Results 101 to 110 of about 14,496,760 (259)
Compile‐Once Block Encodings for Masked Similarity‐Transformed Effective Hamiltonians
Composer transforms structured electronic‐structure operators into a reusable quantum‐circuit fabric. Once compiled, the same block‐encoding architecture is re‐dialed through coefficients, rotation angles, and masks to generate similarity‐transformed effective Hamiltonians across related problem instances, avoiding repeated structural recompilation ...
Bo Peng, Yuan Liu, Karol Kowalski
wiley +1 more source
Detecting When One Probe Vector is Enough for Preconditioned Log‐Determinant Approximation
ABSTRACT We present randomized algorithms for estimating the log‐determinant of regularized symmetric positive semi‐definite matrices. The algorithms access the matrix only through matrix vector products, and are based on the introduction of a preconditioner and stochastic trace estimator.
Alice Cortinovis, Daniele Toni
wiley +1 more source
A Class of Preconditioners for Large Indefinite Linear Systems, as by-product of Krylov subspace Methods: Part II [PDF]
In this paper we consider the parameter dependent class of preconditioners M(a,d,D) defined in the companion paper The latter was constructed by using information from a Krylov subspace method, adopted to solve the large symmetric linear system Ax = b ...
Massimo Roma, Giovanni Fasano
core
Fractional calculus and fractional differential equations (FDE) have many applications in different branches of sciences. But, often a real nonlinear FDE has not the exact or analytical solution and must be solved numerically.
Parand K., Nikarya M.
doaj +1 more source
ABSTRACT We derive eigenvalue bounds for symmetric block‐tridiagonal multiple saddle‐point systems preconditioned with block‐diagonal Schur complement matrices. This analysis applies to an arbitrary number of blocks and accounts for the case where the Schur complements are approximated, generalizing the findings in [11, Bergamaschi et al., Linear ...
Marco Pilotto +2 more
wiley +1 more source
GMRES is one of the most powerful and popular methods to solve linear systems in the Krylov subspace; we examine it from two viewpoints: to maximize the decreasing length of the residual vector, and to maintain the orthogonality of the consecutive ...
Chein-Shan Liu +2 more
doaj +1 more source
The Use of Restarted Krylov Methods for Large Sparse Least Squares Problems
ABSTRACT The use of restarted Krylov methods for solving large sparse linear least squares problems suffers from certain inherited difficulties. One of them arises in ill‐conditioned problems, when part of the residual vector is spanned by singular vectors that correspond to small singular values.
Achiya Dax
wiley +1 more source
Two Preconditioners for Time-Harmonic Eddy-Current Optimal Control Problems
In this paper, we consider the numerical solution of a large complex linear system with a saddle-point form obtained by the discretization of the time-harmonic eddy-current optimal control problem.
Xin-Hui Shao, Jian-Rong Dong
doaj +1 more source
Mixed Precision Augmented GMRES
ABSTRACT We aim to accelerate the restarted generalized minimal residual (GMRES) method for the solutions of linear systems by combining two types of techniques. On the one hand, mixed precision GMRES algorithms, which use lower precision in certain steps of the inner cycles, offer significant reductions in computational and memory costs.
Yongseok Jang +2 more
wiley +1 more source
70 years of Krylov subspace methods: The journey continues
E. Carson, J. Liesen, Z. Strakoš
semanticscholar +1 more source

