∈V(G)},there exists a proper acyclic coloringφof G such thatφ(v)∈L(v)for all v∈V(G).If G is acyclically L-list colorable for any list assignment L with|L(v)|≥k for all v∈V(G),then G is acyclically k-choosable.In this article,we prove that every toroidal graph is acyclically 8-choosable.