# I’m just gonna put this up; Solutions to Srednicki’s Quantum Field Theory, spinor helicity formalism symbolic computation attempt #2

I was updating my linkedin profile (heh), and I wanted to put up my Notes and Solutions that I wrote for Quantum Field Theory by Mark Srednicki because I continue to refer back to the book and my notes constantly, for academic research, and it’s a delight to read. I tried emailing Dr. Srednicki once to thank him for the book, but he never wrote back.  Ph205, “Relativistic Quantum Mechanics” was the most useful and enjoyable class I took at Caltech, and  I only audited the class.  I really wish someone would video record Ph205 because the lectures are a treasure, and peppered with good jokes.  Some student had a whole video camera setup in 2013-2014 and I suggested that he share the videos somehow, and he gave me some bullshit denial about video rights and legalish.  I think he was just being an jerk to me.  I really want a video up for Ph205.

Srednicki_QFT

<a href=”https://s3.amazonaws.com/patreon/c30ce8c25e170dd6cd8f7126ec2a25da.jpg”>Fig 11.03h for Srednicki solutions on Patreon</a><br><br>

<a href=”https://www.patreon.com/file?s=645287&h=2217718&i=105700″>Srednicki_QFT.pdf on Patreon</a><br><br>

<a href=”https://www.patreon.com/file?s=645287&h=2217718&i=105699″>Srednicki_QFT.tex LaTeX file on Patreon</a><br><br>

I tried rearchitecting spinor helicity formalism with the 4-momentum being points on a smooth 4-manifold $N$.  On Sage Math, I’m still having problems simplifying trigonometric functions to get it to compare with cartesian forms of the 4-momentum when multiplying twistors together i.e. stuff like $|p\langle [ p|$.  What’s a $\latex floor$ in Sage Math after doing a .trig_expand(half_angles=”True”)?

<a href=”https://www.patreon.com/file?s=645287&h=2217732&i=105703″>spinhelicity.sage on Patreon</a><br><br>

<a href=”https://www.patreon.com/file?s=645287&h=2217732&i=105704″>Sred_spinor.sage on Patreon</a><br><br>