Textbook errata

Scattering Amplitudes in Gauge Theory and Gravity

by Henriette Elvang and Yu-tin Huang.

Cambridge University Press (2015).

ISBN: 9781107069251

Please send a message to elvang(at)umich.(DoNotIncludeThis.)edu when you find a mistake in the book.

Errata: (updated 4/27/2016)

Chapter 2

• p. 18, bottom: the Feynman rules for outgoing fermions should of course have bars on the u_{+/-} in the gray box. Somehow those got erased in the editorial process, booo!

• p. 26, exercise 2.10(c). Missing subscripts "a\dot{b}" on the RHS of the expression for the polarization. (Reyimuaji Yakefu 8/22/2016)

• p. 27 eq (2.55). Missing minus after the last equality. So it should read ... = - <13>[3q]. (Filipe Rudrigues 3/23/2015)

• p. 31 eq (2.67): index mistake - last term should have index structure A^\mu A^\nu A_\mu A_\nu. (João Caldeira 4/27/2016)

• p. 31, eq (2.72): f^{12b} f^{b34} = - Tr(1234) + Tr(1243) + Tr(1342) - Tr(1432). (Steve Naculich and Anatoliy Dovbnya 7/23/2016)

• p. 33, second line, second equation should be [q_2 3] <13> = - [q_2 2] <12>. (João Caldeira 4/27/2016)

• p. 36, eq (2.92) and line below: A_4(...) should be A_4[...] to properly indicate that these are color-ordered amplitudes (three instances). Also, note inconsistency about factors of g^2 between (2.73), (2.91), and (2.92). (Reyimuaji Yakefu 8/22/2016)

Chapter 3

• p. 58, Exercise 3.5. Right above (3.31) the text should refer to Exercise 2.17 instead of Exercise 2.16. (Filipe Rudrigues 3/23/2015)

• p. 66, equation (3.49): the helicity assignment for line 4 in the diagram should be +, not -. (Andrew Ballin, 5/31/2018)

  • p. 67, equation (3.52): the helicity assignment for line 4 in the diagram should be +, not -. (Andrew Ballin, 5/31/2018)

Chapter 4

• p. 76, equation (4.25): subscript on b in the second equation of the first line should be + not -, i.e. it should read [Q,c_+(i)] = [i| b_+(i). (Filipe Rudrigues 3/30/2015)

Chapter 5

• p. 97, equation (5.6): the expression for K_{a \dot{a}} is missing a sum over i. Also, in the expression for Q^{aA} the [i| has an erroneous subscript i (Filipe Rudrigues 5/15/2015)

• p. 100, below (5.20): the (super)twistors scale homogeneously with t_i^{-1}, not t_i. (Filipe Rudrigues 5/15/2015)

Chapter 6

• p. 122, equation (6.15): the second S should have a dagger. Also, it would have been more natural to have called the summation index f (instead of i) since the sum is over all possible final states.

• p. 123, equation (6.19): in the triangle and bubbles integrals, it should be (2\pi)^D instead of (2\pi)^4. (Filipe Rudrigues 6/1/2015)

  • p. 129, equation (6.33): the third integral coefficient (14-channel) is wrong. The numerator should be u (10 s^2 + 2 s u + 3 u^2). (Jung-Wook Kim 12/12/2017 and David Damgaard 12/6/2018)

Chapter 8

• p. 166, equation (8.20): missing equal-sign between the two diagrams. (Fayez Abuajamieh 9/12/2016)

• p. 168, above equation (8.25): the solution $\ell^{(2)}$ forces the vertex to be MHV (not anti-MHV), as indicated correctly in the RHS figure in (8.25). (Fayez Abuajamieh 9/12/2016)

Chapter 9

• p. 187, 11 lines below eq (9.24): k -> (n-k-2) should be k-> n-k. (Xing Wang 6/16/2021)