Postdoctoral Researcher
University of Cambridge
Email: frk23@cam.ac.uk
Mathematician working quantitatively with complex systems: quantum, classical and electoral at University of Cambridge. Before that I was at Princeton and in QMATH and NQCP at the University of Copenhagen.
Contact: Danish code, 40 37 23 16.
Below you will find an overview of my research interests as well as a list of publications.
Research Interests
I'm broadly interested in mathematical physics, probability and quantum information and recently also elections.
Publications
A list of my publications can also be found on Google Scholar.
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S. T. Holdum, F. R. Klausen.
Impossibility theorem for two-tier electoral systems , Annals of Operations Research, 2026. (PDF)
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U. T. Hansen, J. Jiang, F. R. Klausen.
A general coupling for Ising models and beyond , Electronic Journal of Probability, 31, 1-32, 2026.
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F. R. Klausen.
Sandsynligheden for overrepræsentation ved Folketingsvalg , Politica, 2026.
- A. J. Bay-Smidt, F. R. Klausen, C. Sünderhauf, R. Izsák, G. C. Solomon, N. S. Blunt.
Fault-Tolerant Quantum Simulation of Generalized Hubbard Models , PRX Quantum, 6, 030348, 2025.
- U. Thinggaard Hansen, F. R. Klausen, P. Wildemann.
Non-uniqueness of phase transitions for graphical representations of the Ising model on tree-like graphs , ALEA, Latin American Journal of Probability and Mathematical Statistics, 22, 889-904, 2025.
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U. Hansen, B. Kjær, F. R. Klausen.
The Uniform Even Subgraph and Its Connection to Phase Transitions of Graphical Representations of the Ising Model , Communications in Mathematical Physics, 2025.
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F. R. Klausen, S. Warzel.
Decoherence is an echo of Anderson localization in open quantum systems , Annales Henri Poincaré, 2025.
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J. Elklit, S. Holdum, F. R. Klausen.
What is wrong with the proportionality in the Parliamentary Elections Act—and what can be done about it? , Politica, 2025.
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D. Harley, I. Datta, F. R. Klausen, A. Bluhm, D. S. França, A. Werner, M. Christandl.
Going Beyond Gadgets: The Importance of Scalability for Analogue Quantum Simulators , Nature Communications, 2024. -
F. R. Klausen, A. Lauritzen.
A stochastic cellular automaton model of culture formation , Phys. Rev. E, 108, 054307, 2023. -
U. Hansen, F. R. Klausen.
Strict monotonicity, continuity and bounds on the Kertész line for the random-cluster model on ℤd , Journal of Mathematical Physics, 2023. -
F. R. Klausen, A. Raoufi.
Mass scaling of the near-critical 2D Ising model using random currents , Journal of Statistical Physics, 2022. -
F. R. Klausen.
On monotonicity and couplings of random currents and the loop-O(1)-model , ALEA, Latin American Journal of Probability and Mathematical Statistics, 2022. -
A. Bluhm, M. Christandl, F. Gesmundo, F. R. Klausen, L. Mančinska, V. Steffan,
D. S. França, A. Werner.
SARS-CoV-2 transmission routes from genetic data: A Danish case study , PloS One, 2020. -
P. Jensen, F. R. Klausen, P. Rasmussen.
Combinatorial classification of quantum lens spaces , Pacific Journal of Mathematics, 2018. -
S. Holdum, F. R. Klausen, P. Rasmussen.
Powers in Prime Bases and a Problem on the Central Binomial Coefficient , Integers: Electronic Journal of Combinatorial Number Theory, 2015. -
S. Holdum, F. R. Klausen, P. Rasmussen.
On a Conjecture on the Representation of Positive Integers as the Sum of Three Terms of the Sequence ⌊n2 / a⌋ , The Journal of Integer Sequences, 2015.
Preprints
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R. Gross, E. Kammerer, F. R. Klausen.
From Kreweras walks to branching perimeter processes of percolated triangulations , 2026. -
U. T. Hansen, F. R. Klausen.
The End of the Double Random Current , 2026. -
U. T. Hansen, F. R. Klausen.
The Supercritical Loop O(1) and Random Current models: Uniqueness and Mixing , 2026. -
F. R. Klausen, N. Kravitz.
Half-plane non-coexistence without FKG , 2026. -
J. Jiang, F. R. Klausen.
A simple proof of exponential decay for the near-critical planar Ising model , 2025. -
F. R. Klausen.
The Disproportionate Power of Votes Near Electoral Thresholds , 2025.