{ "schema_version": "1.0", "title": "Reproduction: On Densest k-Subgraph Mining and Diagonal Loading (Optimization Landscape and Finite-Step Exact Convergence)", "emoji": "🌐", "space_id": "snaykey/repro-sam-saddle", "paper": { "arxiv_id": "2410.07388", "openreview_id": "VQt4w3lElX" }, "tags": [ "icml2026-repro", "paper-VQt4w3lElX" ], "updated_at": "2026-07-29T14:00:00+00:00", "root": { "slug": "index", "title": "Reproduction: On Densest k-Subgraph Mining and Diagonal Loading (Optimization Landscape and Finite-Step Exact Convergence)", "children": [ { "slug": "executive-summary", "title": "Executive summary", "children": [] }, { "slug": "c1-tightness", "title": "Theorem 4 extends the Motzkin-Straus theorem to show the relaxed problem's maximum value equals 1+λ-1/ω, where ω is the largest clique size, establishing that diagonal loading parameter λ≥1 is the minimal value ensuring tightness of the penalty-based relaxation.", "children": [] }, { "slug": "c2-integral-optimum", "title": "Corollary 1 proves that when λ≥1 there always exists a global maximizer of the relaxed objective that is integral, so the relaxed and combinatorial problems share the same optimal value.", "children": [] }, { "slug": "c3-dichotomy", "title": "Lemma 1 shows that for λ>1 there does not exist a non-integral local maximizer, establishing the strict dichotomy that all integral stationary points are local maximizers while non-integral stationary points are strict saddles.", "children": [] }, { "slug": "c4-monotonicity", "title": "Theorem 5 shows that increasing the diagonal loading parameter beyond λ=1 introduces additional spurious local maxima, implying λ=1 optimally trades off relaxation tightness against optimization difficulty.", "children": [] }, { "slug": "c5-sefw", "title": "The saddle-escaping Frank-Wolfe algorithm (Section 3.1) has per-iteration complexity O(m+k log n) and is shown to converge in a finite number of steps to an integral local maximizer of the densest k-subgraph relaxation.", "children": [] }, { "slug": "c6-experiments", "title": "Experiments show the Frank-Wolfe algorithm achieves denser subgraphs than competing methods LRBO, L-ADMM, and EXPP while incurring lower computational cost on real-world graphs with millions of vertices (Section 4).", "children": [] }, { "slug": "conclusion", "title": "Conclusion", "children": [] } ] }, "revision": 1 }