Tim Zimmermann

Tim Zimmermann


PhD candidate

Research group | Cosmology and Extragalactic Astrophysics
Main supervisor | Sijing Shen
Co-supervisor | Hans Winther
Affiliation | Institute of Theoretical Astrophysics, UiO
Contact | tim.zimmermann@astro.uio.no

Short bio

Before starting my position as Ph.D. Research Fellow at the Institute of Theoretical
Astrophysics here in Oslo, I completed both my Bachelors (2018, Thesis: A Simple Model for the Temporal Evolution of Cold Dark Matter) and Masters degree (2020, Thesis: An Investigation of the Lower Dimensional Dynamics of Fuzzy Dark Matter) at Heidelberg University under the supervision of Prof. Luca Amendola and Prof. Sandro Wimberger.

Research interests and hobbies

In short, I’m a computational physicist with a strong interest in cosmology.

More specifically, my primary research interest focuses around the dynamical behaviour and observable consequences of alternative dark matter models such as ultralight dark matter. This work happens at the interface of theoretical modelling, high-performance computing and data/statistical analysis.

CompSci project

Project 2.2

Constraining the properties of wave-like dark matter
in the presence of baryons


The role of dark matter as essential ingredient to the standard model of cosmology is a seldomly disputed fact in the scientific community. Although a variety of observations provide convincing evidence for its existence, its fundamental character remains largely elusive. The lack of evidence for the correctness of Cold Dark Matter (CDM) - our best effective theory - on sub-galactic scales justifies why alternative dark matter models remain an active field of research.

Within the last decade, ultralight dark matter (ULDM), one potential substitute for CDM, has seen considerable interest in the astrophysics community due to its (i) model simplicity (ii) intriguing wave-like dynamical behaviour and (iii) well motivated theoretical origin. If tuned properly, ULDM produces distinct signatures such as cored DM halos and a suppression, or smoothing, of matter structures on length scales smaller than implied by Heisenberg’s uncertainty principle.

In this project I’m interested in how these signatures behave if we increase the model fidelity by adding baryonic -observable- matter and it’s associated feedback processes into the mix. Questions of interest are: How transient are ULDM structures? What observable effects does ULDM imply if baryons are added? Can we distinguish ULDM-effects from baryon-induced signatures? And of course, can we sharpen existing constraints (or find new bounds) of the ULDM parameter space if we increase the physical fidelity of the model?

Simulating these kind of systems is computationally daunting. It is for this reason that I’m also interested in developing cheap surrogate models for ULDM that may help to understand certain aspects of its phenomenology, say quantised vortices, without simulating ULDM from scratch.



CompSci publications

None yet.

Previous publications

  1. Zimmermann, T., Schwersenz, N., Pietroni, M., and Wimberger, S. (2021) "One-dimensional fuzzy dark matter models: Structure growth and asymptotic dynamics",  Phys. Rev. D, 103, 083018. DOI: 10.1103/PhysRevD.103.083018
  2. Zimmermann, T., Pietroni, M., Madroñero, J., Amendola, L., and Wimberger, S. (2019) "A Quantum Model for the Dynamics of Cold Dark Matter", Condensed Matter; 4(4):89. DOI: 10.3390/condmat4040089


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Published June 28, 2022 12:30 PM - Last modified June 28, 2022 12:30 PM