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Ground State of a Quantum Particle Coupled to a Scalar Bose Field


We use methods from functional integration to prove the existence and uniqueness of the ground state of a confined quantum particle coupled to a scalar massless Bose field. For an external potential growing at infinity, the ground state exists under fairly general conditions while, for a decaying potential, an unphysical condition on the coupling strength is still needed.

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Spohn, H. Ground State of a Quantum Particle Coupled to a Scalar Bose Field. Letters in Mathematical Physics 44, 9–16 (1998).

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  • ground state
  • functional integration
  • particle and field.