Spectrum conjecture for complete arcs in projective planes

Let PG(2,q)PG(2,q) be the projective plane of order qq, let t2(2,q)\overline{t}_{2}(2,q) be the smallest known size of a complete arc, and let MqM_q be the upper endpoint defined in the source: for even qq, Mq=12(q+4)M_q=\frac{1}{2}(q+4); for odd qq, Mq=12(q+7)M_q=\frac{1}{2}(q+7) in the stated congruence ranges and otherwise Mq=12(q+5)M_q=\frac{1}{2}(q+5). A complete kk-arc is a complete arc with kk points. Spectrum conjecture. Let 353q2879353\le q\le 2879 be an odd prime. Then in PG(2,q)PG(2,q) there are complete kk-arcs of all the sizes in the region

t2(2,q)kMq.\overline{t}_{2}(2,q)\le k\le M_q.

Moreover, complete kk-arcs with

t2(2,q)k12(q+5)\overline{t}_{2}(2,q)\le k\le \frac{1}{2}(q+5)

can be obtained by the randomized greedy algorithms of the cited works with a new approach to creation of starting data. The claim is presented as a computational prediction for the indicated finite range; the supplied text gives no resolution status beyond the source's assertion.

Sources & referencesView supporting material

Primary source

Alexander A. Davydov, Giorgio Faina, Stefano Marcugini and Fernanda Pambianco, “New sizes of complete arcs in PG(2,q)”, arXiv:1004.2817 (2010).

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.