A no-go theorem on the reality of the quantum state is demonstrated. If the quantum state merely represents information about the physical state of a system, then predictions that contradict those of… Expand

This work generalizes the formalism of classical Bayesian networks in order to investigate non-classical correlations in arbitrary causal structures, and finds that no probabilistic theory predicts perfect correlation between three parties using only bipartite common causes.Expand

It is shown that the assumption that a time symmetric ontology for quantum theory must necessarily be retrocausal can be replaced by a different assumption, called λ-mediation, that plausibly holds independently of the status of the quantum state, and that this assumption implies a timelike analogue of Bell's local causality criterion.Expand

It is shown that entanglement can be analyzed in terms of three geometric features of the ellipsoid and proved that a state is separable if and only if it obeys a "nested tetrahedron" condition.Expand

The violation of a Bell inequality certifies the presence of entanglement even if neither party trusts their measurement devices. Recently Moroder et al. [T. Moroder, J.-D. Bancal, Y.-C. Liang, M.… Expand

This work presents a simple method for building LHV models, applicable to any entangled state and considering continuous sets of measurements, which leads to a sequence of tests which fully captures the set of quantum states admitting a LHV model.Expand

This work shows how to devise tests that are free of idealizations that real experiments cannot achieve, namely noiseless measurements and exact operational equivalences, and performs a photonic implementation of one such test, ruling out noncontextual models with high confidence.Expand

It is shown that "anomalous weak values" are nonclassical in a precise sense: a sufficiently weak measurement of one constitutes a proof of contextuality, which clarifies, for example, which features must be present to demonstrate an effect with no satisfying classical explanation.Expand

This work identifies five criteria for a quantum joint state over time to satisfy if it is to play a role similar to the standard joint state for a composite system, and shows that no construction satisfies all these requirements.Expand

This perspective sheds light on why the BB84 key distribution protocol can be secure, even with an untrusted measuring device, leading to an uncertainty relation for arbitrary pairs of ensembles.Expand