Recent content by c299792458

Thank you, Giga_Man!

Please, somebody? OK, so I know that the density of state depends on the dispersion relation. What are the general definitions of E, p in terms of \omega, k? E.g. for the first case E=\hbar \omega and p=\hbar k. So the question is: what are the respective values for E,p in general?

Homework Statement I have seen case studies of the 3D Debye model where the vibrational modes of a solid is taken to be harmonic with dispersion relation \omega = c_sk. It is said that for temperatures much less than the Debye temperature, the heat capacity at constant volume C_V\sim T^3...

Suppose there is a semiconductor with Fermi energy $E_f$ and that there are $N$ bound electron states. I'd like to know why the mean number of excited electrons takes the form \bar n(T)={N\over \exp\beta(\mu-E_f)+1} where \mu is the chemical potential. ____ I can see that the Fermi...

Let us denote by X^i=(1,\vec 0) the Killing vector and by u^i(s) a tangent vector of a geodesic, where s is some affine parameter. What physical significance do the scalar quantity X_iu^i and its conservation hold? If any...? I have seen this in may books and exam questions. I wonder what it...

Could somebody please explain something regarding the Nordstrom metric? In particular, I am referring to the last part of question 3 on this sheet -- http://www.hep.man.ac.uk/u/pilaftsi/GR/example3.pdf about the freely falling massive bodies. My thoughts: The gravitational effects...

Thank you, bcrowell!

Is a negative zeroth-component of a four-velocity V^0 with a curved space metric of signature -+++ allowed?

Would someone please explain the following found on P. 125 of these notes http://www.hep.phys.soton.ac.uk/hepwww/staff/D.Ross/phys3002/PCCP.pdf? >On the other hand, two π^0’s cannot be in an l = 1 state. The reason for this is that pions are bosons and so the wavefunction for two identical...

No worries. Problem resolved. Thanks for reading anyways.

Homework Statement We have a system of 2 indistinguishable spin-1 bosons. We shall adopt the center of mass frame. Let S = total spin L = relative orbital angular momentum J = L+S = total angular momentum Prove that J = 2m where m is an integer. If given that J=1, what are the permissible...

@DarthFrodo: Thank you. Actually the Math course at my university does cover Statistical Physics, E&M, etc. Though not topics like condensed matter, solid state physics, etc. A double major is not available at my university.

I am hoping to become a physicist focusing mainly on the theoretical side in the future. I am trying to decide whether to go for a physics or math undergrad course. Assuming that I am capable of doing either, what are the pros and cons of either route? I know that mathematics is essential to...

@M Quack: Thank you. I don't know how to change these into vectors, could you please kindly give me another nudge? Thanks again.

Homework Statement We are given an infinitely long cylinder of radius b with an empty cylinder (not coaxial) cut out of it, of radius a. The system carries a steady current (direction along the cylinders) of size I. I am trying to find the magnetic field at a point in the hollow. I am told that...