A New Path to Equal-Angle Lines
In the penultimate paragraph, they say, &quot;As a result, the authors were able to prove that when you begin by fixing the angle in advance, the maximum number of equiangular lines is 2d – 2 for one particular angle (approximately 70.7 degrees), and no more than 1.93d for any other angle.&quot;<p>Earlier, they show that in 3 dimensions, you can arrange 6 lines. 2 &gt; 1.93, so I guess either I or they misunderstood something.<p>[Edit] &quot;for…sufficiently large n&quot;<p><a href="https:&#x2F;&#x2F;arxiv.org&#x2F;abs&#x2F;1606.06620" rel="nofollow">https:&#x2F;&#x2F;arxiv.org&#x2F;abs&#x2F;1606.06620</a><p>“in this paper we prove that for every fixed angle θ and sufficiently large n there are at most 2n−2 lines in ℝn with common angle θ”