Learning optimal multigrid smoothers via neural networks

R Huang, R Li, Y Xi - SIAM Journal on Scientific Computing, 2022 - SIAM
Multigrid methods are one of the most efficient techniques for solving large sparse linear
systems arising from partial differential equations (PDEs) and graph Laplacians from …

Fast deterministic approximation of symmetric indefinite kernel matrices with high dimensional datasets

D Cai, J Nagy, Y Xi - SIAM Journal on Matrix Analysis and Applications, 2022 - SIAM
Kernel methods are used frequently in various applications of machine learning. For large-
scale high dimensional applications, the success of kernel methods hinges on the ability to …

AUTM flow: atomic unrestricted time machine for monotonic normalizing flows

D Cai, Y Ji, H He, Q Ye, Y Xi - Uncertainty in Artificial …, 2022 - proceedings.mlr.press
Nonlinear monotone transformations are used extensively in normalizing flows to construct
invertible triangular mappings from simple distributions to complex ones. In existing …

Data-driven construction of hierarchical matrices with nested bases

D Cai, H Huang, E Chow, Y Xi - SIAM Journal on Scientific Computing, 2024 - SIAM
Hierarchical matrices provide a powerful representation for significantly reducing the
computational complexity associated with dense kernel matrices. For example, the fast …

Accelerating parallel hierarchical matrix-vector products via data-driven sampling

L Erlandson, D Cai, Y Xi, E Chow - 2020 IEEE International …, 2020 - ieeexplore.ieee.org
Hierarchical matrices are scalable matrix representations particularly suited to the case
where the matrix entries are defined by a smooth kernel function evaluated between pairs of …

An adaptive factorized nyström preconditioner for regularized kernel matrices

S Zhao, T Xu, H Huang, E Chow, Y Xi - SIAM Journal on Scientific Computing, 2024 - SIAM
The spectrum of a kernel matrix significantly depends on the parameter values of the kernel
function used to define the kernel matrix. This makes it challenging to design a …

Interpolative decomposition via proxy points for kernel matrices

X Xing, E Chow - SIAM Journal on Matrix Analysis and Applications, 2020 - SIAM
In the construction of rank-structured matrix representations of dense kernel matrices, a
heuristic compression method, called the proxy point method, has been used in practice to …

Data‐driven linear complexity low‐rank approximation of general kernel matrices: A geometric approach

D Cai, E Chow, Y Xi - Numerical Linear Algebra with …, 2023 - Wiley Online Library
A general, rectangular kernel matrix may be defined as K ij= κ (xi, yj) K _ ij= κ\left (x _i, y
_j\right) where κ (x, y) κ\left (x, y\right) is a kernel function and where X= xi i= 1 m X=\left {x …

Physics-informed distribution transformers via molecular dynamics and deep neural networks

D Cai - Journal of Computational Physics, 2022 - Elsevier
Generating quasirandom points with high uniformity is a fundamental task in many fields.
Existing number-theoretic approaches produce evenly distributed points in [0, 1] d in …

Hierarchical adaptive low‐rank format with applications to discretized partial differential equations

S Massei, L Robol, D Kressner - Numerical Linear Algebra with …, 2022 - Wiley Online Library
A novel framework for hierarchical low‐rank matrices is proposed that combines an adaptive
hierarchical partitioning of the matrix with low‐rank approximation. One typical application is …