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arXiv:2602.01715

Gravitational effects on a dissipative two-level atom in the weak-field regime

Kaito Kashiwagi, Akira Matsumura

quant-phgr-qcSubmitted Feb 2, 2026• Announced Feb 3, 2026• Revised Feb 3, 2026 (v2)

v1 · Feb 2, 2026 v2 · Feb 3, 2026 v3 · May 23, 2026

Abstract

We investigate the dissipative dynamics of a two-level atom in a weak gravitational field. Using the Feynman--Vernon influence functional formalism, we derive a quantum master equation describing the two-level atom interacting with a scalar field in a Newtonian gravitational field, and compute the energy dissipation rate of the atom. We find that the spontaneous emission rate (the dissipation rate in vacuum) is modified by the gravitational field. Specifically, this modification depends on the atom's dipole, the position of the atom relative to the source of the gravitational field, and the frequency of the scalar radiation emitted by the atom. Furthermore, we identify the parameter regimes in which the spontaneous emission rate is enhanced or suppressed by gravity. We also discuss how the modification arises from time dilation and dipole radiation in a weak gravitational field. These findings provide a theoretical basis for exploring gravitational effects in open quantum systems.

Comments: 14 pages + appendices + references, 2 figures; references added, acknowledgement updated

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We investigate the effects of the gravitational field on the quantum dynamics of nonrelativistic particles. We consider

N

nonrelativistic particles, interacting with the linearized gravitational field. Using the Feynman-Vernon influence functional technique, we trace out the graviton field to obtain a master equation for the system of particles to first order in

G

. The effective interaction between the particles as well as the self-interaction is in general non-Markovian. We show that the gravitational self-interaction cannot be held responsible for decoherence of microscopic particles due to the fast vanishing of the diffusion function. For macroscopic particles though, it leads to diagonalization to the energy eigenstate basis, a desirable feature in gravity-induced collapse models. We finally comment on possible applications.