


default search action
SIAM Journal on Numerical Analysis, Volume 58
Volume 58, Number 1, 2020
- Jia Li, Dazhi Zhang
, Xiong Meng
, Boying Wu, Qiang Zhang:
Discontinuous Galerkin Methods for Nonlinear Scalar Conservation Laws: Generalized Local Lax-Friedrichs Numerical Fluxes. 1-20 - Frederic Weidling, Benjamin Sprung, Thorsten Hohage:
Optimal Convergence Rates for Tikhonov Regularization in Besov Spaces. 21-47 - Rafail Z. Dautov, Alexander Lapin
, Shuhua Zhang
:
Error Estimates for Lagrange-Galerkin Approximation of American Options Valuation. 48-65 - Mihály Kovács
, Stig Larsson
, Fardin Saedpanah
:
Mittag-Leffler Euler Integrator for a Stochastic Fractional Order Equation with Additive Noise. 66-85 - Johannes Storn
:
Computation of the LBB Constant for the Stokes Equation with a Least-Squares Finite Element Method. 86-108 - Carsten Carstensen, Qilong Zhai, Ran Zhang:
A Skeletal Finite Element Method Can Compute Lower Eigenvalue Bounds. 109-124 - Xue Hong, Yinhua Xia
:
Arbitrary Lagrangian-Eulerian Discontinuous Galerkin Method for Hyperbolic Equations Involving δ-Singularities. 125-152 - Jérôme Droniou, Robert Eymard:
High-order Mass-lumped Schemes for Nonlinear Degenerate Elliptic Equations. 153-188 - Buyang Li, Kai Wang
, Zhi Zhou
:
Long-time Accurate Symmetrized Implicit-explicit BDF Methods for a Class of Parabolic Equations with Non-self-adjoint Operators. 189-210 - Zhaopeng Hao
, Zhongqiang Zhang
:
Optimal Regularity and Error Estimates of a Spectral Galerkin Method for Fractional Advection-Diffusion-Reaction Equations. 211-233 - Faisal A. Fairag, Johnson D. Audu
:
Two-level Galerkin Mixed Finite Element Method for Darcy-Forchheimer Model in Porous Media. 234-253 - Charles-Edouard Bréhier
, Xu Wang:
On Parareal Algorithms for Semilinear Parabolic Stochastic PDEs. 254-278 - Julian Braun
, Christoph Ortner:
Sharp Uniform Convergence Rate of the Supercell Approximation of a Crystalline Defect. 279-297 - Stefan Müller, Florian Schweiger
, Endre Süli:
Optimal-Order Finite Difference Approximation of Generalized Solutions to the Biharmonic Equation in a Cube. 298-329 - Xiangcheng Zheng, Hong Wang:
An Optimal-Order Numerical Approximation to Variable-order Space-fractional Diffusion Equations on Uniform or Graded Meshes. 330-352 - Ruo Li, Fanyi Yang:
A Sequential Least Squares Method for Poisson Equation Using a Patch Reconstructed Space. 353-374 - Florian Sonner, Thomas Richter
:
Second Order Pressure Estimates for the Crank-Nicolson Discretization of the Incompressible Navier-Stokes Equations. 375-409 - Bosco García-Archilla
, Julia Novo, Edriss S. Titi:
Uniform in Time Error Estimates for a Finite Element Method Applied to a Downscaling Data Assimilation Algorithm for the Navier-Stokes Equations. 410-429 - Buyang Li, Jilu Wang, Liwei Xu
:
A Convergent Linearized Lagrange Finite Element Method for the Magneto-hydrodynamic Equations in Two-Dimensional Nonsmooth and Nonconvex Domains. 430-459 - Andy T. S. Wan, Marc Laforest:
A Posteriori Error Estimation for the p-Curl Problem. 460-491 - Arbaz Khan
, Guido Kanschat:
A Robust A Posteriori Error Estimator for Divergence-Conforming Discontinuous Galerkin Methods for the Oseen Equation. 492-518 - Jean-Luc Guermond
, Bojan Popov
, Jean C. Ragusa
:
Positive and Asymptotic Preserving Approximation of the Radiation Transport Equation. 519-540 - Yuhong Zhang, Li Shan, Yanren Hou
:
