217 reputation
18
bio website jstotero.com
location Rome, Italy
age 28
visits member for 3 years, 5 months
seen Nov 10 at 8:16

Jan
14
comment Interpretation of the Random Schrödinger Equation
@RonMaimon:Thx for your reference, I already studied the original paper from Parisi and Sourlas, and reviewed the supersymmetric approach to stochastic problems on Zinn-Justin's book, and some Gozzi's papers. I'll take a look at Oz's article :)
Dec
10
comment Gaussian Integrals : Functional determinant expressed as a trace
@Qmechanic : can you suggest me some reference about the trace regularization?
Dec
9
comment A certain $\cal{N}=2$ superconformal theory (or is it?)
Great insight :) Thanks
Dec
9
comment Interpretation of the Random Schrödinger Equation
@Ron Maimon : Actually this is a very interesting answer. Could you provide me some references about the supersymmetric approach to obtain mean quantities? I am currently studying a random electromagnetic system, and after attacking it with the replica-trick, I'm willing to try the more rigorous SUSY formulation, but I cannot find more detalied information on it.
Dec
8
comment Gaussian Integrals : Functional determinant expressed as a trace
@Vibert : Actualy expanding the $\log$ was my idea. Provided idk how to manage an expansion over "abstract operators", I would like to project the whole $\mathrm{Tr} \log [..]$ over $x$ or $k$, and then expand the projected logarithm. But how exactly does a $\mathrm{Tr}$ projection work?
Dec
8
comment Gaussian Integrals : Functional determinant expressed as a trace
Symmetric matrix, sorry, I wrote it wrong. In the full calculation I have to do, $\varphi$ is a real field and $\psi$ is a grassman-odd variable.
Nov
5
comment Field theory:functional derivative involving Fourier Transform
Yes I know you can do it by glance, but I did every step just to be sure something pedantic was not happening here :). The next step in my work here was to integrate the above derivative, notice it is just an inverse fourier transform (due to the supposed positive exponent), and then use the convolution theorem to move back to the real space. Actually, this is not a real problem because I found a much faster solution that avoids me this calculation and produces me the right result in zero time :) Thx, I'll set your answer as right, given it's a good example of a direct calculation :)
Oct
3
comment Field theory:functional derivative involving Fourier Transform
knives : thanks :) I fixed it :)
Oct
3
comment Field theory:functional derivative involving Fourier Transform
Qmechanic : It's a private report, so it's not published ATM :)
Oct
3
comment Field theory:functional derivative involving Fourier Transform
Vladimir : I am perfectly in agree with you, this can be extremely misleading sometimes, and, when possible, I try to use the bar notation for the Fourier Transform. Here I'm reporting the exact notation used in the work I'm studying :)
Oct
2
comment Field theory:functional derivative involving Fourier Transform
Yes it could make a great difference in this case... but applying the definition of functional derivative, the delta should be $/delta(k-k\prime)$ (the first one is the silent variable, the second one is the actual variable of the resulting derivative)... how do you obtain the inverted delta
Oct
2
comment Field theory:functional derivative involving Fourier Transform
Wait, maybe I got it... it seems I am performing a direct Fourier Transform of the $\delta(k)$, and this should produces me the complex coniugate of its anti-transform, am I right?
Oct
2
comment Field theory:functional derivative involving Fourier Transform
Yes I am sure I'm using the same definition... from the details in the paper it seems they obtain a different delta function $\delta(k+k\prime)$ when computing the derivative of log in k... but it does not make any sense! :)
Oct
1
comment Quantum Field Theory: why fields are equal to zero on the boundary?
In my case, I'm using field theory to study fluctuations on the sound wave propagation speed (phonons) inside a disordered solid. It yields the SCBA approximation, as depicted by W. Schirmacher. Following the calculations, it seems clear that in some places he exploits the $\varphi=0$ assumption, and I think that it's exactly one of the "finite domain of interest" case. Thx for your answer. Anyway, as this could be a quite interesting topic, I'll leave it open a little more, and set your answer as correct if there won't be other answers :)
Sep
30
comment Help With Difficult Deductive Proof
in equation (2) you mean that X and Y are function of u and v or they are simply multiplied?
Jun
12
comment Neutral Pion Decay
Would you write your comment to answer, so I can accept it? Thx
Sep
10
comment Neutral Pion Decay
Edited, thanks :)