The optimal-girth conjecture for Wiener-minimizing unicyclic graphs

About 2 years old · traced to

Let D=(d1,d2,…,dt−1,dt,1,…,1)D=(d_1,d_2,\dots,d_{t-1},d_t,1,\dots,1) be a degree sequence with dt≥2d_t\geq 2 and d2≠2d_2\neq 2, and let GG be a unicyclic graph with degree sequence DD. Define

D′=(d1,d2,…,dt−1−1,dt−1,1,…,1)D'=(d_1,d_2,\dots,d_{t-1}-1,d_t-1,1,\dots,1)

and let G(D′)\mathcal{G}(D') be the greedy tree with degree sequence D′D'. If h(G(D′))h(\mathcal{G}(D')) is achieved by a unique leaf, set γ∗=2h(G(D′))−1\gamma^*=2h(\mathcal{G}(D'))-1; otherwise set γ∗=2h(G(D′))\gamma^*=2h(\mathcal{G}(D')). Optimal-girth conjecture. The Wiener index of GG satisfies

W(G)≥min⁡Gu(D,γ∗),C(D,γ∗).W(G)\geq\min\\{\mathcal{G}_u(D,\gamma^*),\mathcal{C}(D,\gamma^*)\\}.

This conjecture proposes that, without fixing the girth, a Wiener-minimizing unicyclic graph is captured by one of the two indicated constructions at the girth determined by the height of the associated greedy tree. The supplied text does not state a resolution, so the conjecture is recorded as open.

References

Primary source

Alewyn P. Burger and Valisoa R. M. Rakotonarivo, “On minimizing the Wiener index of unicyclic graphs with fixed girth and given degree sequence”, arXiv:2410.04903 (2024).

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.