Can gravity account for the emergence of classicality?

Citation data:

Physical Review D, ISSN: 1550-7998, Vol: 92, Issue: 12, Page: 124050

Publication Year:
Usage 115
Downloads 115
Captures 32
Readers 32
Social Media 2
Tweets 2
Citations 7
Citation Indexes 7
Repository URL:
Bonder, Yuri; Okon, Elias; Sudarsky, Daniel
American Physical Society (APS); APS
Physics and Astronomy
Most Recent Tweet View All Tweets
article description
A recent debate has ensued over the claim by Pikovski et al. [Nat. Phys. 11, 668 (2015)] that systems with internal degrees of freedom undergo a universal, gravity-induced, type of decoherence that explains their quantum-to-classical transition. This decoherence is supposed to arise from the different gravitational redshifts experienced by such systems when placed in a superposition of two wave packets at different heights in a gravitational field. Here we investigate some aspects of the discussion with the aid of simple examples. In particular, we first resolve an apparent conflict between the reported results and the equivalence principle by noting that the static and free-fall descriptions focus on states associated with different hypersurfaces. Next, we emphasize that predictions regarding the observability of interference become relevant only in the context of concrete experimental settings. As a result, we caution against hasty claims of universal validity. Finally, we dispute the claim that, at least in the scenarios discussed by Pikovski et al., gravitation is responsible for the reported results, and we question the alleged ability of decoherence to explain the quantum-to-classical transition. In consequence, we argue against the extraordinary assertion by Pikovski et al. that gravity can account for the emergence of classicality.