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Sharp Bounds on the Eigenvalues of Kikuchi Graphs and Applications to Quantum Max Cut

3 Pith papers cite this work. Polarity classification is still indexing.

3 Pith papers citing it
abstract

We prove that the maximum eigenvalue of the (both signed and unsigned) Laplacian of level $k$ Kikuchi graph of any graph $G$ with $m$ edges is at most $m+k$. This confirms four recent conjectures of Apte, Parekh, and Sud. As applications, we obtain that tensor products of one and two qubit product states achieve an approximation ratio of $5/8$ for Quantum Max Cut and $5/7$ for the XY Hamiltonian. Moreover, combining our bounds with the algorithms analyzed by Apte, Parekh, and Sud, yields efficient algorithms achieving an approximation ratio of $0.614$ for Quantum Max Cut and $0.674$ for the XY Hamiltonian. Finally, we also make modest progress on Brouwer's conjecture and improve Lew's bound on the sum of the top-$k$ eigenvalues of a Graph Laplacian.

years

2026 3

verdicts

UNVERDICTED 3

representative citing papers

A 0.651-approximation to quantum Max Cut via Rydberg atoms

quant-ph · 2026-06-25 · unverdicted · novelty 7.0

Hybrid Rydberg atom plus SDP algorithm achieves 0.651-approximation for quantum Max Cut, improving on the prior 0.614 SDP-only bound and remaining effective at 89% ground-state fidelity.

On Brouwer's Laplacian conjecture

math.CO · 2026-06-10 · unverdicted · novelty 7.0

Proves Brouwer's Laplacian conjecture and establishes its equivalence to the Grone-Merris-Bai theorem for split graphs.

citing papers explorer

Showing 3 of 3 citing papers.

  • A 0.651-approximation to quantum Max Cut via Rydberg atoms quant-ph · 2026-06-25 · unverdicted · none · ref 16 · internal anchor

    Hybrid Rydberg atom plus SDP algorithm achieves 0.651-approximation for quantum Max Cut, improving on the prior 0.614 SDP-only bound and remaining effective at 89% ground-state fidelity.

  • On Brouwer's Laplacian conjecture math.CO · 2026-06-10 · unverdicted · none · ref 19 · internal anchor

    Proves Brouwer's Laplacian conjecture and establishes its equivalence to the Grone-Merris-Bai theorem for split graphs.

  • Kikuchi Graphs of Random Hypergraphs are Approximately Johnson cs.DS · 2026-06-07 · unverdicted · none · ref 2 · internal anchor

    Level-ℓ Kikuchi graphs of random 2r-uniform hypergraphs spectrally approximate those of the complete hypergraph at near-optimal sampling rates for r ≤ ℓ ≤ n/2.