English
Related papers

Related papers: Escaping the Krylov space during finite precision …

200 papers

We study the Lanczos algorithm where the initial vector is sampled uniformly from $\mathbb{S}^{n-1}$. Let $A$ be an $n \times n$ Hermitian matrix. We show that when run for few iterations, the output of Lanczos on $A$ is almost…

Numerical Analysis · Mathematics 2020-09-15 Jorge Garza-Vargas , Archit Kulkarni

The runtime for Kernel Partial Least Squares (KPLS) to compute the fit is quadratic in the number of examples. However, the necessity of obtaining sensitivity measures as degrees of freedom for model selection or confidence intervals for…

Machine Learning · Statistics 2010-08-13 Nicole Kraemer , Masashi Sugiyama , Mikio Braun

The growing availability and usage of low precision foating point formats has attracts many interests of developing lower or mixed precision algorithms for scientific computing problems. In this paper we investigate the possibility of…

Numerical Analysis · Mathematics 2024-02-14 Haibo Li

We study the statistical properties of Lanczos coefficients over an ensemble of random initial operators generating the Krylov space. We propose two statistical quantities that are important in characterizing the complexity: the average…

Quantum Physics · Physics 2025-03-20 Zhuoran Li , Wei Fan

A thick-restart Lanczos type algorithm is proposed for Hermitian $J$-symmetric matrices. Since Hermitian $J$-symmetric matrices possess doubly degenerate spectra or doubly multiple eigenvalues with a simple relation between the degenerate…

Numerical Analysis · Mathematics 2020-09-14 Ken-Ichi Ishikawa , Tomohiro Sogabe

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…

High Energy Physics - Lattice · Physics 2025-03-24 Ryan Abbott , Daniel C. Hackett , George T. Fleming , Dimitra A. Pefkou , Michael L. Wagman

We propose a new concept of a relatively inexact stochastic subgradient and present novel first-order methods that can use such objects to approximately solve convex optimization problems in relative scale. An important example where…

Optimization and Control · Mathematics 2023-05-30 Yurii Nesterov , Anton Rodomanov

This work introduces a method for determining the energy spectrum of lattice quantum chromodynamics (LQCD) by applying the Lanczos algorithm to the transfer matrix and using a bootstrap generalization of the Cullum-Willoughby method to…

High Energy Physics - Lattice · Physics 2025-05-09 Michael L. Wagman

The low rank approximation of matrices is a crucial component in many data mining applications today. A competitive algorithm for this class of problems is the randomized block Lanczos algorithm - an amalgamation of the traditional block…

Numerical Analysis · Mathematics 2018-08-21 Qiaochu Yuan , Ming Gu , Bo Li

Lanczos-type algorithms are efficient and easy to implement. Unfortunately they breakdown frequently and well before convergence has been achieved. These algorithms are typically based on recurrence relations which involve formal orthogonal…

Numerical Analysis · Mathematics 2015-05-28 Muhammad Farooq , Abdellah Salhi

The need for large-scale electronic structure calculations arises recently in the field of material physics and efficient and accurate algebraic methods for large simultaneous linear equations become greatly important. We investigate the…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 H. Teng , T. Fujiwara , T. Hoshi , T. Sogabe , S. -L. Zhang , S. Yamamoto

We propose a two-sided Lanczos method for the nonlinear eigenvalue problem (NEP). This two-sided approach provides approximations to both the right and left eigenvectors of the eigenvalues of interest. The method implicitly works with…

Numerical Analysis · Mathematics 2016-07-13 Sarah W. Gaaf , Elias Jarlebring

We investigate various aspects of the Lanczos coefficients in a family of free Lifshitz scalar theories, characterized by their integer dynamical exponent, at finite temperature. In this non-relativistic setup, we examine the effects of…

High Energy Physics - Theory · Physics 2024-03-12 M. J. Vasli , K. Babaei Velni , M. R. Mohammadi Mozaffar , A. Mollabashi , M. Alishahiha

Krylov subspace methods are a powerful tool for efficiently solving high-dimensional linear algebra problems. In this work, we study the approximation quality that a Krylov subspace provides for estimating the numerical range of a matrix.…

Numerical Analysis · Mathematics 2024-12-02 Cecilia Chen , John Urschel

In semi-classical systems, the exponential growth of the out-of-timeorder correlator (OTOC) is believed to be the hallmark of quantum chaos. However,on several occasions, it has been argued that, even in integrable systems, OTOC can grow…

Quantum Physics · Physics 2022-06-07 Budhaditya Bhattacharjee , Xiangyu Cao , Pratik Nandy , Tanay Pathak

Several problems in machine learning, statistics, and other fields rely on computing eigenvectors. For large scale problems, the computation of these eigenvectors is typically performed via iterative schemes such as subspace iteration or…

Numerical Analysis · Mathematics 2020-11-03 Vasileios Charisopoulos , Austin R. Benson , Anil Damle

Randomized block Krylov subspace methods form a powerful class of algorithms for computing the extreme eigenvalues of a symmetric matrix or the extreme singular values of a general matrix. The purpose of this paper is to develop new…

Numerical Analysis · Mathematics 2021-10-05 Joel A. Tropp

A deflated restarted Lanczos algorithm is given for both solving symmetric linear equations and computing eigenvalues and eigenvectors. The restarting limits the storage so that finding eigenvectors is practical. Meanwhile, the deflating…

Mathematical Physics · Physics 2014-08-27 Abdou M. Abdel-Rehim , Ronald B. Morgan , Dywayne A. Nicely , Walter Wilcox

This work introduces a novel algorithm to solve large-scale eigenvalue problems and seek a small set of eigenpairs. The method, called randomized Krylov-Schur (rKS), has a simple implementation and benefits from fast and efficient…

Numerical Analysis · Mathematics 2025-08-08 Jean-Guillaume de Damas , Laura Grigori

Models of quantum systems scale exponentially with the addition of single-particle states, which can present computationally intractable problems. Alternatively, quantum computers can store a many-body basis of $2^n$ dimensions on $n$…

Quantum Physics · Physics 2023-09-20 Amanda Bowman