Paper detail

Many-body excitation spectra of trapped bosons with general interaction by linear response

The linear-response theory of the multiconfigurational time-dependent Hartree for bosons method for computing many-body excitations of trapped Bose-Einstein condensates [Phys. Rev. A {\bf 88}, 023606 (2013)] is implemented for systems with general interparticle interaction. Illustrative numerical examples for repulsive and attractive bosons are provided. The many-body linear-response theory identifies the excitations not unraveled within Bogoliubov--de Gennes equations. The theory is herewith benchmarked against the exactly-solvable one-dimensional harmonic-interaction model. As a complementary result, we represent the theory in a compact block-diagonal form, opening up thereby an avenue for treating larger systems.