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!

Derivative of d'Alambert operator?

  1. Nov 11, 2014 #1
    Hi guys,

    So I've ended up in a situation where I have [itex]\partial_{\mu}\Box\phi[/itex]. where the box is defined as [itex]\partial^{\mu}\partial_{\mu}.[/itex] I'm just wondering, is this 0 by any chance...?

  2. jcsd
  3. Nov 12, 2014 #2


    User Avatar
    Gold Member

    You shouldn't use same greek letters. Because the d'Alembertian of a scalar field is a scalar and when you differentiate that, you'll get a vector. So you should write [itex] \partial_\nu \Box \phi=\partial_\nu (\partial^\mu \partial_\mu \phi) [/itex]. I don't see a reason that makes it zero identically!
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook