论上图中的回缩、绝对回缩和折叠
On retracts, absolute retracts, and folds in cographs
摘要：
设G和H是两个余图。证明了判定H是否为G的收缩核的问题是NP-完全的。我们表明，这个问题是固定参数听话时，参数的大小H。当仅限于阈值图类或平凡完美图类时，问题在多项式时间内变得容易处理。当一个上图是另一个上图的导出子图时，这个问题也是可解的。我们刻画了上图的绝对收缩。
英文摘要：
Let G and H be two cographs. We show that the problem to determine whether H is a retract of G is NP-complete. We show that this problem is fixed-parameter tractable when parameterized by the size of H. When restricted to the class of threshold graphs or to the class of trivially perfect graphs, the problem becomes tractable in polynomial time. The problem is also soluble when one cograph is given as an induced subgraph of the other. We characterize absolute retracts of cographs.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
