Welcome!
I work as 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.
- 17-19 March 2025: I will deliver a lecture series on the xAct suite for Mathematica. The workshop website can be found here
- 9-20 December 2024: I visited the Strong Group in at the Niels Bohr Institute in Copenhagen, Denmark
- 27 November 2024:My paper on black-hole solutions in gravity with explicit spacetime-symmetry breaking was submitted to arXiv, and 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.