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Stability of graphs.

Demir, Bünyamin, Deniz, Ali, Koçak, Sahin (2009)

The Electronic Journal of Combinatorics [electronic only]

Stable graphs

Klaus-Peter Podewski, Martin Ziegler (1978)

Fundamenta Mathematicae

Stable rational cohomology of automorphism groups of free groups and the integral cohomology of moduli spaces of graphs.

Craig A. Jensen (2002)

Publicacions Matemàtiques

It is not known whether or not the stable rational cohomology groups H*(Aut(F∞);Q) always vanish (see Hatcher in [5] and Hatcher and Vogtmann in [7] where they pose the question and show that it does vanish in the first 6 dimensions). We show that either the rational cohomology does not vanish in certain dimensions, or the integral cohomology of a moduli space of pointed graphs does not stabilize in certain other dimensions. Similar results are stated for groups of outer automorphisms. This yields...

Stable sets for ( P , K 2 , 3 ) -free graphs

Raffaele Mosca (2012)

Discussiones Mathematicae Graph Theory

The Maximum Stable Set (MS) problem is a well known NP-hard problem. However different graph classes for which MS can be efficiently solved have been detected and the augmenting graph technique seems to be a fruitful tool to this aim. In this paper we apply a recent characterization of minimal augmenting graphs [22] to prove that MS can be solved for ( P , K 2 , 3 ) -free graphs in polynomial time, extending some known results.

Standard monomials for q-uniform families and a conjecture of Babai and Frankl

Gábor Hegedűs, Lajos Rónyai (2003)

Open Mathematics

Let n, k, α be integers, n, α>0, p be a prime and q=p α. Consider the complete q-uniform family k , q = K n : K k ( m o d q ) We study certain inclusion matrices attached to F(k,q) over the field 𝔽 p . We show that if l≤q−1 and 2l≤n then r a n k 𝔽 p I ( ( k , q ) , n ) n This extends a theorem of Frankl [7] obtained for the case α=1. In the proof we use arguments involving Gröbner bases, standard monomials and reduction. As an application, we solve a problem of Babai and Frankl related to the size of some L-intersecting families modulo q.

Star Coloring of Subcubic Graphs

T. Karthick, C.R. Subramanian (2013)

Discussiones Mathematicae Graph Theory

A star coloring of an undirected graph G is a coloring of the vertices of G such that (i) no two adjacent vertices receive the same color, and (ii) no path on 4 vertices is bi-colored. The star chromatic number of G, χs(G), is the minimum number of colors needed to star color G. In this paper, we show that if a graph G is either non-regular subcubic or cubic with girth at least 6, then χs(G) ≤ 6, and the bound can be realized in linear time.

Star number and star arboricity of a complete multigraph

Chiang Lin, Tay-Woei Shyu (2006)

Czechoslovak Mathematical Journal

Let G be a multigraph. The star number s ( G ) of G is the minimum number of stars needed to decompose the edges of G . The star arboricity s a ( G ) of G is the minimum number of star forests needed to decompose the edges of G . As usual λ K n denote the λ -fold complete graph on n vertices (i.e., the multigraph on n vertices such that there are λ edges between every pair of vertices). In this paper, we prove that for n 2 ...

Star-Cycle Factors of Graphs

Yoshimi Egawa, Mikio Kano, Zheng Yan (2014)

Discussiones Mathematicae Graph Theory

A spanning subgraph F of a graph G is called a star-cycle factor of G if each component of F is a star or cycle. Let G be a graph and f : V (G) → {1, 2, 3, . . .} be a function. Let W = {v ∈ V (G) : f(v) = 1}. Under this notation, it was proved by Berge and Las Vergnas that G has a star-cycle factor F with the property that (i) if a component D of F is a star with center v, then degF (v) ≤ f(v), and (ii) if a component D of F is a cycle, then V (D) ⊆ W if and only if iso(G − S) ≤ Σx∈S f(x) for all...

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