Dinitz-Garg-Goemans conjecture is false. This graph theory problem was open for ~30 years. The graph below has fractional flow cost 58. Any unsplittable flow (with capacity violation <=15) has cost at least 60. Chat with GPT 5.6 Pro where this was found:
chatgpt.com/share/6a60b2eb-0…Jul 22, 2026 · 12:18 PM UTC 186
662
7,566
2,566,273
I know counterexamples to old conjectures are becoming a meme at this point. But I really cared about this problem and spent many weeks thinking about it a while ago (in both directions, proof and disproof). I think almost all graph flows experts thought about this problem.
12
11
1,536
107,200