Vorträge
2024 | 2023 | 2022 | 2021 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005
2024
A block Householder based QR decomposition of hierarchical matrices
Workshop on Advanced numerical methods for non-local problems, Istanbul, Turkey, Jan. 9-11, 2024
2023
Relaxation in low-rank updates of Schur complement preconditioners in fluid flow problems
10th International Congress on Industrial and Applied Mathematics (ICIAM), Tokyo, August 20-25, 2023
A block Householder based QR decomposition using hierarchical matrices
Workshop on Computational Science and Engineering, Groß Schwansee, 20.-22.3.2023
2022
A block Householder based QR decomposition of hierarchical matrices
GAMM ANLA Conference 2022, Prag, September 22-23, 2022
A block Householder based QR decomposition of hierarchical matrices
GAMM Annual Conference 2022, invited section keynote presentation in section S17: Applied and numerical linear algebra, RWTH Aachen, August 15-19, 2022
Stages of Academia, presentation and discussion in the series Stages of Academia
invitation by UHH SIAM student chapter/GAMM Nachwuchsgruppe, August 9, 2022
A block Householder based QR decomposition of hierarchical matrices
SIAM Annual Meeting 2022, Pittsburgh (hybrid), July 11-15, 2022
2021
Potential (&) pitfalls in RBF-FD discretization of PDEs
Workshop on "Hierarchical Numerical Methods for PDEs", Max-Planck-Institut für Mathematik in den Naturwissenschaften, Leipzig, September 28-29, 2021
Mathematician meets physicist: High performance simulations of next generation light sources
Workshop on "Modeling, Simulation and Optimization of Fluid Dynamic Applications" (GrK 2583), Groß Schwansee, September 6-9, 2021
Der ewige Flaschenhals der Computersimulation - Moderne Verfahren für lineare Gleichungssysteme
Kolloquiumsvortrag im Rahmen des Allgemeinen Vorlesungswesens der Universität Hamburg, 25 May 2021
2019
Numerical techniques for particle aggregation
Kolloquiumsvortrag an der Tennessee Technological University, Cookeville, TN, USA, 3 October, 2019
Preconditioners for RBF-FD discretized fluid-flow problems
GAMM Workshop on Applied and Numerical Linear Algebra, Chemnitz, 26-27 September,
2019
Preconditioners for RBF-FD discretized fluid-flow problems
CIRM Workshop on “Parallel Solution Methods for Systems Arising from PDEs”, Luminy,
France, 16-20 September 2019
Numerical techniques for particle aggregation
6th IMPRS Summer School,
MPI for Dynamics of Complex Technical Systems, Magdeburg, 27. August,
2019
Vorstellung der Graduierten-Schule DASHH
VDI-Abendvortrag in der Reihe
“Datenwissenschaften in Akademie und Industrie”, 15 August, 2019, Helmut-Schmidt-Universität, Hamburg
Factorization and Symmetrization of stabilized Gaussian RBFs
Kolloquiumsvortrag an der TUHH, 11 July, 2019
Fast direct solvers for multilevel RBF interpolation problems
Computational Science & Engineering (CSE) Workshop Plön, March 26-28, 2019
Hierarchical matrices in stable radial basis interpolation
Minisymposium presentation at the SIAM Conference on Computational Science and Engineering,
Spokane, USA, Feb 25 - Mar 1, 2019
Fast direct solvers for RBF interpolation problems
Colloquium at the University Düsseldorf, January 25, 2019
2018
Iterative solvers for RBF interpolation problems
Colloquium at the University Chemnitz, November 30, 2018
Fast solvers for RBF interpolation problems
Invited plenary presentation, Conference on Fast Direct Solvers, Purdue University, Nov. 9-11, 2018
Iterative solvers for RBF interpolation problems
Colloquium at the Tennessee Technological University, Cookeville, TN, USA, November 8, 2018
Reducing computational complexity (using H-arithmetic) in RBF applications
International Conference on Spectral and High Order Methods (ICOSAHOM), Imperial College London, United Kingdom, 9-13th July 2018
(H-matrices for) Stable computations in RBF interpolation problems
Minisymposium presentation at the SIAM Conference on APPLIED LINEAR ALGEBRA, Hong Kong Baptist University, May 4-8, 2018