Well-Posedness and Finite Element Approximation for the Convection Model in Superposed Fluid and Porous Layers. 541-564 - Victor P. DeCaria
, Traian Iliescu, William J. Layton
, Michael McLaughlin, Michael Schneier:
An Artificial Compression Reduced Order Model. 565-589 - Irene Drelichman
, Ricardo G. Durán, Ignacio Ojea:
A Weighted Setting for the Numerical Approximation of the Poisson Problem with Singular Sources. 590-606 - Jayesh Badwaik
, Adrian Montgomery Ruf
:
Convergence Rates of Monotone Schemes for Conservation Laws with Discontinuous Flux. 607-629 - Ilona Ambartsumyan, Eldar Khattatov
, Jan M. Nordbotten, Ivan Yotov
:
A Multipoint Stress Mixed Finite Element Method for Elasticity on Simplicial Grids. 630-656 - Maria Kazakova, Pascal Noble:
Discrete Transparent Boundary Conditions for the Linearized Green-Naghdi System of Equations. 657-683 - Michael Griebel, Helmut Harbrecht, Michael D. Multerer
:
Multilevel Quadrature for Elliptic Parametric Partial Differential Equations in Case of Polygonal Approximations of Curved Domains. 684-705 - Jay Gopalakrishnan
, Philip L. Lederer
, Joachim Schöberl
:
A Mass Conserving Mixed Stress Formulation for Stokes Flow with Weakly Imposed Stress Symmetry. 706-732 - Habib Ammari, Yat Tin Chow
, Keji Liu:
Optimal Mesh Size for Inverse Medium Scattering Problems. 733-756 - Patrick E. Farrell
, Pablo Alexei Gazca-Orozco
, Endre Süli:
Numerical Analysis of Unsteady Implicitly Constituted Incompressible Fluids: 3-Field Formulation. 757-787 - Claire Evans, Sara N. Pollock
, Leo G. Rebholz, Mengying Xiao:
A Proof That Anderson Acceleration Improves the Convergence Rate in Linearly Converging Fixed-Point Methods (But Not in Those Converging Quadratically). 788-810 - Sören Bartels
, Michael Ruzicka
:
Convergence of Fully Discrete Implicit and Semi-implicit Approximations of Singular Parabolic Equations. 811-833 - Ralf Hiptmair
, Carlos Jerez-Hanckes
, Carolina Urzúa-Torres
:
Optimal Operator Preconditioning for Galerkin Boundary Element Methods on 3-Dimensional Screens. 834-857 - Wei Bian, Xiaojun Chen:
A Smoothing Proximal Gradient Algorithm for Nonsmooth Convex Regression with Cardinality Penalty. 858-883 - Shuonan Wu
, Jinchao Xu:
Simplex-Averaged Finite Element Methods for H(grad), H(curl), and H(div) Convection-Diffusion Problems. 884-906
Volume 58, Number 2, 2020
- Andrea Alessandro Ruggiu
, Jan Nordström
:
Eigenvalue Analysis for Summation-by-Parts Finite Difference Time Discretizations. 907-928 - Martin Hutzenthaler
, Thomas Kruse:
Multilevel Picard Approximations of High-Dimensional Semilinear Parabolic Differential Equations with Gradient-Dependent Nonlinearities. 929-961 - Malgorzata Peszynska
, Ralph E. Showalter
:
Approximation of Scalar Conservation Law with Hysteresis. 962-987 - Meng Chen
, Leevan Ling:
Extrinsic Meshless Collocation Methods for PDEs on Manifolds. 988-1007 - Michel Duprez
, Alexei Lozinski
:
φ-FEM: A Finite Element Method on Domains Defined by Level-Sets. 1008-1028 - Théophile Chaumont-Frelet, Frédéric Valentin:
A Multiscale Hybrid-Mixed Method for the Helmholtz Equation in Heterogeneous Domains. 1029-1067 - Vesa Kaarnioja
, Frances Y. Kuo, Ian H. Sloan
:
Uncertainty Quantification Using Periodic Random Variables. 1068-1091 - Laurent Gosse
, Nicolas Vauchelet
:
A Truly Two-Dimensional, Asymptotic-Preserving Scheme for a Discrete Model of Radiative Transfer. 1092-1116 - Severiano González-Pinto, Ernst Hairer, Domingo Hernández-Abreu
