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Commutator of [x,p e^(-p) ]

  1. Jun 16, 2015 #1
    • Poster has been warned that he needs to show effort before he can be given help
    1. The problem statement, all variables and given/known data
    commutator of [x,p e^(-p) ]

    2. Relevant equations


    3. The attempt at a solution
    answer is i - i.e^(-p)
     
  2. jcsd
  3. Jun 16, 2015 #2

    blue_leaf77

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    what is p in the e^(-p)?
     
  4. Jun 16, 2015 #3
    If it's the usual notation for quantum mechanics, x is position and p is momentum.
     
  5. Jun 16, 2015 #4
    its just the usual commutation relation of x and p with e^(-p) in multiplication.
    the method of solving remains the same.
     
  6. Jun 16, 2015 #5

    blue_leaf77

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    I will assume that the multiplicative factor which should exist next to the momentum in the exponential in order to conform with the dimensionality is presumed to be unity. There is a shortcut formula for calculating commutators of the form [x,f(p)] and [p,g(x)]. In case you never heard about it, you should then do the calculation by first expanding ##e^{-p}## into power series and use the fundamental commutation relation between x and p.
     
  7. Jun 18, 2015 #6

    berkeman

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    You absolutely need to show your efforts before you can get tutorial help here on the PF. That is clear in the PF rules (see Info at the top of the page). This thread is locked. If you want to re-post your question and fill out the Homework Help Template completely, you may do that.
     
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