Welcome!
I am a Senior Researcher at the IBS Center for Theoretical Physics of the Universe Cosmology and Gravity group in Daejeon, Korea. My main research interests include the theory and phenomenology of spacetime-symmetry breaking in gravity and cosmology, which I explore using effective-field theory techniques. I am also interested in early-Universe physics, cosmic tensions, and the mathematics of group theory. One of my current long-term projects focuses on Post-Newtonian theory and the generation of gravitational waves by compact sources in the presence of spacetime-symmetry breaking.
- 15 October 2024: I delivered an invited talk on cosmic birefringence at the Workshop on Cosmic Indicators of Dark Matter 2024 at Tohoku University in Japan
- 5-8 October 2024: I participated in the Young Leaders program at the STS Forum 2024 in Kyoto, Japan
- 25 September 2024:My paper on no-go results in gravity with explicit spacetime-symmetry breaking was accepted in Physical Review D. A preprint version can be accessed here
Memberships
I am co-chair of the Early-Career Scientist working group of the LISA (Light Interferometer Space Antenna) consortium, where I also contribute to the Fundamental Physics and Cosmology working groups.
I am on the council of GWECS (Gravitational-Wave Early Career Scientists), where I am also a member of the Science & Research and Career Opportunities offices.
Selected Papers
- “Reexamining aspects of spacetime-symmetry breaking with CMB polarization”, Nils A. Nilsson and Christophe Le Poncin-Lafitte, Phys.Rev.D 109 (2024) 1, 015032, arXiv.
- “Spacetime symmetry breaking effects in gravitational-wave generation at the first post-Newtonian order”,Nils A. Nilsson and Christophe Le Poncin-Lafitte, Phys.Rev.D 109 (2024) 2, 024035, arXiv
- “Explicit spacetime-symmetry breaking and the dynamics of primordial fields”, Nils A. Nilsson, Phys.Rev.D 106 (2022) 10, 104036, arXiv
- “3+1 formulation of the standard model extension gravity sector”, Kellie O’Neal-Ault, Quentin G. Bailey, Nils A. Nilsson, Phys.Rev.D 103 (2021) 4, 044010, arXiv
- “Hořava–Lifshitz cosmology in light of new data”, Nils A. Nilsson and Ewa Czuchry, Phys.Dark Univ. 23 (2019) 100253, arXiv
Career timeline
- 2024 - Present
- Senior Researcher @ CTPU-CGA, Institute for Basics Science, Daejeon, Korea
- 2022 - 2024
- CNES Postdoctoral Fellow @ SYRTE, Observatoire de Paris, France
- 2021 - 2022
- Postdoc @ the Centre for Quantum Spacetime, Sogang University, Seoul, Korea
- 2020
- Ph.D. in Physical Sciences @ the National Centre for Nuclear Research, Warsaw, Poland
Interests
In my free time, I enjoy rock climbing and board games.