Recent content by lotm

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    Entanglement and the Pauli exclusion principle

    Hey all, I have what I think (hope) is a relatively quick pair of questions regarding entanglement of fermions and bosons. First, am I right in saying that if two fermions are in the same position-state, they will necessarily be entangled? My reasoning here is just that if their...
  2. L

    (Hopefully easy) integration question

    Yeah, I'm struggling a bit to get the tex code right. Screw it, I'll come back once I've figured out how to ask the question properly.
  3. L

    (Hopefully easy) integration question

    Heyo, I'm having difficulty seeing how these two lines follow. I'm fairly sure I'm being an eejit and the answer's straightforward, but would appreciate a quick explanation of what's going on. \frac{1}{2\pi}\int d^3p e^{-i(\emph{p}^2/2m)t} \\ \times e^{i\emph{p.(x-x_0)}} \\ = (\frac{m}{2...
  4. L

    Raising and lowering indices of partial derivative

    My understanding was that \partial^\mu \phi = g^{\mu\nu}\partial_\nu \phi is used to define the contravariant derivative \nabla^{\mu} (\nabla rather than \partial since we're in GR, though as you've said it reduces to \partial in the case of a scalar function). Given a differentiable...
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    Meaning and derivation of probability

    Yeah, as people have said, it's worth disentangling two separate things: 1. The mathematical 'theory of probability' 2. The interpretation of said theory The first (usually) refers to the consistent mathematical theory described by the Kolmogorov axioms. Other mathematical setups have...
  6. L

    Linear & Vector Algebra: Kronecker delta & Levi-Civita symbol

    The L-C symbol is substantially trickier to get an intuitive handle on - I still don't really have a 'gut feel' for it, even after a few years. The closest thing is probably to understand it as a kind of 'shuffler', which swaps about entries inside matrices in a cyclic sort of way. Hence, it...
  7. L

    Linear & Vector Algebra: Kronecker delta & Levi-Civita symbol

    You said what you were looking for was an intuitive picture of the Kroenecker delta and Levi-Civita symbol? Well, sounds like you're pretty damn close with the delta: I don't quite get why you start talking about vectors - you're on the right track when you say you have a matrix which is...
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