



01475nas a2200121   4500008004100000245003200041210003200073260001400105520115600119100001901275700002201294856003701316       2023                        eng d00aStrongly incoherent gravity0 aStrongly incoherent gravity  c1/20/20233 a<p>While most fundamental interactions in nature are known to be mediated by quantized fields, the possibility has been raised that gravity may behave differently. Making this concept precise enough to test requires consistent models. Here we construct an explicit example of a theory where a non-entangling version of an arbitrary two-body potential V(r) arises from local measurements and feedback forces. While a variety of such theories exist, our construction causes particularly strong decoherence compared to more subtle approaches. Regardless, expectation values of observables obey the usual classical dynamics, while the interaction generates no entanglement. Applied to the Newtonian potential, this produces a non-relativistic model of gravity with fundamental loss of unitarity. The model contains a pair of free parameters, a substantial range of which is not excluded by observations to date. As an alternative to testing entanglement properties, we show that the entire remaining parameter space can be tested by looking for loss of quantum coherence in small systems like atom interferometers coupled to oscillating source masses.</p>1 aCarney, Daniel1 aTaylor, Jacob, M.  uhttps://arxiv.org/abs/2301.08378