activity
20222026
collaborators

8 papers

math.CO2026

The Hypergraph Moore Bound

Afonso S. Bandeira, Dmitriy Kunisky, Petar Nizić-Nikolac +2

The hypergraph Moore bound conjectured by Feige (2008) controls the size of the smallest even cover in a -uniform hypergraph in terms of the average density of hyperedges. An ev…

cs.DS2026

Derandomizing Matrix Concentration Inequalities from Free Probability

Robert Wang, Lap Chi Lau, Hong Zhou

Recently, sharp matrix concentration inequalities~\cite{BBvH23,BvH24} were developed using the theory of free probability. In this work, we design polynomial time deterministic alg…

cs.DS2024

Streaming and Communication Complexity of Load-Balancing via Matching Contractors

Sepehr Assadi, Aaron Bernstein, Zachary Langley +2

In the load-balancing problem, we have an -vertex bipartite graph between a set of clients and servers. The goal is to find an assignment of all clients to the ser…

cs.DS2024

Experimental Design Using Interlacing Polynomials

Lap Chi Lau, Robert Wang, Hong Zhou

We present a unified deterministic approach for experimental design problems using the method of interlacing polynomials. Our framework recovers the best-known approximation guaran…

cs.DS2024

Spectral Sparsification by Deterministic Discrepancy Walk

Lap Chi Lau, Robert Wang, Hong Zhou

Spectral sparsification and discrepancy minimization are two well-studied areas that are closely related. Building on recent connections between these two areas, we generalize the…

cs.DS2023

Fast Algorithms for Directed Graph Partitioning Using Flows and Reweighted Eigenvalues

Lap Chi Lau, Kam Chuen Tung, Robert Wang

We consider a new semidefinite programming relaxation for directed edge expansion, which is obtained by adding triangle inequalities to the reweighted eigenvalue formulation. Apply…

cs.DS2023

Experimental Design for Any -Norm

Lap Chi Lau, Robert Wang, Hong Zhou

We consider a general -norm objective for experimental design problems that captures some well-studied objectives (D/A/E-design) as special cases. We prove that a randomized loc…

cs.DS2022

Cheeger Inequalities for Directed Graphs and Hypergraphs Using Reweighted Eigenvalues

Lap Chi Lau, Kam Chuen Tung, Robert Wang

We derive Cheeger inequalities for directed graphs and hypergraphs using the reweighted eigenvalue approach that was recently developed for vertex expansion in undirected graphs [O…