Pith. sign in

REVIEW 5 cited by

Filtered Rayleigh-Ritz is all you need

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 2503.17357 v1 pith:KCGFSXAF submitted 2025-03-21 hep-lat cs.NAmath.NA

Filtered Rayleigh-Ritz is all you need

classification hep-lat cs.NAmath.NA
keywords lanczosblockmethodsrayleigh-ritzalgorithmallowscorrelationeigenvalue
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
0 comments
Share X Bluesky LinkedIn Reddit HN
read the original abstract

Recent work has shown that the (block) Lanczos algorithm can be used to extract approximate energy spectra and matrix elements from (matrices of) correlation functions in quantum field theory, and identified exact coincidences between Lanczos analysis methods and others. In this work, we note another coincidence: the Lanczos algorithm is equivalent to the well-known Rayleigh-Ritz method applied to Krylov subspaces. Rayleigh-Ritz provides optimal eigenvalue approximations within subspaces; we find that spurious-state filtering allows these optimality guarantees to be retained in the presence of statistical noise. We explore the relation between Lanczos and Prony's method, their block generalizations, generalized pencil of functions (GPOF), and methods based on the generalized eigenvalue problem (GEVP), and find they all fall into a larger "Prony-Ritz equivalence class", identified as all methods which solve a finite-dimensional spectrum exactly given sufficient correlation function (matrix) data. This equivalence allows simpler and more numerically stable implementations of (block) Lanczos analyses.

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 5 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Lattice evidence that scalar glueballs are small

    hep-lat 2025-08 conditional novelty 8.0

    First lattice extraction of scalar glueball gravitational form factors gives a mass radius of 0.263(31) fm, smaller than typical hadrons.

  2. First constraints on the nonperturbative gluon Collins-Soper kernel

    hep-lat 2026-07 conditional novelty 7.0

    First lattice-QCD constraints on the nonperturbative gluon Collins-Soper kernel are obtained at near-physical pion mass with uNNLL LaMET matching on a single a=0.15 fm ensemble.

  3. The Causal Bootstrap: Bounding Smeared Spectral Functions from Non-Perturbative Euclidean Data

    hep-lat 2026-05 unverdicted novelty 7.0

    The causal bootstrap computes rigorous bounds on smeared spectral functions from non-perturbative Euclidean data by optimizing over the convex set of compatible positive spectral densities and reducing dual problems t...

  4. Unbiased Krylov subspace method for the extraction of ground state from lattice correlators

    hep-lat 2025-11 unverdicted novelty 6.0

    SVD low-rank approximation plus variance extrapolation removes bias from Krylov subspace ground-state extraction in lattice correlators.

  5. Unbiased Krylov subspace method for the extraction of ground state from lattice correlators

    hep-lat 2025-11 conditional novelty 6.0

    A low-rank SVD-truncated transfer-matrix GEVP with extrapolation in the eigenvalue variance recovers ground-state energies and matrix elements from noisy lattice correlators without assuming ground-state dominance.