Recent content by alphaone

Hi, I have been wondering why we can consider d(phi)/dt when we are in Schrödinger picture (phi is just the usual scalar field here). Isn't this 0 as operators do not depend on time in this picture? However then how does it make sense to talk about the conjugate momentum in this picture which...

Could somebody please tell me a workable definition of the term "chiral theory" , and also explain its significance? As far as I know, in a chiral theory not all the fermions obtain a mass but whether this is a definition or a derived result is not clear to me. Thanks in advance

Hi I have a question concerning the anticommuting variable theta of the superspace manifold: For a proof of some renormalisation theorems I have seen the author make use of the transformation properties of theta under the internal U_R(1) symmetry i.e. he said theta -> exp(-i alpha)*theta ,under...

If my question is inclear please let me know, because I really would like to know the answer of this question.

Thanks for the reply. I see what you are saying but now my quetion is: In the case of delta(m-n)*A=delta(m-n)*f(m,n) is it valid to deduce A=lim(m->n)f(m,n) or is it only valid to deduce A=f(m,m)?

Thanks for the reply. Sorry the way I phrased the question was really stupid. Obviously if A and B are const then A=B, but for the case I am interested we have A=const and B=f(m,n). Now my quesion should have been: If we have delta(m-n)*A=delta(m-n)*f(m,n) then in a famous paper a nobel...

Hi I am not a mathematician so my question might be silly. I really came across it in physics but I think it is purely mathematical: I came across an equation of the form: delta(m-n)*A= delta(m-n)*B my question is now for what cases can I conclude A=B? Does this only hold for m=n, or can I...

I now know why we need Q|0>=0 and what it means, but could somebody please tell me where to find the theorem of Sidney Coleman samalkhaiat was talking about. Thanks in advance

Figured this out myself already, so no reply needed.

I think I figured it out myself: Any symmetry transformation can be represented by either a unitary operator U or an antiunitary operator A acting on the space of states, i.e. U|phi> is the transformed state(for the case of a unitary operator) now if I am not mistaken we can write U =...

Hi, I have done classical symmetry breaking and now want to understand the quantum one. I have seen the statement that the symmetry is broken if and only if Q|0> not 0. Where |0> is the vacuum and Q is the associated charge of the broken symmetry. Why does this imply symmetry breaking? The way...

Hi, I recently saw an author make the following statement: If the symmetry leaves the 1-particle states invariant then its associated charge Q acts on the 1-particle states |p> such that Q|p> = 0 This statement is nontrivial to me, so if anybody could show me how it works please let me know.

Could you also name a reference where I can find a proof of the Coleman theorem? Thanks in advance

Thanks for the relpy. That result amazes me and I will definitely look up the theorem! Could you elaborate on what you mean by saying that the symmetry is manifest? Under what conditions can I assume Q|0> = 0 ? Please let me know.

Hi, thanks for the reply. I see what you are saying: In Minkowski t is timelike coordinate so t=const is spacelike surface. Then in Schwarzschild r is timelike coordinate inside the horizon so r=const is spacelike surface there, I see that now, thanks. Actually I do not find your r=const...