:
Convergence in ℓ2 and ℓ∞ Norm of One-Stage AMF-W-Methods for Parabolic Problems. 1117-1137 - René R. Hiemstra
, Thomas J. R. Hughes
, Carla Manni
, Hendrik Speleers
, Deepesh Toshniwal
:
A Tchebycheffian Extension of Multidegree B-Splines: Algorithmic Computation and Properties. 1138-1163 - Neeraj Sarna, Jan Giesselmann
, Manuel Torrilhon
:
Convergence Analysis of Grad's Hermite Expansion for Linear Kinetic Equations. 1164-1194 - Christopher R. Hoyt, Art B. Owen:
Mean Dimension of Ridge Functions. 1195-1216 - Natalia Kopteva
, Xiangyun Meng:
Error Analysis for a Fractional-Derivative Parabolic Problem on Quasi-Graded Meshes using Barrier Functions. 1217-1238 - Andrew J. Horning
, Alex Townsend
:
FEAST for Differential Eigenvalue Problems. 1239-1262 - Neil K. Chada
, Andrew M. Stuart
, Xin T. Tong
:
Tikhonov Regularization within Ensemble Kalman Inversion. 1263-1294 - Daniel K. Crane, Mark S. Gockenbach, Matthew J. Roberts:
Approximating the Singular Value Expansion of a Compact Operator. 1295-1318 - Kassem Mustapha
:
An L1 Approximation for a Fractional Reaction-Diffusion Equation, a Second-Order Error Analysis over Time-Graded Meshes. 1319-1338 - Chupeng Ma, Liqun Cao, Yanping Lin:
Energy Conserving Galerkin Finite Element Methods for the Maxwell-Klein-Gordon System. 1339-1366 - Shukai Du, Francisco-Javier Sayas:
A Unified Error Analysis of Hybridizable Discontinuous Galerkin Methods for the Static Maxwell Equations. 1367-1391
Volume 58, Number 3, 2020
- James Foster
, Terry J. Lyons, Harald Oberhauser:
An Optimal Polynomial Approximation of Brownian Motion. 1393-1421 - Lin Mu
:
A Uniformly Robust H(DIV) Weak Galerkin Finite Element Methods for Brinkman Problems. 1422-1439 - Wenzhong Zhang, Bo Wang, Wei Cai:
Exponential Convergence for Multipole and Local Expansions and Their Translations for Sources in Layered Media: Two-Dimensional Acoustic Wave. 1440-1468 - Olena Burkovska
, Max D. Gunzburger:
Affine Approximation of Parametrized Kernels and Model Order Reduction for Nonlocal and Fractional Laplace Models. 1469-1494 - Jongho Park
:
Additive Schwarz Methods for Convex Optimization as Gradient Methods. 1495-1530 - Niklas Behringer
, Dmitriy Leykekhman
, Boris Vexler:
Global and Local Pointwise Error Estimates for Finite Element Approximations to the Stokes Problem on Convex Polyhedra. 1531-1555 - Silvia Bertoluzza
, Micol Pennacchio
, Daniele Prada
:
FETI-DP for the Three Dimensional Virtual Element Method. 1556-1591 - Pierre-Henri Maire
, N. Therme:
Weak Consistency of a Staggered Finite Volume Scheme for Lagrangian Hydrodynamics. 1592-1612 - Ruisheng Qi, Xiaojie Wang:
Error Estimates of Semidiscrete and Fully Discrete Finite Element Methods for the Cahn-Hilliard-Cook equation. 1613-1653 - Zhiqiang Cai
, JaEun Ku
:
A Dual Finite Element Method for a Singularly Perturbed Reaction-Diffusion Problem. 1654-1673 - Jie Shen
, Jie Xu:
Unconditionally Bound Preserving and Energy Dissipative Schemes for a Class of Keller-Segel Equations. 1674-1695 - Thomas Apel, Volker Kempf
:
Brezzi-Douglas-Marini Interpolation of Any Order on Anisotropic Triangles and Tetrahedra. 1696-1718 - Bruno Després, Maxime Herda
:
Computation of Sum of Squares Polynomials from Data Points. 1719-1743 - Patrick Henning
, Daniel Peterseim
:
Sobolev Gradient Flow for the Gross-Pitaevskii Eigenvalue Problem: Global Convergence and Computational Efficiency. 1744-1772 - Stefan Kindermann
