# Ragnar Winther

External collaborator

## Publications

Simula-affiliated publications listed

### 2017

#### Journal Articles

J. Lee, K. Mardal and R. Winther

Parameter-robust discretization and preconditioning of Biot's consolidation model

SIAM Journal of Scientific Computing

### 2015

#### Book Chapters

A. Tveito, H. P. Langtangen and R. Winther

Computational Partial Differential Equations

Encyclopedia of Applied and Computational Mathematics

### 2013

#### Journal Articles

K. Mardal, J. Schoberl and R. Winther

A Uniformly Stable Fortin Operator for the Taylor-Hood Element

Numerische Mathematik

### 2012

#### Technical reports

K. Mardal, J. Schoberl and R. Winther

A Uniform Inf-Sup Condition With Applications to Preconditioning

### 2011

#### Journal Articles

K. Mardal and R. Winther

Preconditioning Discretizations of Systems of Partial Differential Equations

Numerical Linear Algebra with Applications

#### Book Chapters

K. Mardal and R. Winther

Construction of Preconditioners by Mapping Properties for Systems of Partial Differential Equations

Efficient preconditioning methods for elliptic partial differential equations

### 2010

#### Journal Articles

M. E. Rognes and R. Winther

Mixed Finite Element Methods for Viscoelasticity With Weak Symmetry

Mathematical Models and Methods in Applied Sciences (M3AS)

### 2009

#### Journal Articles

T. K. Karper, K. Mardal and R. Winther

Unified Finite Element Discretizations of Coupled Darcy-Stokes Flow

Numerical Methods for Partial Differential Equations

#### Books

A. Tveito and R. Winther

Introduction to Partial Differential Equations; a Computational Approach

### 2006

#### Journal Articles

K. Mardal and R. Winther

An Observation on Korn's Inequality for Nonconforming Finite Element Methods

Math. Comp.

### 2004

#### Journal Articles

K. Mardal and R. Winther

Uniform Preconditioners for the Time Dependent Stokes Problem

Numerische Mathematik

### 2002

#### Journal Articles

K. Mardal, X. Tai and R. Winther

A Robust Finite Element Method for Darcy-Stokes Flow

SIAM Journal on Numerical Analysis

H. P. Langtangen, K. Mardal and R. Winther

Numerical Methods for Incompressible Viscous Flow

Advances in Water Resources

T. Lyche, T. K. Nilssen and R. Winther

Preconditioned Iterative Methods for Scattered Data Interpolation

Advances in Computational Mathematics

#### Books

A. Tveito and R. Winther

Einführung in Die Theorie Der Partiellen Differentialgleichungen; Ein Numerischer Zugang

### 2001

#### Journal Articles

T. K. Nilssen, X. Tai and R. Winther

A Robust Nonconforming H2-Element

Mathematics of Computation

### 2000

#### Talks, contributed

T. K. Nilssen and R. Winther

Preconditioned Iterative Methods for Scattered Data Interpolation

Talk at the Mathematical Methods for Curves and Surfaces, Oslo, Norway

### 1999

#### Journal Articles

W. Shen, A. Tveito and R. Winther

On the Zero Relaxation Limit for a System Modeling the Motions of a Viscoelastic Solid

Siam J. of Math. Anal.

### 1998

#### Proceedings, refereed

W. Shen, A. Tveito and R. Winther

Rate of Convergence for the Zero Relaxation Limit

Proceedings of the seventh international conference on hyperbolic problems

### 1997

#### Journal Articles

H. J. Schroll, A. Tveito and R. Winther

An L^1-Error Bound for a Finite Difference Scheme Applied to a Stiff System of Conservation Laws

SIAM J. Numer. Anal.

A. Tveito and R. Winther

On the Rate of Convergence to Equilibrium for a System of Conservation Laws Including a Relaxation Term

SIAM Journal on Mathematical Analysis

### 1996

#### Journal Articles

W. Shen, A. Tveito and R. Winther

A System of Conservation Laws Including a Stiff Relaxation Term; the 2D Case

BIT

J. O. Langseth, A. Tveito and R. Winther

On the Convergence of Operator Splitting Applied to Conservation Laws With Source Terms

SIAM J. Numer. Anal.

### 1995

#### Journal Articles

A. Tveito and R. Winther

The Solution of Nonstrictly Hyperbolic Systems of Conservation Laws May Be Hard to Compute

SIAM J. Sci. Comput.

### 1994

#### Proceedings, refereed

A. Tveito and R. Winther

A System of Conservation Laws With a Relaxation Term

Proceedings of the fifth international conference on hyperbolic problems

### 1993

#### Journal Articles

A. Tveito and R. Winther

An Error Estimate for a Finite Difference Scheme Approximating a Hyperbolic System of Conservation Laws

SIAM J. Numer. Anal.

#### Technical reports

A. M. Bruaset and R. Winther

Efficient Solution of Linear Equations Arising in a Nonlinear Economic Model

### 1992

#### Journal Articles

H. P. Langtangen, A. Tveito and R. Winther

Instability of Buckley-Leverett Flow in a Heterogeneous Medium

Transport in Porous Media

O. Dahl, T. Johansen, A. Tveito and R. Winther

Multicomponent Chromatography in a Two-Phase Environment

SIAM J. Appl. Math.

#### Proceedings, refereed

A. Tveito, R. Winther and T. Løvereide

Hyperbolic Conservation Laws, Finite Difference Schemes and Error Estimates

Proceedings of the fourth international conference on hyperbolic problems

### 1991

#### Journal Articles

A. Tveito and R. Winther

Existence, Uniqueness and Continuous Dependence for a System of Hyberbolic Conservation Laws Modeling Polymer Flooding

Siam J. of Math. Anal.

### 1990

#### Journal Articles

A. Tveito and R. Winther

Convergence of a Non-Conservative Finite Difference Scheme for a System of Hyperbolic Conservation Laws

J. of Diff. and Integ. Eq.

A. M. Bruaset, A. Tveito and R. Winther

On the Stability of Relaxed Incomplete LU Factorizations

Math. Comp.

### 1989

#### Journal Articles

T. Johansen, A. Tveito and R. Winther

A Riemann Solver for a Two-Phase Multicomponent Process

SIAM Journal on Scientific and Statistical Computing