论文标题
在Turán良好的图表上
On Turán-good graphs
论文作者
论文摘要
对于图形$ h $和$ f $，通用的Turán数字$ ex（n，h，f）$是$ n $ vertices上$ f $ fule-free Graph中$ h $的最多副本。我们说，如果$ h $是$ f $-turán-good如果$ ex（n，h，f）$是$（χ（f）-1）$ - PartiteTurán图中的副本数量，前提是$ n $足够大。 如果$ f $具有边缘，我们的删除会降低色数，我们会提出一般定理。特别是，这确定$ ex（n，p_k，c_ {2 \ ell+1}）$和$ ex（n，c_ {2k}，c_ {2 \ ell+1}）$，如果$ n $足够大。当$ f $具有一个顶点时，我们的删除降低了色数时，我们还会研究此案。
For graphs $H$ and $F$, the generalized Turán number $ex(n,H,F)$ is the largest number of copies of $H$ in an $F$-free graph on $n$ vertices. We say that $H$ is $F$-Turán-good if $ex(n,H,F)$ is the number of copies in the $(χ(F)-1)$-partite Turán graph, provided $n$ is large enough. We present a general theorem in case $F$ has an edge whose deletion decreases the chromatic number. In particular, this determines $ex(n,P_k,C_{2\ell+1})$ and $ex(n,C_{2k},C_{2\ell+1})$ exactly, if $n$ is large enough. We also study the case when $F$ has a vertex whose deletion decreases the chromatic number.
