Quantum Theory and Beyond: Is Entanglement Special? · HackerPapers discussions

Quantum Theory and Beyond: Is Entanglement Special? — mentioned by magicalhippo

Fri, 22 Dec 2023 19:36:09 GMT

Reminds me of a paper by by Hardy[1] where he introduces five reasonable axioms (his words). Classical and quantum probability theory obeys the first four. However the fifth, which states that there exists continuous transformations between pure states, is only obeyed by the quantum theory. In that sense he argues that quantum theory is in a sense more reasonable than classical theory. There's also an interesting link between this and entanglement[2] which seems to rule out other probability theories, leaving only quantum theory able to exhibit entanglement. Not my field at all though, just…

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Quantum Theory and Beyond: Is Entanglement Special? — mentioned by magicalhippo

Wed, 22 Dec 2021 12:29:56 GMT

Lucien Hardy wrote a paper[1] showing how one "naturally" ends up with a quantum theory by demanding a few reasonable axioms. The paper also goes into how this implies complex numbers (and rules out quaternions). Scott Aaronson has a more accessible (and humorous) article on it here[2]. Entanglement has been shown to be intimately linked to this[3] result, which is interesting given the experimental evidence[4] for entanglement. Not my field, but I found this interesting at least. [1]: https://arxiv.org/abs/quant-ph/0101012 [2]: https://www.scottaaronson.com/democritus/lec9.html [3]…

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Quantum Theory and Beyond: Is Entanglement Special? — mentioned by cevi

Sun, 17 Oct 2021 14:49:17 GMT

Unlike perpetual motion or free energy, the math and physics behind quantum computing is rock solid - the possibility is baked into the framework of quantum mechanics at an absolutely fundamental level. Even if it turned out that all of quantum field theory was completely bogus, I would still expect the basic framework of quantum mechanics (i.e. unitary evolution, the Born rule for converting amplitudes to probabilities, density matrices describing mixed states) to be correct. If quantum computing was not possible, that would mean that everything we thought we knew about physics was…

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