Recent content by Lonewolf

I read a problem a while ago which was to find a differential form on the circle which is not the differential of any function. Being a hapless physicist, this puzzled me for a while. I've found an answer in Spivak's Calculus on Manifolds, but I need a little help in following his reasoning...

You're asking a hell of a question. Are you familiar with classical integrable systems? The question is so wide that only a short reply is appropriate. There are a variety of approaches, mainly Bethe Anzatz, and quantum inverse scattering are used. i) The main point of integrable QFT is we need...

It is called telif haklari in Turkish, özgur. Çok hoşgeldiniz :)

It does indeed seem odd. Are you sure the hermitian conjugate isn't present?

Frustration occurs when a system is unable to simultaneously achieve a minimum energy for each entity involved. For example, if you take the antiferromagnetic Heisenberg model on a triangular lattice, the ground state cannot be the Néel state, since there will always be one unhappy bond. The...

I agree in principle, but shouldn't V_{\eta_{1}\eta_{2}\eta_{3}\eta_{4}} be non-zero for other combinations of indices? For example \eta_{1}=\eta_{4}=\uparrow, \eta_{2}=\eta_{3}=\downarrow should probably be allowed, since you're not creating or annihilating two of the same type of spin. Also...

Frustration usually means that there is an infinite degeneracy of the classical ground state. The random field effectively turns the system into that of a spin glass, where the interactions between spins will become effectively random. A spin glass has lots and lots of degenerate states, so I...

You do realize that your set up of masses couldn't exist in the "real world", don't you?

Thanks a lot for the reference! I'm not sure that it could be any more relevant.

Yes, those are the guys who came up with the idea. The reference for the original article is Physical Review E 50: 1645–1648., 1994. As for books, I can't think of any that contain a kind of exposition of the theory. There's a review article published somewhere, but I can't remember in which...

Yes, indeed. I'm asking for the maths that takes the Anderson to the Kondo hamiltonian more than the physics, I guess.

It seems cyrusabdollahi was taking thermodynamics to mean specifically equilibrium thermodynamics. The fluctuation theorem is indeed applicable to systems both close to and far away from equilibrium. It is similar to the Green-Kubo relations, but with the addition that it applies to situations...

A number of texts claim that the Hamiltonian for the Anderson model of a localised magnetic impurity contains the physics of the Kondo Hamiltonian. Does anyone have any suggestion for how to show this, or any reference that accounts for this?

And we still have posters in our department celebrating the first five years...

The first thing that springs to mind is that you'd get a better response in the Condensed Matter forum, and I suspect this thread will be moved there shortly. The second is that you need more references, and to make it clear where the theory comes from.