222 citations · 2k across the 49 of their papers we have counts for
Showing 2022Show all
2 papers · 1 filter
quant-ph2022★ 10 cited
Geometry of Degeneracy in Potential and Density Space
Markus Penz, Robert van Leeuwen
In a previous work [J. Chem. Phys. 155, 244111 (2021)], we found counterexamples to the fundamental Hohenberg-Kohn theorem from density-functional theory in finite-lattice systems…
math-ph2022
Cutting rules and positivity in finite temperature many-body theory
Markku J. Hyrkäs, Daniel Karlsson, Robert van Leeuwen
For a given diagrammatic approximation in many-body perturbation theory it is not guaranteed that positive observables, such as the density or the spectral function, retain their p…