Markus Kunesch

Career

  • 2017-2018: Research Assistant, School of Mathematical Sciences, Queen Mary University of London and visiting researcher at DAMTP, University of Cambridge
  • 2014-date*: PhD student, DAMTP, University of Cambridge
  • 2010-2014: Mathematical Tripos (MMath/BA), University of Cambridge

*Temporarily withdrawn for the academic year 2017/18 to take up a position as Research Assistant at Queen Mary University of London. Expected date of reinstatement and thesis submission is summer 2018.

Research

Markus is a member of the Relativity and Gravitation research group in the Department of Applied Mathematics and Theoretical Physics. His current research is focused on solving Einstein’s equations numerically to tackle a wide range of problems in astrophysics, cosmology, mathematical general relativity, and AdS/CFT.

Publications

  • Bantilan, H., Figueras, P., Kunesch, M., & Romatschke, P. (2017). Non-Spherically Symmetric Collapse in Asymptotically AdS Spacetimes. To appear in: Physical Review Letters
  • Figueras, P., Kunesch, M., Lehner, L., & Tunyasuvunakool, S. (2017). End Point of the Ultraspinning Instability and Violation of Cosmic Censorship. Physical Review Letters118(15), 151103.
  • Figueras, P., Kunesch, M., & Tunyasuvunakool, S. (2016). End point of black ring instabilities and the weak cosmic censorship conjecture. Physical Review Letters116(7), 071102 (Editors' Suggestion).
  • Cook, W. G., Figueras, P., Kunesch, M., Sperhake, U., & Tunyasuvunakool, S. (2016). Dimensional reduction in numerical relativity: Modified Cartoon formalism and regularization. International Journal of Modern Physics D25(09), 1641013.
  • Clough, K., Figueras, P., Finkel, H., Kunesch, M., Lim, E. A., & Tunyasuvunakool, S. (2015). GRChombo: Numerical relativity with adaptive mesh refinement. Classical and Quantum Gravity32(24), 245011.

Research highlights

Higher dimensional black holes
We performed simulations that showed that the higher dimensional analogues of the black holes in our universe can break. Previously, this was only known for higher dimensional black holes with a rolled-up extra dimension (Lehner&Pretorius, PRL 105, 101102). General Relativity cannot describe the process of a black hole breaking, so in this setup the theory predicts its own demise. 

Simulation of a six dimensional black hole being torn apart by its own rotation.

In the process of hunting for black holes that break, we also uncovered a previously unknown instability of black rings in five dimensions: an elastic instability, which stretches the black ring without changing its thickness substantially.

GRChombo
In our simulations, we need to be able to resolve many different length scales efficiently. To this end, we have developed GRChombo, a new numerical relativity code with fully adaptive mesh refinement. In the last few years, GRChombo has been used for many different problems ranging from cosmology to higher dimensional black holes. More information can be found at grchombo.github.io.