Thanks Trimok for clearing that up :) As mentioned on phys stackexchange, I would like to understand this, since GSW say in the appendix that getting 7.A.17 is possible from 7.A.12 and 7.A.22... :)
Hi fzero,
Thanks for your answer but I'm not sure I understand it in the context of the equations above. Would you be so could to make it more precise w.r.t. the formulae I used above. That would be very nice since i'm banging my head against this for a while now. Moreover, this point is...
I'm reading through chapter 7 of Green-Schwarz-Witten and I have a problem with the derivation of the M-tachyon correlation function. Basically I'm trying to get 7.A.17 from 7.A.12 and eq 7.A.22 in the appendix of the first volume.
Basically I want to prove...
Hi guys,
one question in this growing amplitude business that i don't understand. Usually one says that conformal field theories do not have any non-trivial scattering amplitudes because one cannot define asymptotic states. But say we consider now N=4 Super Yang Mills and moreover treelevel...
Hi and thanks for your answer. Ok, i just realize i have been too vague.
Acutally my expressions are of the type
MP[X,a_1]...MP[X,a_{2n}] where MP is the Minkowski scalar product. Some of the a_n might be the some. This can be replaced in my case (under an integral over X) by...
Hi guys,
i have expressions of the type (X*a)(X*b). I want replace this by X^2(a*b).
So i tried building a block which does nothing but
%//.(X*a_)(X*b_)->X^2(a*b).
However, this works only if a is distinct from b. If a and b are equal if HAVE to use the replacement command...
Ah, thanks for the explanation. One more question about this:
So coming back to the numerator, i could rewrite is in terms of a four-vector product as:
\langle a |L|b]^2 = (2q\cdot L )^2
where q is a four-vector build from the spinors \langle a| and |b].
Under the integral sign i could...
Hi and thanks for your reply. Look for instance at hep-th/0612007. They never do the integrals (they reduce them to scalar integrals using PV) but i was wondering how to do them without reducing them.
Look for instance at eq (3.9). If one is given such a type of integral but has no idea about...
Hi! Thanks for your reply!
I understand how to treat these integrals if the numerator of the integrand is expressed in terms of four-vectors. But how do I proceed if the numerator is written in the spinor bra-ket language above? I don't really know how to handle these expressions if the loop...
Hi guys,
i'm looking at one-loop calculations in terms of helicity spinor (basically a paper by Brandhuber, Travglini and others) language but i have no idea how to integrate them :)
For instance
\int FeynParam\int d^D L \frac{\langle a|L|b]^2}{(L^2-\Delta^2)^3}
How would I do...
Hi guys,
I have to brush up my knowledge about self-dual Yang Mills and I'm reading an ancient paper by Yang about it...and of course I'm stuck...although Yang writes 'it is easy to see that'...
Ok, so the self-duality condition of the YM field strength tensor is defined as...
Thank you for your answer! That is a nice way to understand this! From the book however I have the impression that the conclusion is much simpler to get and follows 'for free' from the invariance statements. But thanks a lot anyways!
earth2
P.s. you were right, the \sim should be an...