, Kemal Raik
:
Convergence of Heuristic Parameter Choice Rules for Convex Tikhonov Regularization. 1773-1800 - Evan S. Gawlik
:
High-Order Approximation of Gaussian Curvature with Regge Finite Elements. 1801-1821 - Herbert Egger, Bogdan Radu:
On a Second-Order Multipoint Flux Mixed Finite Element Methods on Hybrid Meshes. 1822-1844 - Daniel Y. Le Roux, Christopher Eldred
, Mark A. Taylor:
Fourier Analyses of High-Order Continuous and Discontinuous Galerkin Methods. 1845-1866 - Mark Ainsworth, Charles Parker
:
H2-Stable Polynomial Liftings on Triangles. 1867-1892 - Chunxiong Zheng, Qiang Du
, Xiang Ma, Jiwei Zhang:
Stability and Error Analysis for a Second-Order Fast Approximation of the Local and Nonlocal Diffusion Equations on the Real Line. 1893-1917 - Changkun Wei
, Jiaqing Yang, Bo Zhang:
Convergence Analysis of the PML Method for Time-Domain Electromagnetic Scattering Problems. 1918-1940 - Malte Winckler, Irwin Yousept
, Jun Zou:
Adaptive Edge Element Approximation for H(curl) Elliptic Variational Inequalities of Second Kind. 1941-1964 - Jérôme Droniou
, Kim-Ngan Le
:
The Gradient Discretization Method for Slow and Fast Diffusion Porous Media Equations. 1965-1992 - Timon S. Gutleb
, Sheehan Olver
:
A Sparse Spectral Method for Volterra Integral Equations Using Orthogonal Polynomials on the Triangle. 1993-2018
Volume 58, Number 4, 2020
- Samuele Rubino
:
Numerical Analysis of a Projection-Based Stabilized POD-ROM for Incompressible Flows. 2019-2058 - Wenwu Gao, Gregory E. Fasshauer
, Xingping Sun, Xuan Zhou:
Optimality and Regularization Properties of Quasi-Interpolation: Deterministic and Stochastic Approaches. 2059-2078 - Jesús María Sanz-Serna, Konstantinos C. Zygalakis
:
Contractivity of Runge-Kutta Methods for Convex Gradient Systems. 2079-2092 - Hugo Leclerc, Quentin Mérigot
, Filippo Santambrogio
, Federico Stra
:
Lagrangian Discretization of Crowd Motion and Linear Diffusion. 2093-2118 - Jens Markus Melenk, Stefan A. Sauter, Céline Torres
:
Wavenumber Explicit Analysis for Galerkin Discretizations of Lossy Helmholtz Problems. 2119-2143 - Jan Glaubitz
:
Stable High Order Quadrature Rules for Scattered Data and General Weight Functions. 2144-2164 - Ernesto Cáceres, Johnny Guzmán, Maxim A. Olshanskii
:
New Stability Estimates for an Unfitted Finite Element Method for Two-Phase Stokes Problem. 2165-2192 - Tomás Gergelits
, Bjørn Fredrik Nielsen, Zdenek Strakos
:
Generalized Spectrum of Second Order Differential Operators. 2193-2211 - Natalia Kopteva
:
Error Analysis for Time-Fractional Semilinear Parabolic Equations Using Upper and Lower Solutions. 2212-2234 - Kiera Kean, Michael Schneier:
Error Analysis of Supremizer Pressure Recovery for POD based Reduced-Order Models of the Time-Dependent Navier-Stokes Equations. 2235-2264 - Davide Pradovera
:
Interpolatory Rational Model Order Reduction of Parametric Problems Lacking Uniform Inf-Sup Stability. 2265-2293 - Hong-lin Liao, Tao Tang, Tao Zhou:
On Energy Stable, Maximum-Principle Preserving, Second-Order BDF Scheme with Variable Steps for the Allen-Cahn Equation. 2294-2314 - Buyang Li
:
Convergence of Dziuk's Linearly Implicit Parametric Finite Element Method for Curve Shortening Flow. 2315-2333 - Erik Burman, Stefan Frei
, Matthew W. Scroggs
:
Weak Imposition of Signorini Boundary Conditions on the Boundary Element Method. 2334-2350 - Jie Yang, Weidong Zhao, Tao Zhou:
