Classical Gravity Distorts Quantum Snapshots ⚡ экспресс
The influence of classical gravity (Schrödinger–Newton theory) on the continuous quantum tomography of a macroscopic mechanical oscillator with homodyne detection is investigated. Unlike quantum mechanics, in the SN model, the measurement record reflects a different conditional dynamics, which, upon quantum-optimal reconstruction, introduces a state-dependent contribution. This makes the reconstructed covariance matrix sensitive to tomography angles and can push it beyond the Heisenberg limits. The distinguishability of the models is evaluated using the Hellinger distance and studied as a function of measurement strength and temperature. The consideration is generalized to nonlinear quantum mechanics: when the conditional dynamics during readout depend on the state itself, the tomographic map acquires nonlinear corrections.
Photographing hummingbird wings with an ordinary camera gives a blurry smudge. For a sharp picture, you take many rapid shots from different angles and piece them together—that's how a quantum 'snapshot' is made. In the lab, scientists 'feel' the vibrations of a tiny mirror with a laser beam. By tracking changes in the light, they reconstruct the quantum state of this motion.
But gravity might behave differently. The Schrödinger–Newton theory suggests it remains a classical field. Then the mirror's own gravity makes it jiggle in sync with the measurement—like a camera shaking in unison with the subject. The resulting 'photograph' violates a fundamental ban—the Heisenberg uncertainty limit—like an impossibly ultra-sharp frame. Such anomalies would be a signal: if they appear, gravity is classical. It's a way to test the nature of gravity in the lab; if it turns out to be quantum, gravitational waves would appear as a stream of particles.
🎯 According to the Schrödinger-Newton theory, every object gravitationally attracts itself, and this tiny force can distort a quantum experiment.