1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Zwiebach page 292

  1. Nov 26, 2007 #1
    1. The problem statement, all variables and given/known data
    In equation 14.81, why are the lower indices of the oscillators alpha^r and alpha^s not divided by 2 like they were in equation 14.77?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Nov 26, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    In my edition, equation 14.81 has no alpha (it has integrals with exponentials) . But my equation 14.82 has the commutator of alpha^r and alpha^s and they have, respectively, the subscripts m/2 and n/2.
    I am not sure if you have that.
  4. Nov 26, 2007 #3
    I'm sorry. I meant 14.80. Mine has subscripts of m and n (not divided by 2) so it must be a typo. That would make much more sense since the commutator of 14.82 in my book does have subscripts that are divided by 2.
    Last edited: Nov 26, 2007
  5. Nov 27, 2007 #4
    I'm pretty sure it's a typo. Here is Professor Zwiebach's errata page. It has his e-mail address where you can send him this one.

    http://xserver.lns.mit.edu/~zwiebach/firstcourse.html" [Broken]
    Last edited by a moderator: May 3, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook