The question refers to this paper : http://arxiv.org/abs/1606.00672 I am having difficulty understanding the idea behind this. How can we possibly be able to unambiguously detect any left-over traces of entanglement here ? If I understand this right, the thought process is that an entanglement relationship, and the subsequent process of decoherence, would leave a contribution to the inflationary potential, which then has detectable consequences. The problem I see with this is that it seems to assume us knowing for certain what form the potential would take without any entanglement, or else we wouldn't have anything to compare our data to. My understanding was always that we deduce the form of the inflationary potential from present-day observational data, and not that it somehow follows from fundamental principles. As such, it seems to me that all they are doing is placing constraints on particular forms of the potential, but that doesn't allow us to draw conclusions as to possible entanglement that might have once existed. We are just comparing observational data to something that has been inferred from - well - observational data. In fact, it should be fundamentally impossible to draw conclusions as to entanglement relationships, if only one part of the composite system is considered in isolation, even if that only involves left-over traces like the contribution to the potential. It's like Alice performing measurements on just her own particle, and somehow being able to conclude that the particle must be entangled, without having access to Bob's data. This seems a clear violation of the no-communication theorem to me. In other words - how do we distinguish, within the inflationary potential, between a contribution left-over from an entanglement relationship, and a "natural" contribution that would be there even without the entanglement ? Does the form of the potential follow from more fundamental principles somehow ? Or am I seeing this wrong ? Could someone clarify just what it is the authors of this paper are doing ?