Toward stable computations in RBF interpolation problems
Computational Science & Engineering (CSE) Workshop Plön, 27.-29.3.2018
2017
Comparison of analytically and algebraically constructed low rank approximations in kernel-based scattered data interpolation
ÖMG-DMV Tagung, 11.-15. September 2017, Salzburg
Comparison of analytically and algebraically constructed low rank approximations in kernel-based scattered data interpolation
Minisymposium presentation at the International Conference On Preconditioning Techniques For Scientific And Industrial Applications 2017, Vancouver, Canada, 31.7. - 2.8.2017
Reducing computational complexity in scattered data interpolation
Workshop on Computational Science and Engineering, Plön, 22. - 24.3.2017
Hierarchical Matrices in Scattered Data Approximation
SIAM Conference on Computational Science and Engineering, Atlanta, Feb 27 - Mar 3, 2017
2016
Hierarchical Matrices in Scattered Data Approximation
Invited Colloquium at the Technical University of Munich, 23.11.2016
Hierarchical Matrices in Scattered Data Approximation
Workshop on "Fast solvers for highly oscillatory problems", Oberwolfach, 3.11.2016,
Tanz elektrischer Ströme und Musik von Radiowellen: Vom Experiment zur Computer-Simulation
Gemeinsamer Vortrag mit Prof. Christian Schuster an der TUHH im Rahmen der Ringvorlesung Technomathematik, 6. Juli 2016
Hierarchical matrices in scattered data approximation with radial basis functions
Norddeutsches Kolloquium at the University of Lübeck, April 22-23, 2016
Hierarchical matrices in scattered data approximation
Keynote speaker of Section 17 "Applied and Numerical Linear Algebra"
at the 87th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM)
2016, March 7-11, 2016, Braunschweig
2015
Hierarchical matrix factorization of the inverse.
Lothar-Collatz-Seminar, University Hamburg, December 3, 2015
Al Capone, Sherlock Holmes und Mathematik.
Public presentation at the "Tag der Mathematik", Universität Hamburg, November 14, 2015
Kann ein Computer rechnen?
Public presentation at the "Nacht des Wissens", Hamburg University of Technology, November 7, 2015
Hierarchical matrix factorization of the inverse.
Minisymposium presentation at the SIAM Conference on Applied Linear Algebra, Atlanta, October 26-30, 2015
3-d shape reconstruction based on 2-d projections of KDP crystals.
Kolloquiumsvortrag an der Tennessee Technological University, Cookeville, TN, USA, Oktober 22, 2015
H-FAINV: Hierarchically Factored Approximate Inverse Preconditioners.
GAMM Workshop on Applied and Numerical Linear Algebra, Max-Planck-Institute for dynamics of complex technical systems, Magdeburg, July 9-10, 2015
H-FAINV: Hierarchically Factored Approximate Inverse Preconditioners.
Conference on Numerical Algebra, Matrix Theory, Differential-Algebraic Equations, and Control Theory, Berlin, May 6-9, 2015 (poster presentation)
Numerical techniques for aggregation integrals in population balance systems.
Norddeutsches Kolloquium at the Jacobs University, Bremen, April 24-25, 2015
Numerische Lösungsverfahren für Aggregationsintegrale in Populationsbilanzsystemen.
Kolloquium an der Christian-Albrechts-Universität zu Kiel, February 12, 2015
2014
Kann ein Computer rechnen?
Presentation at the "Tag der Mathematik", Hamburg, November 22, 2014
Hierarchical Factored Approximate INVerse preconditioners: H-FAINV
European Multigrid Conference, Leuven, Belgien, September 9-12, 2014
Hierarchical Preconditioners for High-Order FEM
Householder Symposium XIX, Spa, Belgien, June 8-13, 2014 (poster presentation)
Preconditioning sparse grad-div/augmented Lagrangian stabilized saddle point problems
Norddeutsches Kolloquium über Angewandte Analysis und Numerische Mathematik, Kiel, May 9, 2014
2013
Preconditioning reduced grad-div stabilized incompressible flow problems
Invited presentation at the International Symposium on Numerics and Scientific Computing, Bruchsal, October 22-24, 2013
Hierarchical preconditioners for higher-order FEM.
Contributed talk at the International Conference on Domain Decomposition Methods (DD22), Universitdella Svizzera italiana - Lugano, Switzerland, September 16-20, 2013
Hierarchical preconditioners for higher-order FEM.
Contributed talk at the GAMM Workshop on Applied and Numerical Linear Algebra, Wuppertal, September 9-10, 2013
Numerical solution methods for coupled population balance systems for the dynamic simulation of multivariate particle processes at the example of shapeselective crystallization.
Project overview at the Kick-off meeting DFG-SPP 1679 "DynSim-FP", Hamburg, August 29, 2013
Hierarchical preconditioners for higher-order FEM.
Invited participant in a minisymposium on "Developments in Preconditioners and Iterative Methods for Linear Systems" at the 25th Biennial Numerical Analysis Conference, Glasgow, UK, June 25-28, 2013
Lösen linearer Gleichungssysteme in der Simulation von Strömungen
Invited presentation within the public lecture series "Mathematische Modellierung in den Natur-, Technik- und Gesellschaftswissenschaften" at the Lothar Collatz Center for Computing Science, University Hamburg, June 4, 2013 (Folien, PDF, 19.464KB)
2012
Hierarchical matrices: Some theory and some applications in preconditioning discretized fluid flow problems.
Invited colloquium talk at the Weierstrass Institute for Applied Analysis and Stochastics, Berlin, October 9, 2012
Hierarchical matrices: past, present, and future.
Invited keynote speaker at the “Scalable Hierarchical Algorithms for eXtreme Computing” workshop (SHACS) at the King Abdullah University of Science and Technology, Thuwal, Saudi Arabia, April 28-30, 2012
Hierarchical matrices: a brief history and some applications in numerical PDEs
Invited colloquium talk at the University of Houston, Texas, April 19, 2012
2011
Hierarchical preconditioners for higher-order FEM.
Invited colloquium talk at Purdue University, Indiana, Nov. 9, 2011 May 22-28, 2011
One-step hierarchical preconditioners for higher order FEM.
Funded participant at the Workshop on “Fast solvers for partial differential equations”, Mathematisches Forschungsinstitut Oberwolfach, May 22-28, 2011
Block preconditioners for saddle point problems.
Invited participant at a minisymposium at the SIAM Computational Science and Engineering Conference in Reno, NV, February 28 - March 4, 2011
Numerical simulation of fluid flow.
Invited presentation at the TTU chapter of Sigma Xi at their luncheon seminar on February, 24, 2011.
Hierarchische Matrizen und ihre Anwendungen in der numerischen Strömungssimulation.
Invited colloquium at the University of Lübeck, Germany, January 21, 2011
Hierarchische Matrizen und ihre Anwendungen in der numerischen Strömungssimulation.
Invited colloquium at the Leuphana University Lüneburg, Germany, January 20, 2011
2010
Poster Title: H-LU factorization of Stabilized Saddle Point Problems.
Funded participant at the Workshop on "Numerical Solutions of Partial Differential Equations: Fast Solution Techniques", Institute for Mathematics and Its Applications (IMA) at the University of Minnesota, MN, November 29 - December 3, 2010.
Hierarchische Matrizen und ihre Anwendungen in der numerischen Strömungssimulation.
Invited seminar presentation at the Hamburg University of Technology, Germany, November 11, 2010
DAAD Alumni Meeting: "Facing the four Elements: Developing a Transatlantic Approach to Sustainability".
October 28-30, 2010, New York City (funded participant)
Attended the Scientific Computing Seminar with emphasis on "Numerical methods for partial differential equations in Eart Sciences".
June 28-30, 2010, Kiel, Germany
Blockpräkonditionierer für Sattelpunktprobleme.
(Invited) seminar presentation at the University of Karlsruhe, Germany, June 8-10, 2010
Funded participant at the Workshop on "Computational optimization for tensor decompositions"
American Institute of Mathematics (AIM), Palo Alto, CA, March 29-April 2, 2010.
Attended the GAMM Seminar on Tensor Approximations and High-Dimensional Problems.
Max-Planck-Institute for Mathematics in the Sciences, Leipzig, Germany, February 22-25, 2010
2009
Hierarchische Matrizen und ihre Anwendungen in der numerischen Strömungssimulation.
Seminar presentation at the Ernst Moritz Arndt University Greifswald, Germany, November 14, 2009
Hierarchical matrix preconditioners.
SIAM Conference on Applied Linear Algebra, Monterey, CA, October 25-30, 2009 (invited to present at the minisymposium on Quasiseparable Matrices and Polynomials)
Hierarchical matrices and their use in preconditioners for saddle point problems.
University of Kentucky, Lexington, invited colloquium talk, October 1, 2009
An Implicit Approximate Inverse Preconditioner for Saddle Point Problems.
International Conference on Preconditioning Techniques for Scientific and Industrial Applications, Hong Kong Baptist University, August 24-26, 2009
Algebraic hierarchical matrix preconditioners for saddle point problems.
Workshop on "Advances and perspectives on numerical methods for saddle point problems", Banff International Research Station, Canada, April 12-17, 2009 (invited)
2008
Blackbox versus geometric methods to construct H-matrices.
Mathematics Graduate Seminar, Tennessee Technological University, November 13, 2008
Blackbox H-preconditioners for two- and three-dimensional saddle point problems.
9th European Multigrid conference, Bad Herrenalb, October 2008, invited plenary lecture
Preconditioned nullspace method for the Oseen problem.
Mathematisches Forschungsinstitut Oberwolfach, Workshop on "Iterative solvers for partial differential equations", May 18-24, 2008 (invited)
Approximate LU and inverse preconditioners for saddle point problems.
Oak Ridge National Lab, invited colloquium talk and collaborative meeting on April 24, 2008
H-matrix preconditioners for the Navier-Stokes equations.
Clemson University, Clemson, SC, invited colloqium talk on March 27, 2008
2007
H-matrix preconditioners for the Navier-Stokes equations.
6th International Congress on Industrial and Applied Mathematics (ICIAM), Zürich, July 2007 (invited to present at the minisymposium on saddle point problems)
Numerical Simulation - Theory and Application.
Poster presentation at the DAAD Pan-American conference in Sao Paulo, Brazil, June 2007
Hierarchical matrix preconditioners for the Oseen equations.
Invited seminar at the University of Lübeck, Germany, April 2007
Discrete divergence-free basis through H-QR factorization.
Invited seminar at the University of Bath, UK, March 2007
2006
Iterative solvers in the simulation of incompressible fluid flow.
Graduate seminar at Tennessee Technological University, October 2006
Domain-decomposition based joint H-matrix preconditioners for saddle point problems.
17th International Conference on Domain DecompositionMethods, Strobl/St. Wolfgang, Austria, July 2-8, 2006.
Block and joint H-matrix preconditioners for the Oseen equations.
2006 Annual GAMM Conference, Berlin, Germany, March 27-31, 2006.
2005
Hierarchical matrix preconditioners for saddle point problems.
8th European Multigrid Conference, Scheveningen, The Netherlands, September 27-30, 2005
Hierarchical matrix preconditioners for saddle point problems.
Invited colloquium talk at the Max-Planck-Institute for Mathematics in the Sciences, Leipzig (Germany), July 2005
Efficient preconditioners and hierarchical matrices.
Invited plenary presentation at the 2005 International Conference On Preconditioning Techniques For Large Sparse Matrix Problems In Scientific And Industrial Applications, Emory University, Atlanta, May 2005
Efficient preconditioners and H-matrices.
Invited colloquium at Oak Ridge National Lab, Computer Science and Mathematics Division, April 2005
Fast solvers through domain decomposition and hierarchical matrices.
Mathematical Graduate Seminar at Tennessee Technological University, Cookeville (USA), February 2005
Domain decomposition based hierarchical matrix preconditioners.
16th International Conference on Domain Decomposition Methods, New York, January 2005
