19 citations · 29 across the 5 of their papers we have counts for
5 papers
From Symmetry and Reduction to Physically Meaningful Relational Observables in Many-Body Quantum Theory
Ville J. Härkönen
We consider symmetries and reduction in non-relativistic many-body quantum mechanics, with the aim of identifying physically meaningful observables in systems such as molecules and…
Breakdown of the Born-Oppenheimer approximation in solid hydrogen and hydrogen-rich solids
Ville J. Härkönen
Hydrogen has been the subject of intense research following the discovery of high-temperature superconductivity in hydrides, and as a result of continuous efforts to produce solid…
Exact factorization of the many-body Green's function theory of electrons and nuclei
Ville J. Härkönen
We combine the recently developed many-body Green's function theory for electrons and nuclei with the exact factorization of the wave function. The existing Born-Oppenheimer Green'…
Many-body Green's function theory of electrons and nuclei beyond the Born-Oppenheimer approximation
Ville J. Härkönen, Robert van Leeuwen, E. K. U. Gross
The method of many-body Green's functions is developed for arbitrary systems of electrons and nuclei starting from the full (beyond Born-Oppenheimer) Hamiltonian of Coulomb interac…
Elastic constants and thermodynamical quantities for crystal lattices from many-body perturbation theory
Ville J. Härkönen
The method of many body Green's functions is used to derive algebraic expressions for the different elastic and thermodynamical quantities such as the free energy, internal energy,…