English

Polynomial-Time Algorithms for Weaver's Discrepancy Problem in a Dense Regime

Data Structures and Algorithms 2024-02-14 v1

Abstract

Given v1,,vmCdv_1,\ldots, v_m\in\mathbb{C}^d with vi2=α\|v_i\|^2= \alpha for all i[m]i\in[m] as input and suppose i=1mu,vi2=1\sum_{i=1}^m | \langle u, v_i \rangle |^2 = 1 for every unit vector uCdu\in\mathbb{C}^d, Weaver's discrepancy problem asks for a partition S1,S2S_1, S_2 of [m][m], such that iSju,vi21θ\sum_{i\in S_{j}} |\langle u, v_i \rangle|^2 \leq 1 -\theta for some universal constant θ\theta, every unit vector uCdu\in\mathbb{C}^d and every j{1,2}j\in\{1,2\}. We prove that this problem can be solved deterministically in polynomial time when m49d2m\geq 49 d^2.

Cite

@article{arxiv.2402.08545,
  title  = {Polynomial-Time Algorithms for Weaver's Discrepancy Problem in a Dense Regime},
  author = {Ben Jourdan and Peter Macgregor and He Sun},
  journal= {arXiv preprint arXiv:2402.08545},
  year   = {2024}
}
R2 v1 2026-06-28T14:47:27.936Z