A Unified Probabilistic Discretization Scheme for FBSDEs: Stability, Consistency, and Convergence Analysis. 2351-2375 - Christian Meyer, Michael Sievers:
A Priori Error Analysis of Local Incremental Minimization Schemes for Rate-Independent Evolutions. 2376-2403 - Constantin Carle, Marlis Hochbruck, Andreas Sturm:
On Leapfrog-Chebyshev Schemes. 2404-2433
Volume 58, Number 5, 2020
- Changtao Sheng, Jie Shen
, Tao Tang, Li-Lian Wang, Huifang Yuan:
Fast Fourier-like Mapped Chebyshev Spectral-Galerkin Methods for PDEs with Integral Fractional Laplacian in Unbounded Domains. 2435-2464 - Xiaoli Li, Jie Shen
:
Error Analysis of the SAV-MAC Scheme for the Navier-Stokes Equations. 2465-2491 - Xiangcheng Zheng, Hong Wang:
An Error Estimate of a Numerical Approximation to a Hidden-Memory Variable-Order Space-Time Fractional Diffusion Equation. 2492-2514 - Ivan G. Graham
, Euan A. Spence
, Jun Zou:
Domain Decomposition with Local Impedance Conditions for the Helmholtz Equation with Absorption. 2515-2543 - Clément Cancès, Claire Chainais-Hillairet, Maxime Herda
, Stella Krell:
Large Time Behavior of Nonlinear Finite Volume Schemes for Convection-Diffusion Equations. 2544-2571 - Xiu Ye, Shangyou Zhang
:
A Stabilizer Free Weak Galerkin Method for the Biharmonic Equation on Polytopal Meshes. 2572-2588 - Sihong Shao, Yunfeng Xiong:
Branching Random Walk Solutions to the Wigner Equation. 2589-2608 - Irene Kyza
, Stephen Metcalfe:
Pointwise a Posteriori Error Bounds for Blow-Up in the Semilinear Heat Equation. 2609-2631 - Chunmei Wang
, Junping Wang:
A Primal-Dual Weak Galerkin Finite Element Method for Fokker-Planck Type Equations. 2632-2661 - Konstantinos Chrysafinos, Emmanuil H. Georgoulis, Dimitra Plaka:
A Posteriori Error Estimates for the Allen-Cahn Problem. 2662-2683 - Clément Cancès
, Benoît Gaudeul:
A Convergent Entropy Diminishing Finite Volume Scheme for a Cross-Diffusion System. 2684-2710 - Annalisa Buffa
, Riccardo Puppi, Rafael Vázquez Hernández
:
A Minimal Stabilization Procedure for Isogeometric Methods on Trimmed Geometries. 2711-2735 - Buyang Li
, Yuki Ueda
, Guanyu Zhou:
A Second-Order Stabilization Method for Linearizing and Decoupling Nonlinear Parabolic Systems. 2736-2763 - Andrea Bonito, Alan Demlow, Martin W. Licht:
A Divergence-Conforming Finite Element Method for the Surface Stokes Equation. 2764-2798 - Alexander Zaitzeff, Selim Esedoglu, Krishna C. Garikipati:
Variational Extrapolation of Implicit Schemes for General Gradient Flows. 2799-2817 - Jan Nordström
, Thomas M. Hagstrom
:
The Number of Boundary Conditions for Initial Boundary Value Problems. 2818-2828 - Douglas N. Arnold
, Shawn W. Walker
:
The Hellan-Herrmann-Johnson Method with Curved Elements. 2829-2855 - Ani Miraçi
, Jan Papez
, Martin Vohralík:
A Multilevel Algebraic Error Estimator and the Corresponding Iterative Solver with p-Robust Behavior. 2856-2884 - Yuan Xu, Chi-Wang Shu
, Qiang Zhang:
Error Estimate of the Fourth-Order Runge-Kutta Discontinuous Galerkin Methods for Linear Hyperbolic Equations. 2885-2914 - Philip L. Lederer
, Sander Rhebergen
:
A Pressure-Robust Embedded Discontinuous Galerkin Method for the Stokes Problem by Reconstruction Operators. 2915-2933 - Gang Bao, Yiwen Lin, Xiang Xu
:
Inverse Scattering by a Random Periodic Structure. 2934-2952 - Markus Bachmayr, Ivan G. Graham
, Van Kien Nguyen, Robert Scheichl
:
Unified Analysis of Periodization-Based Sampling Methods for Matérn Covariances. 2953-2980 - Martin J. Gander
