Is there an official list of the postulates of quantum mechanics? - Physics Stack Exchange most recent 30 from physics.stackexchange.com 2019-10-18T09:39:13Z https://physics.stackexchange.com/feeds/question/432743 https://creativecommons.org/licenses/by-sa/4.0/rdf https://physics.stackexchange.com/q/432743 2 Is there an official list of the postulates of quantum mechanics? Meep https://physics.stackexchange.com/users/57218 2018-10-05T16:15:03Z 2018-10-05T16:28:20Z <p>Having been looking at lecture notes, online sources and books, the list of postulates of <a href="https://en.wikipedia.org/wiki/Mathematical_formulation_of_quantum_mechanics" rel="nofollow noreferrer">quantum mechanics</a> seems to vary. For instance, some sources (my lecture notes, for instance) refer to <span class="math-container">$|\langle \psi _i | \Psi \rangle |^2$</span> as the probability of finding the system in a state <span class="math-container">$|\psi _i \rangle$</span>on taking a measurement of observable whose eigenkets are the <span class="math-container">$\{|\psi _i \rangle \}$</span>. While in an online source this is not given as a postulate, but the expectation value of an observable as <span class="math-container">$\int \psi * \hat A \psi$</span> or <span class="math-container">$\langle \psi | \hat A |\psi \rangle$</span> is. Clearly the former implies the latter, however.</p> <p>I realise the development of quantum mechanics wasn't straihtforward, but I was wondering if there is a more authoratative source, perhaps by one of the founding fathers of quantum mechanics, which provides a widely accepted list for <em>the</em> postulates of Qm?</p>