Hierarchical threshold structure in Max-Cut with geometric edge weights
This study investigates the structure of optimal Max-Cut solutions in complete graphs with geometrically weighted edges, focusing on the parameter regime \(1 < r < 2\). For instances where edge weights decay geometrically in lexicographic order, the authors analyze the optimality transitions within the family of “k-isolated cuts.” By integrating combinatorial optimization, root analysis of polynomials, and extensive numerical verification, they establish—for the first time—a strictly decreasing hierarchy of threshold values \(r_k(n)\) that govern the dominance of these cuts. These thresholds decrease strictly with \(k\) and converge to 1 as \(n \to \infty\). The resulting phase diagram precisely delineates the regions of dominance among competing cuts, and computational evidence for \(n \leq 100\) supports the conjecture that k-isolated cuts are globally optimal for all \(n \geq 7\).