Numerical methods for fractional diffusion

A Bonito, JP Borthagaray, RH Nochetto… - … and Visualization in …, 2018 - Springer
We present three schemes for the numerical approximation of fractional diffusion, which
build on different definitions of such a non-local process. The first method is a PDE approach …

A PDE approach to fractional diffusion in general domains: a priori error analysis

RH Nochetto, E Otárola, AJ Salgado - Foundations of Computational …, 2015 - Springer
The purpose of this work is to study solution techniques for problems involving fractional
powers of symmetric coercive elliptic operators in a bounded domain with Dirichlet boundary …

A PDE approach to space-time fractional parabolic problems

RH Nochetto, E Otárola, AJ Salgado - SIAM Journal on Numerical Analysis, 2016 - SIAM
We study solution techniques for parabolic equations with fractional diffusion and Caputo
fractional time derivative, the latter being discretized and analyzed in a general Hilbert …

A FEM for an optimal control problem of fractional powers of elliptic operators

H Antil, E Otárola - SIAM Journal on Control and Optimization, 2015 - SIAM
We study solution techniques for a linear-quadratic optimal control problem involving
fractional powers of elliptic operators. These fractional operators can be realized as the …

Tensor FEM for spectral fractional diffusion

L Banjai, JM Melenk, RH Nochetto, E Otárola… - Foundations of …, 2019 - Springer
We design and analyze several finite element methods (FEMs) applied to the Caffarelli–
Silvestre extension that localizes the fractional powers of symmetric, coercive, linear elliptic …

A space-time fractional optimal control problem: analysis and discretization

H Antil, E Otarola, AJ Salgado - SIAM Journal on Control and Optimization, 2016 - SIAM
We study a linear-quadratic optimal control problem involving a parabolic equation with
fractional diffusion and Caputo fractional time derivative of orders s∈(0,1) and γ∈(0,1 …

Finite Element Discretizations of a Convective Brinkman–Forchheimer Model Under Singular Forcing

A Allendes, G Campaña, E Otárola - Journal of Scientific Computing, 2024 - Springer
In two-dimensional bounded Lipschitz domains, we analyze a convective Brinkman–
Forchheimer problem on the weighted spaces H 0 1 (ω, Ω)× L 2 (ω, Ω)/R, where ω belongs …

-matrix approximability of inverses of discretizations of the fractional Laplacian

M Karkulik, JM Melenk - Advances in Computational Mathematics, 2019 - Springer
The integral version of the fractional Laplacian on a bounded domain is discretized by a
Galerkin approximation based on piecewise linear functions on a quasiuniform mesh. We …

Multilevel methods for nonuniformly elliptic operators and fractional diffusion

L Chen, R Nochetto, E Otárola, A Salgado - Mathematics of Computation, 2016 - ams.org
We develop and analyze multilevel methods for nonuniformly elliptic operators whose
ellipticity holds in a weighted Sobolev space with an $ A_2 $–Muckenhoupt weight. Using …

Weighted Sobolev Approximation Rates for Neural Networks on Unbounded Domains

A Abdeljawad, T Dittrich - arxiv preprint arxiv:2411.04108, 2024 - arxiv.org
In this work, we consider the approximation capabilities of shallow neural networks in
weighted Sobolev spaces for functions in the spectral Barron space. The existing literature …