Recent content by kau

By a rigid box what do you mean? At x=0 and at x=L (for a box of length L) the potential is infinity. If that is the case then imposing the periodic boundary condition in the wavefunction, momentum eigenstates are well defined...I mean I donno why it should not be... May be you can explain it to me.

I didn't get the question exactly...But I think what you said is ok. we can say in nearly free electron model that in the edge there is a gap due to superposition of traveling waves directed opposite to each other..Now if the band is filled then it's insulator...and if the fermi momentum lies...

For a free relativistic massive particle ,lagrangian would be ##m\int ds## where ds is the proper time and m is the rest mass..So it is invariant under lorentz transformation. ##ds=\sqrt{\eta_{\mu \nu}dx^{\mu}dx^{\nu}}## So if I parametrize the whole thing with parameter ##\tau## then we have...

If we have periodicity in the wavefunction in position space then momentum is quantized and we can have Fourier series expansion of the wavefunction in terms of momentum wavefunction... Say f(x) is periodic in x [0,L]...Then we have Fourier series expansion ##f(x)=\sum_{k} f_{k}e^{[ikx]}##...

The expression I have written for the quantization of ##\vec{B}## is the same as written in the paper. I copied it from there... The capital ##\vec{W}## sitting in front of the sum over w s is not clear to me..$$ \vec{B}=\frac{\vec{W}}{w}(2h/2\pi wnvs')^{1/2}\sum_{w} b_{w} e^{iw.r}$$.I am trying...

As far as I can understand w is the magnitude of ##\vec{W}## ...and I think it should sit inside the sum...then it would look like usual plane wave decomposition ...but the way it's written here is not clear to me.. i have attached the file..thanks.

Is there anyone who can give some suggestion on this?

I am reading Frohlic's paper on electron-phonon interaction. Frohlic.http://rspa.royalsocietypublishing.org/content/royprsa/215/1122/291.full.pdf Here author has introduced the quantization for complex B field in this paper and claimed to have arrived at the diagonalized form of the...

Somehow I can't relate two things and confused over this. What I understand when someone say that some spacetime has conformal boundary it means that I can write the metric conformally to some other metric where the coordinates are finite ..So it has boundary. Now I just read something on Ads...

Ok. thanks for the response. I have another concern about this. Does this current have anything to do with experiments? can you see them in the experiment or something like that. Or this current just signify the symmetry of the theory and to some extent we can infer if there is some conserved...

I have very simple questions. Although these are simple but I am confused. So if I start with a lagrangian of the following form $$ \mathcal{L} = \partial^{\mu}\phi \partial_{\mu} \phi^{*} -m^{2} \phi^{*} \phi $$ then I get a current for the global invariance of the lagrangian and that is of...

Greens functions are of two types... one is retarded and other one is advanced.. retarded green's functions is causal meaning it respect Lorentz symmetry.. And then you can define Feynman propagator accordingly. Anyway the question of green's function evaluated at same time at same space...

Photons are the quanta of electromagnetic field. So when you turn on electric or magnetic field it's basically filled up with photons. The Higgs particle is the analog of the same thing with Higgs field. There are also the differences In properties of the particles like Higgs are spin zero...

So i came to know that electrons residing across a tiny shell around fermi momentum takes part into the game of forming cooper pair but this phenomenon in real space is actually different. here all the electrons are taking part into this. what does it mean. i am not able to comprehend this...

yeah i looked at that solution where we took a model of perfect liquid inside and got some solution. but you are saying that in case of kruskal we are taking a model where all the mass is at r=0 and otherwise vacuum. ok if i consider this then everything is fine at its place. let me think a...