234 citations · 1.6k across the 46 of their papers we have counts for
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Few-body approach to diffraction of small helium clusters by nanostructures
Gerhard C. Hegerfeldt, Thorsten Köhler
We use few-body methods to investigate the diffraction of weakly bound systems by a transmission grating. For helium dimers, He, we obtain explicit expressions for the transiti…
Instantaneous Spreading and Einstein Causality in Quantum Theory
Gerhard C. Hegerfeldt
In nonrelativistic quantum mechanics the wave-function of a free particle which initially is in a finite volume immediately spreads to infinity. In a nonrelativistic theory this is…
Transition from antibunching to bunching for two dipole-interacting atoms
Almut Beige, Gerhard C. Hegerfeldt
It is known that there is a transition from photon antibunching to bunching in the resonance fluorescence of a driven system of two two-level atoms with dipole-dipole interaction w…
Causality, particle localization and positivity of the energy
Gerhard C. Hegerfeldt
Positivity of the Hamiltonian alone is used to show that particles, if initially localized in a finite region, immediately develop infinite tails.