Abstract
As of October 30, 2026, the Einstein Arena’s leader on the first autocorrelation constant C1 stands at 1.5027434867, and MILO’s evolved agent harnesses report 1.5027435984. Under a two-hour, four-thread budget, Claude Opus 5.5 surpasses none of the Endless Exam’s 30 published frontiers. In the published optima of these minimax problems, the maximum is attained, to within the venue’s minimum improvement, at thousands of points, or the circles sit at a KKT point. Any improvement larger than that minimum must lower the value at every one of these points at once. Active-set escape, which we introduce, is a search in which each move changes the near-active set and a global re-melt and a second-order solve finish the new basin. We gave Claude Opus 5.5 agents hours of autonomous work and an exact evaluator, and they wrote these moves themselves. Three agents sharing an archive of verified attempts, with no weight update, certify C1 ≤ 1.50266484… after 40.75 working hours. The bound lies 7,865 times the Arena’s minimum improvement below its leader. A single agent with no outer loop also passes the leader, by 7,200 times the minimum improvement. The same moves lower the signed autocorrelation constant below MILO’s value and set the best sum of radii for unequal circles in a square at 306 Packomania sizes up to N = 10,000. A preregistered classical optimizer started from the same constructions stalls after gains about three thousand times smaller. Witnesses and exact verifiers ship with the paper.
Code and data
Ancillary files: witnesses, exact verifiers and hashes
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Cite
@misc{cumes2026new,
title = {{A New Upper Bound for the First Autocorrelation Inequality and 306 Circle-Packing Records via Active-Set Escape from Equioscillating and KKT Optima}},
author = {Cumes, Lindell S.},
year = {2026},
url = {https://qwntl.com/paper-new-constructions}
}