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COMBINATORICS
2004
93views more  COMBINATORICS 2004»
13 years 7 months ago
Degree Powers in Graphs with Forbidden Subgraphs
For every real p > 0 and simple graph G, set f (p, G) = uV (G) dp (u) , and let (r, p, n) be the maximum of f (p, G) taken over all Kr+1-free graphs G of order n. We prove tha...
Béla Bollobás, Vladimir Nikiforov
JGT
2008
77views more  JGT 2008»
13 years 7 months ago
Graph classes characterized both by forbidden subgraphs and degree sequences
: Given a set F of graphs, a graph G is F-free if G does not contain any member of F as an induced subgraph. We say that F is a degree-sequence-forcing set if, for each graph G in ...
Michael D. Barrus, Mohit Kumbhat, Stephen G. Hartk...
JGT
2010
83views more  JGT 2010»
13 years 5 months ago
Forbidden subgraphs and the existence of a 2-factor
In 1996, Ota and Tokuda showed that a star-free graph with sufficiently high minimum degree admits a 2-factor. More recently it was shown that the minimum degree condition can be ...
Robert E. L. Aldred, Jun Fujisawa, Akira Saito
MFCS
2007
Springer
14 years 1 months ago
NP by Means of Lifts and Shadows
We show that every NP problem is polynomially equivalent to a simple combinatorial problem: the membership problem for a special class of digraphs. These classes are defined by me...
Gábor Kun, Jaroslav Nesetril
IWOCA
2009
Springer
157views Algorithms» more  IWOCA 2009»
14 years 1 months ago
Forbidden Subgraph Colorings and the Oriented Chromatic Number
: We present an improved upper bound of O(d1+ 1 m−1 ) for the (2, F)-subgraph chromatic number χ2,F (G) of any graph G of maximum degree d. Here, m denotes the minimum number of...
N. R. Aravind, C. R. Subramanian