Here are some notes and solutions to accompany Mark Srednicki's textbook Quantum Field Theory (Cambridge University Press, 2007). As always, I give no guarantee that the solutions are all correct, so if you spot any errors, please do leave a comment.
To download a free pre-publication version of this book, visit the author's web page. This page also contains a list of errata for the published version of the book.
Chapter 1: Attempts at relativistic quantum mechanics
1.1, 1.2, 1.3
Chapter 2: Lorentz invariance
Rotation about an arbitrary axis in 3-D
2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.8