Rounding guarantees for low-dimensional Max-Cut semidefinite relaxations

Given a feasible d-dimensional Max-Cut semidefinite solution strengthened by triangle inequalities, can polynomial-time rounding beat α_GW by 2^−O(d)?

Why it matters and what counts as progress

Why it matters: It asks for a dimension-sensitive improvement over the usual rounding ratio while retaining the stronger relaxation’s constraints.

What counts as progress: A provable improvement above α_GW for every fixed SDP dimension, or sharper dimension dependence under the same triangle inequalities.

How the problem developed

  1. 1995 · Algorithm [1]

    Michel X. Goemans and David P. Williamson Introduced randomized hyperplane rounding with the general Max-Cut guarantee α_GW≈0.87856.

  2. 2005 · Partial result [2]

    Yair Avidor and Uri Zwick Improved rounding guarantees for two- and three-dimensional SDP solutions and posed the fixed higher-dimensional case.

  3. 15 Apr 2026 · Algorithm [3]

    Xiaoyu Chang, Niladri Ghoshal and James R. Lee For every fixed dimension d, gave randomized polynomial-time rounding for feasible d-dimensional Max-Cut SDP solutions with triangle inequalities, improving the Goemans–Williamson factor by 2⁻ᴼ⁽ᵈ⁾.

AI contribution

Sources

  1. Goemans and Williamson, Improved approximation algorithms for maximum cut and satisfiability problems using semidefinite programming
  2. Avidor and Zwick, Approximating MAX CUT with a fixed number of spins
  3. Chang, Ghoshal and Lee, Max Cut with Small-Dimensional SDP Solutions
  4. Max Cut with Small-Dimensional SDP Solutions
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