Recent content by lion8172

I read somewhere that the Hall conductance is proportional to the derivative of the density of states at the Fermi level, and somewhere else that the longitudinal resistivity is proportional to the density of states at the Fermi level. Does anyone happen to know which it is?

I was looking at a derivation of the Landau levels in a crystal, and I had a question about the Landau gauge. The situation under consideration is a two dimensional system of non-interacting particles, exposed to a uniform magnetic field B directed along the z-axis (perpendicular to the plane of...

He worked as a speechwriter for the McGovern campaign, not the Goldwater campaign. I'm also curious as to whether he studied math/physics as an undergraduate. Given the fact that he originally enrolled as an applied mathematics graduate student at Princeton, I would say that it's likely he had...

I was wondering if someone could clarify something that I read in a book (Nakahara's book on Geometry, Topology, Physics). In the section on the Einstein-Hilbert action, the author defines the energy-momentum tensor as \delta S_M = \frac{1}{2} \int T^{\mu \nu} \delta g_{\mu \nu} \sqrt{- g} d^4...

I meant how does it look as an undergraduate course. I am an undergrad, yes.

Homework Statement Find the wave function of the ground energy state for a system of two non-interacting, identical spin 1/2 particles in a potential well extending from x=0 to x=a. Don't forget to consider spin.Homework Equations The Attempt at a Solution Since the particles are fermions...

Speaking as a physics major, (and not an engineer of course), I would say that your physics background is more than sufficient. You will have a leg up in that respect. Your math background, however, may be a bit lacking (but not that much necessarily). What do you mean by Calc I? Have you done...

I am a physics major and I have taken many math courses, but not Complex Variables. I did a little contour integration along time ago, but I never took it as a course. I do, however, have the option to take this semester. Should I take it instead of another physics elective? I know that it is...

Does a physics reading course make a good impression on an undergraduate transcript? If given the choice between taking a reading course in an interesting subject and taking the same course as a regular class the following year, what would you do?

The quantum class was at the level of Griffiths, and the QFT class is at the level of Peskin & Schroeder.

Is one semester of quantum sufficient preparation for a QFT course?

Yes.

I know that the highest weight of an irreducible representation is unique (up to scaling). Is the converse true, however? I have seen some proofs of the irreducibility of certain representations that proceed by showing the uniqueness of the highest weight. How do we know that this is a valid...

In the chapter on radiation (Chapter 11), Griffiths notes that an electric monopole does not radiate, but also that a point charge of electric dipole moment \mathbf{p} (t) = q \mathbf{d} (t) (where \mathbf{d} (t) is the instantaneous coordinate of the charge with respect to a fixed origin )...

Does anybody know of a nice, intuitive way to remember the second and third isomorphism theorems?