Beyond the Boltzmann equation for weakly coupled quantum fields

Xu-Yao Hu; Vladimir Rosenhaus

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arXiv · 2503.09932

Beyond the Boltzmann equation for weakly coupled quantum fields

Xu-Yao Hu·Vladimir Rosenhaus

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Abstract

We study the kinetic theory of a weakly interacting quantum field. Assuming a state that is close to homogeneous and stationary, we derive a closed kinetic equation for the rate of change of the occupation numbers, perturbatively in the coupling. For a dilute gas, this reproduces the quantum Boltzmann equation, which only accounts for two-to-two scattering processes. Our expression goes beyond this, with terms accounting for multi-particle scattering processes, which are higher order in the density.

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Xu-Yao Hu, Vladimir Rosenhaus. 2025-03-13. Beyond the Boltzmann equation for weakly coupled quantum fields. https://arxiv.org/abs/2503.09932

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