Asbjørn Bækgaard Lauritsen

About Me

I am a Ph.D. student in mathematical physics at IST Austria in the group of Robert Seiringer. Prior to this I did my master’s degree at the University of Copenhagen, where I wrote my thesis under supervision of Jan Philip Solovej.

Research Interests

I am interested in the mathematics of many-body quantum systems. More specifically, in my Ph.D. project I study the ground state energy of a dilute spin-polarized Fermi gas.

Brief CV

2020 - present: Ph.D., IST Austria
2018 - 2020: M.Sc. in mathematics, University of Copenhagen
2015 - 2018: B.Sc. in mathematics, University of Copenhagen

Publications

Dilute Fermi gases

• Ground state energy of the dilute spin-polarized Fermi gas: Lower bound
  A. B. Lauritsen and R. Seiringer, arXiv:2402.17558 (2024)
• Pressure of a dilute spin-polarized Fermi gas: Lower bound
  A. B. Lauritsen and R. Seiringer, arXiv:2307.01113 (2023)
• Almost optimal upper bound for the ground state energy of a dilute Fermi gas via cluster expansion
  A. B. Lauritsen, arXiv:2301.08005 (2023)
• Ground state energy of the dilute spin-polarized Fermi gas: Upper bound via cluster expansion
  A. B. Lauritsen and R. Seiringer, J Funct Anal. 286 (7) p. 110320 (2024)
• (Supplementary material: Code on GitHub for calculating values of GGR-diagrams)

BCS theory

• Universal behavior of the BCS energy gap
  J. Henheik and A. B. Lauritsen, arXiv:2312.11310 (2023)
• Universality in low-dimensional BCS theory
  J. Henheik, A. B. Lauritsen, and B. Roos, Rev. Math. Phys. p. 2360005 (2023)
• The BCS Energy Gap at High Density
  J. Henheik and A. B. Lauritsen, J. Stat. Phys. 189, 5 (2022)
• The BCS energy gap at low density
  A. B. Lauritsen, Lett. Math. Phys. 111.20 (2021)

Culture formation

• Stochastic cellular automaton model of culture formation
  F. R. Klausen and A. B. Lauritsen, Phys. Rev. E 108.5 (2023)
  (Supplementary material: Code on GitHub and Research data)

Jellium and the Uniform Electron Gas

• Floating Wigner crystal and periodic jellium configurations
  A. B. Lauritsen, J. Math. Phys. 62, 083305 (2021)

Theses

• A mathematical formulation of the Bardeen-Cooper-Schrieffer theory of superconductivity
  M.Sc. thesis in mathematics, University of Copenhagen (2020)
  (Supplementary material: Proof of Equation (5.8))
• Representations of the Poincaré Group
  B.Sc. thesis in mathematics, University of Copenhagen (2018)