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On interacting fermions and bosons with definite total momentum

Ofir E. Alon·Alexej I. Streltsov·Lorenz S. Cederbaum
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Abstract

Any {\it exact} eigenstate with a definite momentum of a many-body Hamiltonian can be written as an integral over a {\it symmetry-broken} function $Φ$. For two particles, we solve the problem {\it exactly} for all energy levels and any inter-particle interaction. Especially for the ground-state, $Φ$ is given by the simple Hartree-Fock/Hartree ansatz for fermions/bosons. Implications for several and many particles as well as a numerical example are provided.

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Ofir E. Alon, Alexej I. Streltsov, Lorenz S. Cederbaum. 2004-06-14. On interacting fermions and bosons with definite total momentum. https://doi.org/10.1103/physrevb.71.125113

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