MHV Vertices & Scattering Amplitudes in Gauge Theory

0:00 This is 3-3, 3-level amplitudes of the MHV Diagnons. Well, they are the connected instances about which you have heard more in Sprat install, and they also seem to compute the same starting amplitudes. It turns out that that can be understood, which has been in the paper by Gukov, Moko and Nijewski. Essentially, by studying the connected instantons and noticing that they have a fault when the instanton degenerates to intersecting lines. So this way, you can reduce the connected instanton just to an integral over the modulized space of intersecting lines. we can consider the disconnected instantons, which I have described here, and they have a call when the disconnected instantons intersect. So this way, the two transgressions lead to the same answer, and there is no contradiction, although we would want to understand this relation. I haven't said much about LUT essentially because, well, there has been a lot of progress in studying LUT amplitudes with increasing inspired areas. In particular, Cavallini is going to tell us more how to use MHV vertices to compute one LUT amplitudes. One point about this computation though is that it is done in Minkowski space and we would like to understand how to derive it from the Twister-Spring theory some computation with MHV vertices with the disconnected de-instantons in Twister space and that unfortunately hasn't been done yet and actually the situation is even a bit worse because it turns out that the Vista string has closed strings, which correspond to the optimally supersymmetric conformal supergravity. Let me just remind you its action, it's essentially the Y to N squared, so it's a force of the action. The gravitational have one located the first propagator, and these closed strings also come into the loop amplitudes, you cannot separate them out. So the Tracer-Spring theory, in the known formulation by Witten and Verkovic,

2:30 actually computes the loop amplitudes of n equals for cage theory coupled to n equals for conformal supergravity, which are the loop amplitudes which we would want for phenomenological interest. So there is a lot of work to be done by Twister string theory. So, let me compute. The M-H3 diagrams give a new way to compute the angular scaling altitudes that have been motivated from Twister space, and there is a Twister string theory which leads to them at C-level. You do not even understand how to study this Twister string theory at Wolf-level. However, in Minkowski space, the situation It turns out that you can use MHD vertices to compute the loop amplitudes not only in the maximally supersymmetric angle theory, but also in the less supersymmetric, like N equals 1 angle theory, and also the cut-constructible part of non-supersymmetric amplitudes. So, the open questions, the main ones, I would say, is to find the Christos-String theory, which does not contain some form of supergravity, And another one which will be of great interest for phenomenology is to generalize MHV vertices to non supersymmetric gauge series at Bulba level. Thank you. The optional extension that you used for the theme, is that you use it because it's the theme plus one, do you know the color of the extensions in the world? Well, it's essentially the only thing you can write down. You have an object which is the momentum PA dot, and you want to get from it something which has only one spinner index A, so the thing you can do is just contract the other index A dot with some operative momentum. So why? I think you do that they are the function that they exist and you know, modern constant feeling

5:00 Well, there has been a one thing that's true that crossover, burn and collaborators have have used a slightly different way to take amplitudes off-shell, where they essentially pick a constant light-like vector and they project an off-shell momentum along this light-like vector to make it on-shell. But this off-shell configuration is equivalent to the one here, up to scaling. And the scaling always drops out from MHP diagrams. So you can write down slightly different expressions but I haven't seen yet one which would lead to different expressions. One thing which you can do is, in twisted space, to try to do slightly different computations, like using slightly different open string propagator and see whether that leads to different offshore continuations. I don't think that, I'm not aware that much has been done in this direction, so, well the general law is that the conformal supergravity is not unitary because it has negative norm states, but that's a statement which has been around for many years I'm not aware of this statement from all this direction I'm going to continue to look at you and when you completed the flash-mash-mash-mash-mash-mash-glown-up module with a machinery of the HB, you used both channels two times to give zero I use both? of both channels to get zero. If I remember well, in curiosity in theory, each of these channels is zero without the mainstream. Do you know why this is happening? Well, you know, each of the individual diagrams is not the Gaussian rayon thing, so it can give you a different answer. Only the sum of all diagrams, which is the physical setting

7:30 It should lead to location where an answer, which is zero. No, no, it's actually not true. There is a choice of reference, and then it's just that each guy ran an answer. Okay. So, maybe that's the question. Why if you choose all the reference for an answer? It's not a way to use zero. It might be just the case that since we have so few particles, there is enough freedom. The freedom is one reference spinner, and if there are few particles, then this freedom might be enough to kill the diagrams. The estimate might be that in that case, we get the diagram advantage separately. You use some reference, one method would be in some direction, and one would be in a different direction. whereas what you're doing is more like all in the same direction which works for all of us Did we get the position? In this case, uh, let's thank you for joining us