Mandl & Shaw QFT p.359: Quadratic Equation Examined

[Vic Sandler]

Homework Statement

In the second edition of Mandl & Shaw QFT, on page 359, in the unnumbered eqn below eqn (15.117) it says:
$$N^{\mu\nu}(q - kz, k) = q^{\mu}q^{\nu} - k^{\mu}k^{\nu}z(1 -z) + \cdots$$

Homework Equations

eqn (15.116) on page 358 has a typo in it, but should say:
$$N^{\mu\nu}(p, k) = (p + k)^{\mu}k^{\nu}$$

The first unnumbered eqn at the top of page 359 says:
$$q = p + kz$$

The Attempt at a Solution

I don't see how this can possibly be since eqn (15.116) says N is linear in p and the unnumbered eqn at the top of page 359 says q is linear in p. So how can N be quadratic in q?

 

[mark726]

Hello,

Thank you for bringing this to my attention. After reviewing the equations in question, I believe there may be a typo in the unnumbered equation at the top of page 359. It should say q = p + kz instead of q = p. This would make the equations consistent with each other and allow for N to be quadratic in q as stated in the unnumbered equation below (15.117).

I will reach out to the authors of the book to confirm this and make any necessary corrections. Thank you for your careful observation and for helping to improve the accuracy of scientific publications.