Disputation: Karl Erik Holter

Doctoral candidate Karl Erik Holter at the Department of informatics, Faculty of Mathematics and Natural Sciences, is defending the thesis Robust preconditioning of multiphysics problems and interstitial fluid flow for the degree of Philosophiae Doctor.

Picture of the candidate

Photo: Private

The University of Oslo is closed. The PhD defence and trial lecture will therefore be fully digital and streamed directly using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.

Ex auditorio questions: the chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking 'Participants -> Raise hand'. 

Trial lecture

Title: "Finite element approximation of eigenvalue problems"

Main research findings

Bildet kan inneholde: skråningen, skrift, parallell, triangel, rektangel.In the natural sciences, there are many examples of physical systems which can be modeled by differential equations, such as the flow of water through soil or the deformation of a bridge under load. By developing mathematical techniques for solving the resulting equations with a computer, we can use these models to answer questions such as how much weight a bridge can support before collapsing.

Complex systems often involve multiple interdependent kinds of physical behavior. An example is the brain, where water movement occurs both inside blood vessels and in the surrounding brain tissue. Because the two kinds of flow affect each other through interchange across the vessel walls, a model of water movement in the brain must account for both.

However, even when there are robust methods for solving either subproblem individually, coupling them together in a robust manner is not always straightforward, and the focus of this thesis. Robustness means that the method should run in a reasonable amount of time, both for complex problems with many unknowns and for all values of the problem parameters, even the very large or very small. This property is crucial for applications such as water movement in the brain.

Adjudication committee:

  • Professor Lucia Gastaldi, University of Brescia, Italy
  • Associate Professor Mingchao Cai, Morgan State University, USA
  • Professor Snorre Christiansen, Department of Mathematics, University of Oslo, Norway


  • Professor Kent-Andre Mardal, Department of Mathematics, University of Oslo, Norway
  • Professor Anders M. Dale, University of California, San Diego
  • Associate Professor Unn Kristin H. Haukvik, Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Norway

Chair of defence

  • Professor & Head of Department Stephan Oepen, Department of Informatics, UiO

Contact information to Department: Anniken R. Birkelund

Publisert 9. apr. 2021 09:43 - Sist endret 21. apr. 2021 14:34