# ARE QUANTUM STATES REAL

@article{Hardy2012AREQS, title={ARE QUANTUM STATES REAL}, author={Lucien Hardy}, journal={International Journal of Modern Physics B}, year={2012}, volume={27}, pages={1345012} }

In this paper we consider theories in which reality is described by some underlying variables, λ. Each value these variables can take represents an ontic state (a particular state of reality). The preparation of a quantum state corresponds to a distribution over the ontic states, λ. If we make three basic assumptions, we can show that the distributions over ontic states corresponding to distinct pure states are nonoverlapping. This means that we can deduce the quantum state from a knowledge of…

## 103 Citations

No ψ-epistemic model can fully explain the indistinguishability of quantum states.

- Physics, MedicinePhysical review letters
- 2014

This work considers models that are defined for a single quantum system of dimension d, such that the independence condition does not arise, and derives an upper bound on the extent to which the probability distributions can overlap.

Conclusive exclusion of quantum states and aspects of thermo-majorization

- Mathematics
- 2016

Part 1: Why can we not distinguish between pure, non-orthogonal quantum states? Regarding the quantum state as a state of knowledge rather than something physically real, has the potential to answer…

Experimental refutation of a class of ψ -epistemic models

- Physics
- 2013

The quantum state $\ensuremath{\psi}$ is a mathematical object used to determine the outcome probabilities of measurements on physical systems. Its fundamental nature has been the subject of…

On Modern Approaches to the Einsteinian View of Quantum States

- Mathematics
- 2016

Quantum mechanics notoriously faces the measurement problem, the problem that if read thoroughly, it implies the
nonexistence of deﬁnite outcomes in measurement procedures. A plausible reaction to…

Can different quantum state vectors correspond to the same physical state? An experimental test

- Physics
- 2012

A century after the development of quantum theory, the interpretation of a quantum state is still discussed. If a physicist claims to have produced a system with a particular quantum state vector,…

Is the Quantum State Real in the Hilbert Space Formulation?

- Computer ScienceQuanta
- 2020

It is shown that an unambiguous proof of reality of the quantum states gleaned from thereality of quantum fields can also provide an explicit substantiation of the reality of quantum states in Hilbert space.

Is a time symmetric interpretation of quantum theory possible without retrocausality?

- Physics, MathematicsProceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
- 2017

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.

Reality, causality, and quantum theory

- Mathematics, Physics
- 2017

Quantum theory describes our universe incredibly successfully. To our classically-inclined brains, however, it is a bizarre description that requires a reimagining of what fundamental reality, or…

No-go theorems for ψ-epistemic models based on a continuity assumption.

- Mathematics, PhysicsPhysical review letters
- 2013

This argument is different from the recent proof of Pusey, Barrett, and Rudolph and it already yields a nontrivial constraint on ψ-epistemic models using a single copy of the system in question.

ψ-Epistemic Models, Einsteinian Intuitions, and No-Gos. A Critical Study of Recent Developments on the Quantum State

- Physics, Mathematics
- 2016

Quantum mechanics notoriously faces the measurement problem, the problem that if read thoroughly, it implies the nonexistence of definite outcomes in measurement procedures. A plausible reaction to…

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