What are the needed background to learn Quantum electrodynamics

>>8572814
As the name suggests - quantum mechanics and electrodynamics, plus points if you've done some basic quantum field theory.

Ryder's book on QFT covers some QED as far as I remember, start with that.

>>8572814
Physically, as >>8572853 said, but basically you need everything you learn in your introductory courses, you need special relativity, a lot (4-vectors should be very solid) and you need analytical mechanics (hamiltonian, Lagrangian, Noether's theorem etc).

Mathematically you need all the basic stuff, calculus, linear algebra, differential equations, PDEs, some functional stuff, complex analysis etc, but it's kind of specific and no matter how solid your math is, it will probably be very alien to you. The weirdest part of it is probably somewhere within the gamma matrices. It's not that it's super hard, it's just very weird and you need to get used to it a lot before you actually understand what the fuck you are doing. There's also some QFT stuff that gets extremely weird, like regularization. But I suggest you leave that out at first and start with tree level stuff.

QED really is nothing that is easy to learn when you haven't done all the basic shit before that. It's basically the summit where everything you learn about physics during your undergrad years comes together in one theory. When the ideas presented seem to appear out of nowhere and equations are completely alien to you, it's best you first deal with the foundations it is build on in a little more detail.

>>8572864
Oh, and by the way, electrodynamics as >>8572853 is really not at all that important. What classical electrodynamics deal with is very removed from what you usually do with QED, so fuck it. Basically, what you need to know is Maxwell's equations in the field tensor formulation, that's the only important part. When you see the equation [math]\partial_\mu F^{\mu\nu} = j^\nu[/math] you should understand what you see and you should be able to derive the inhomogenous Maxwell's equations from it. The whole other stuff you usually do with electrodynamics doesn't really matter at all. You should of course know about the phenomenology, but I guess that shouldn't be too much of a problem.

>>8572864
>When the ideas presented seem to appear out of nowhere and equations are completely alien to you, it's best you first deal with the foundations it is build on in a little more detail.
To be honest, I studied differential geometry, Lie groups/algebras and all that stuff in detail and I still don't understand where most of the QED/QFT shit comes from or how it relates to the physical world. All the physics textbooks are so handwavey and unrigorous, jumping from example to example, using confusing notation without explanation and pulling statements out of nowhere.

Not OP btw.

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