Local-Minima-Preserving Continuous Relaxation of Ising Problems
Authors: Debraj Banerjee, Santanu Mahapatra, Kunal N. Chaudhury
Organizations: Department of Electrical Engineering, Indian Institute of Science, Bangalore, India · Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore, India
The generalized Ising problem captures a broad spectrum of hard combinatorial problems, including MAX-CUT, Number Partitioning (NPP), and Maximum Independent Set. In this work, we consider the notion of one-flip local minima for this problem. We construct a polynomial relaxation and prove the landscape equivalence theorem: there exists a one-to-one correspondence between the local minima of the relaxation and the one-flip minima of the original Ising problem. This guarantee reduces the Ising problem to finding the local minima of a smooth function, allowing us to leverage gradient-based optimizers such as ADAM. We demonstrate that our method is scalable and it achieves strong performance across challenging benchmarks, including spin-glass models, MAX-CUT, and NPP.