2017/11/09 by Montgomery, Richard · 7 citations
#05C70 #05C72 #Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.1711.03382
For each r≥ 4, we show that any graph G with minimum degree at least (1-1/100r)|G| has a fractional Kr-decomposition. This improves the best previous bounds on the minimum degree required to guarantee a fractional Kr-decomposition given by Dukes (for small r) and Barber, Kühn, Lo, Montgomery and Osthus (for large r), giving the first bound that is tight up to the constant multiple of r (seen, for example, by considering Turán graphs). In combination with work by Glock, Kühn, Lo, Montgomery and Osthus, this shows that, for any graph F with chromatic number χ(F)≥ 4, and any ε>0, any sufficiently large graph G with minimum degree at least (1-1/100χ(F)+ε)|G| has, subject to some further simple necessary divisibility conditions, an (exact) F-decomposition.