Let p,q be two positive integers.The 3-graph F(p,q)is obtained from the complete 3-graph K_(p)^(3)by adding q new vertices and P_(q/2)new edges of the form vxy for which v∈V(K_p~3)and{x,y}are new vertices.It frequent...Let p,q be two positive integers.The 3-graph F(p,q)is obtained from the complete 3-graph K_(p)^(3)by adding q new vertices and P_(q/2)new edges of the form vxy for which v∈V(K_p~3)and{x,y}are new vertices.It frequently appears in many literatures on the Turán number or Turán density of hypergraphs.In this paper,we first construct a new class of r-graphs which can be regarded as a generalization of the 3-graph F(p,q),and prove that these r-graphs have the same Turán density under some situations.Moreover,we investigate the Turán density of the F(p,q)for small p,q and obtain some new bounds on their Turán densities.展开更多
基金the National Natural Science Foundation of China(No.12171089)。
文摘Let p,q be two positive integers.The 3-graph F(p,q)is obtained from the complete 3-graph K_(p)^(3)by adding q new vertices and P_(q/2)new edges of the form vxy for which v∈V(K_p~3)and{x,y}are new vertices.It frequently appears in many literatures on the Turán number or Turán density of hypergraphs.In this paper,we first construct a new class of r-graphs which can be regarded as a generalization of the 3-graph F(p,q),and prove that these r-graphs have the same Turán density under some situations.Moreover,we investigate the Turán density of the F(p,q)for small p,q and obtain some new bounds on their Turán densities.
