Recent content by Pacopag

That's great. Thanks.

That's great Bavid! Is there ANYTHING that can be done if the matrix is not of rank 1? Or is it the case that no such decomposition exists, even up to undetermined coefficients, if the rank is anything other than 1?

Hi. I'm wondering if anyone can point me to any information on techniques to decompose a matrix (actually a 3D matrix) into an outer product of vectors. Particularly, given M_{i,j,k}, I want to find vectors a_{i}, b_{i} and c_{i} such that M_{i,j,k} = a_{i}b_{i}c_{i} where the...

Hmmm. Interesting. I was finding that most "input functions" I tried gave solutions. But I can't seem to find some general condition telling us when there is a solution or not. The variable t represents time, and in this case it should be positive. But other than that there are no...

No problem. You don't have to apologize. I just thought that maybe someone would be all like "yeah, that means...blah blah...compact support...blah blah...and the supremum norm of f^-1 would have to be...blah blah...least upper bound...blah blah with transendality four... blah blah" and all...

Thank you for your replies. The function f(x) = e^x would do the trick, but then the equation is satisfied for ALL t. I'm particularly interested in cases where the equation is satisfied for discrete values of t. Think of it like this: The left hand side and right hand side are DIFFERENT...

Hi. Sorry I couldn't think of a more appropriate title for this thread. I'm doing some calculatons and I arrived at an equation with this form f(t')|_0^t = \int_0^t f(t')dt' I was just wondering if anyone as any insight into the interpretation of such an expression. All I can think...

No problem. Thanks for your help. I guess I just have to keep reading.

So if c is an operator, then I'm guessing that it may carry several eigenvalues. But I've never heard of a CFT with more than one central charge. Maybe I just haven't read far enough yet. Is there such thing as fractional or irrational central charges? Like, say, c=pi?

Sure. That helps a bunch. So when we say that a CFT has central charge of, say, c=2, do we really mean that the "eigenvalue" of c is 2?.

Hi. I'm trying to learn CFT on my own, and central charge seems to be a pretty important concept. It seems that I can only find mathematical definitions in terms of the stress-energy tensor, or the Virasoro algebra. I was wondering if someone could give me a physical interpretation of central...

Wow! That's an excellent answer. I wish I could buy you a beer for that one. Thanks very much.

what does "mixing under RG flow" mean? I'm trying to understand the language people use when they talk about RG flow. Here's what I understand: We have the RG flow equations governing the couplings' dependence on energy scale [tex]\mu {dg_i \over d\mu}=\beta(g_j)[\tex], and we can find the...

Hi. This isn't really a technical question, but here it goes. I'm filling out an application, and I have to indicate whether the conferences I have attended are institutional, national, or international. How do you distinguish these? From what I can tell, almost all conferences allow...

Yes. You are right. The second term in my action does not work.