## Vebjørn H. Bakkestuen

PhD Research Fellow, REGAL project | ||

Affiliation: MatMod group at oslomet.no | ||

Researcher IDs: ORCID, Google Scholar, ResearchGate | ||

Email: vebjorn.bakkestuen@oslomet.no | ||

Address: Pilestredet 35, PS437 |

**About me**

Vebjørn has a background from physics with a focus on quantum mechanics, with both a bachelor and master’s degree in physics from the University of Oslo. He received his master’s degree in theoretical physics form the University of Oslo in the spring of 2023, with a thesis titled “Non-Hermitian Quantum Mechanics: On the role of PT-symmetry and exceptional points”.

**Research Interests**

Vebjørn is currently a PhD candidate working on the mathematical aspects of quantum chemistry, in particular that of Density Functional Theory (DFT). These aspects include the Moreau-Yosida regularisation as well as extensions of DFT.

At the moment he and the group are working on applying and analysing methods from DFT to quantum electrodynamics. In particular, the study of the quantum Rabi model and the generalised Dicke model. He is also working on Kohn-Sham inversion for periodic systems by use of the Moreau-Yosida regularisation of DFT. The analysis of Kohn-Sham inversion includes devising an algorithm for the inversion procedure as well as strict error bounds on the inverted potential. As a proof of example for a recent preprint, this scheme have been applied numerically to bulk silicon.

Vebjørn is currently a part of the ERC project REGAL at OsloMet.

Vebjørn is also co-hosting a workshop on *the Foundations and Extensions of Density-Functional Theory*. Link to webpage.

**Publications**

- Kohn-Sham inversion with mathematical guarantees (Submitted September 2024)
- Quantum-electrodynamical density-functional theory for the Dicke Hamiltonian (Submitted 2024)

**Teaching**

No current teaching responsibilities.

Previously, during the two years as a master’s student at the University of Oslo, Vebjørn was a teaching assistant in the courses FYS2160 – Thermodynamics and Statistical Physics, FYS-MEK1110 – Mechanics, and FYS1100 – Mechanics and Modelling.

**Links**

- Master’s thesis in DUO Research Archive.
- Presentation on a QEDFT model at the Center for Advanced Study at the Norwegian Academy of Science and Letters.
- Poster on Kohn-Sham inversion at the
*Mathematical and Numerical Analysis of Electronic Structure Models*(MANUEL) conference in Stuttgart, Germany September 2024