, Shu-Lin Wu:
A Diagonalization-Based Parareal Algorithm for Dissipative and Wave Propagation Problems. 2981-3009 - Alessia Andò
, Dimitri Breda
:
Convergence Analysis of Collocation Methods for Computing Periodic Solutions of Retarded Functional Differential Equations. 3010-3039 - Junlong Lyu, Zhongjian Wang
, Jack Xin
, Zhiwen Zhang
:
Convergence Analysis of Stochastic Structure-Preserving Schemes for Computing Effective Diffusivity in Random Flows. 3040-3067 - Alexander E. Labovsky:
Approximate Deconvolution with Correction: A Member of a New Class of Models for High Reynolds Number Flows. 3068-3090 - Qiya Hu
, Rongrong Song:
A Novel Least Squares Method for Helmholtz Equations with Large Wave Numbers. 3091-3123
Volume 58, Number 6, 2020
- David F. Anderson
, Chaojie Yuan:
Variance of Finite Difference Methods for Reaction Networks with Non-Lipschitz Rate Functions. 3125-3143 - Michael Feischl
, Daniel Peterseim
:
Sparse Compression of Expected Solution Operators. 3144-3164 - Elisabetta Carlini, Adriano Festa
, Nicolas Forcadel
:
A Semi-Lagrangian Scheme for Hamilton-Jacobi-Bellman Equations on Networks. 3165-3196 - Adi Ditkowski, Sigal Gottlieb
, Zachary J. Grant:
Two-Derivative Error Inhibiting Schemes and Enhanced Error Inhibiting Schemes. 3197-3225 - Kai Wang, Zhi Zhou
:
High-order Time Stepping Schemes for Semilinear Subdiffusion Equations. 3226-3250 - Sarah K. Locke, John R. Singler
:
New Proper Orthogonal Decomposition Approximation Theory for PDE Solution Data. 3251-3285 - Weifeng Qiu, Shun Zhang:
Adaptive First-Order System Least-Squares Finite Element Methods for Second-Order Elliptic Equations in Nondivergence Form. 3286-3308 - Ricardo G. Durán, Lucia Gastaldi
, Ariel L. Lombardi
:
Analysis of Finite Element Approximations of Stokes Equations with NonSmooth Data. 3309-3331 - Sören Bartels
:
Numerical Simulation of Inextensible Elastic Ribbons. 3332-3354 - Albert Cohen, Wolfgang Dahmen, Ronald A. DeVore, Jalal Fadili, Olga Mula
, James A. Nichols
:
Optimal Reduced Model Algorithms for Data-Based State Estimation. 3355-3381 - Hendrik Ranocha
, David I. Ketcheson
:
Energy Stability of Explicit Runge-Kutta Methods for Nonautonomous or Nonlinear Problems. 3382-3405 - Ignacio Muga, Kristoffer G. van der Zee
:
Discretization of Linear Problems in Banach Spaces: Residual Minimization, Nonlinear Petrov-Galerkin, and Monotone Mixed Methods. 3406-3426 - Paul Manns
, Christian Kirches
:
MultiDimensional Sum-Up Rounding for Elliptic Control Systems. 3427-3447 - Sergio Amat, Juan Ruiz
, Chi-Wang Shu
, Dionisio F. Yáñez
:
A New WENO-2r Algorithm with Progressive Order of Accuracy Close to Discontinuities. 3448-3474 - Georgios Akrivis, Emmanuil Katsoprinakis:
An analogue to the A(θ)-stability concept for implicit-explicit BDF methods. 3475-3503 - Sabrina Guastavino
, Federico Benvenuto
:
Convergence Rates of Spectral Regularization Methods: A Comparison between Ill-Posed Inverse Problems and Statistical Kernel Learning. 3504-3529 - Ting Sun, Jilu Wang, Chunxiong Zheng:
Fast Evaluation of Artificial Boundary Conditions for Advection Diffusion Equations. 3530-3557

manage site settings
To protect your privacy, all features that rely on external API calls from your browser are turned off by default. You need to opt-in for them to become active. All settings here will be stored as cookies with your web browser. For more information see our F.A.Q.