# 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>

<a href=”https://github.com/ernestyalumni/diffgeo-by-sagemnfd/blob/master/spinhelicity.sage”>spinhelicity.sage on github</a><br><br>

<a href=”https://github.com/ernestyalumni/diffgeo-by-sagemnfd/blob/master/Sred_spinor.sage”>Sred_spinor.sage on github</a><br><br>

I wanted to read a little bit of J-Holomorphic curves and I was looking up notes online and found the symplecticfieldtheorist.wordpress.com blog.  It’s really good for symplectic manifolds.  I am amazed also at how much time some (academia) bloggers put into writing LaTeX in html.  I found it to be a pain in the ass and not time and effort efficient at all.  LaTeX for html won’t compile on LaTeX for pdf and vice versa so you end up writing two versions for the same thing.  My solution is I write a pdf and just put it up here for download and export as a .jpg a few tasty pages.

Anyways, I should probably throw up what I can on QFT and spinor helicities right now, finish watching this Ben Cristovao performance on YouTube, and work on some other stuff tonight, and come back to QFT, helicities, and J-Homomorphic curves later.