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arXiv · 2604.11976

Effective Dynamics for the Bose Polaron in the Large-Volume Mean-Field Limit

Jonas Lampart·Peter Pickl·Siegfried Spruck
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Abstract

We consider the dynamics of the Bose polaron system, a dense quantum gas consisting of $N$ bosons evolving in $\mathbb{R}^3$ in the presence of an impurity particle. The system is studied in the mean-field scaling with initially high density $ρ$ and large volume $Λ$ of the gas. In the initial state, almost all bosons are in the Bose-Einstein condensate, with a few excitations. We derive from the microscopic dynamics, in the joint limit of large densities and volumes, with the constraint $Λ^3 \ll ρ$, the effective description by the translation-invariant Bogoliubov-Fröhlich Hamiltonian, which couples the quantum field of excitations linearly to the impurity particle.

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Jonas Lampart, Peter Pickl, Siegfried Spruck. 2026-05-22. Effective Dynamics for the Bose Polaron in the Large-Volume Mean-Field Limit. https://arxiv.org/abs/2604.11976

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