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Dennis Fremstad

Doctoral Research Fellow - Kosmologi
Image of Dennis Fremstad
Visiting address Sem Sælands vei 13 Svein Rosselands hus 0371 Oslo
Postal address Postboks 1029 Blindern 0315 Oslo
Other affiliations Faculty of Mathematics and Natural Sciences (Student)

I am currently working in computational cosmology, with a particular focus on machine learning applications for large-scale structure simulations and cosmological emulation. My research investigates how deep learning methods can be used to generate high-fidelity synthetic universes from computationally inexpensive simulations, enabling efficient modeling of nonlinear structure formation across varying cosmologies. I work extensively with N-body simulations, cosmological statistics, and generative machine learning models, with applications to mock galaxy catalogs and cosmological lightcones for next-generation galaxy surveys.

My broader research interests include cosmological structure formation, dark matter phenomenology, numerical simulations, and scientific machine learning. In particular, I am interested in combining physically motivated simulations with modern deep learning techniques to address computational challenges in cosmology.

I am originally from Norway and have a background in physics and astrophysics. My work combines numerical methods, high-performance computing, and machine learning to study the evolution of structure in the universe across a wide range of scales. I am particularly interested in developing computational tools that bridge the gap between accuracy and efficiency in modern cosmological simulations.

Academic interests

  • Gravity
  • Machine learning for astrophysics
  • Computational cosmology
  • Large-scale structure formation
  • Dark matter phenomenology

 

Background

TimeDegreePlace
2023 - presentPhD in AstrophysicsUiO
2021 - 2023

MSc in Astrophysics

Thesis: Emulating the non-linear matter power spectrum in mixed axion dark matter models

UiO
2018 - 2021BSc in Physics and AstronomyUiO

 

 

Publications

  • Fremstad, Dennis & Winther, Hans Arnold (2025). Emulating the non-linear matter power spectrum in mixed axion dark matter models. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 702. doi: 10.1051/0004-6361/202554621. Full text in Research Archive
  • Fremstad, Dennis; Gomez, Juan Camilo Guevara; Hudson, H. & Oliveros, J. C. Martínez (2023). An overview of HMI off-disk flare observations. Astronomy and Astrophysics (A & A). ISSN 0004-6361. 672. doi: 10.1051/0004-6361/202245788. Full text in Research Archive

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Published Sep. 13, 2023 10:53 AM - Last modified May 27, 2026 1:57 PM