Recent content by electricspit

Sorry Choppy, I guess it is theoretical physics, but not the math oriented kind I was thinking about. Maybe I just have a romanticized idea of what theoretical physics is supposed to be. My idea of a future in theoretical physics which I would like is doing math physics, I love math and I love...

Hello, I just got an interesting offer and I'm not sure quite what to do. I've always been interesting in theoretical physics, but I've been doing some cosmological simulation research this summer and my advisor was impressed with my work enough to offer me a position as a grad student at my...

Sorry it was fairly zoomed out on the PDF I had. Also thanks!

Hello, I'm trying to get a hang of the definition presented in Arfken - Mathematical Methods for Physicists for 3 dimensional rotations (a setup for an introduction to tensors). That being said I'm a Physicist and I'd like a component approach if possible to the explanation. They give: A_i ' =...

Do you have any book recommendations on this subject? I don't know what dual means really.

The easiest way, cutting all algebra out of the way, is to view a vector as a geometric object. Think of it like a rigid arrow in any coordinate frame you like. Better yet, think of a vector as... a cube. Just a geometric object. You can make infinite coordinate systems surround and envelope...

Right so thanks to TSC for the recommendation. Matterwave: I have no idea what a one form is. I feel like in my 3rd year of physics I should know?

I'd just go read the Wikipedia articles on this but I have and they were slightly confusing. What is the importance of the distinction between the two?

So under specific transformations it acts in different ways?

Right but what does a mixed tensor even mean?

Ah yes sorry I made a typo, I should have read my post over more carefully. Right, I figured it had something to do with g^{in} but I wasn't quite sure, I always forget that I can use dummy indices to multiply through with these things. I'm still not clear on how g^{in} raises the i index. I...

I'm working on the electromagnetic stress-energy tensor and I've found this in a book by Landau-Lifshitz: T^{i}_{k} = -\frac{1}{4\pi} \frac{\partial A_{\ell}}{\partial x^{i}} F^{k\ell}+\frac{1}{16\pi}\delta^{k}_{i} F_{\ell m} F^{\ell m} Becomes: T^{ik} = -\frac{1}{4\pi}...

Hey! I'm planning on applying at some schools in the US next year/this year and I need ot take the GRE exam this fall. I've looked at some old exams and they look pretty straightforward, but I was wondering if anyone knew any resources for the physics exam (i.e. practice tests etc.). Thanks!

Thank you for the information!

Okay so the second question definitely makes a lot of sense now and actually was quite simple. The first question, I don't think I have strong enough understanding of Lagrangian mechanics or tensors to understand. From what I know, Noether's theorem states that if a system has certain...