Updated characterization conjecture for Turánable oriented graphs

Let HH be an oriented graph. For r1r\geq 1, let FrF_r be the tournament on vertex set [3]r[3]^r in which, for distinct u=(u1,,ur)u=(u_1,\ldots,u_r) and v=(v1,,vr)v=(v_1,\ldots,v_r), the edge is directed from uu to vv when (ui,vi){(1,2),(2,3),(3,1)}(u_i,v_i)\in\{(1,2),(2,3),(3,1)\} for the smallest index ii with uieqviu_i eq v_i. Equivalently, F1=C3F_1=C_3, and Fr+1F_{r+1} consists of three vertex-disjoint copies of FrF_r with all edges directed cyclically between the copies. Let CkC_k^\ell denote the \ell-th power of a consistently oriented cycle on kk vertices.

Updated Turánability conjecture. The oriented graph HH is Turánable if and only if there are integers rr and kk such that

HFrH\subset F_r

and

HC2k+1k.H\subset C_{2k+1}^k.

This conjecture is proposed as an updated characterization after the preceding characterization by containment in some DsD_s was disproved. It is motivated by the tournament case, where containment in both an FrF_r and a C2k+1kC_{2k+1}^k is equivalent to containment in some DsD_s; the source gives no resolution of the updated conjecture.

Sources & referencesView supporting material

Primary source

Igor Araujo and Zimu Xiang, “On the Turánability and tileability of oriented graphs”, arXiv:2507.13267 (2026).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.