Recent content by Morgoth

you have to take into assumption some stuff... For example you'll have to assume that the nuclei have constant density... and you'll have to assume that their shape is given (to be spherical)...

thanks for the rest information, however I can't get how the insertion of a Vector Boson instead of the (νe,e) can help in any way... I'm not trying to say that Fermi was right (of course nowadays the Bosons of WI have been observed, so even experimentally they are verified). I am trying to...

Well, I was looking at the beta decay of neutron, and I thought that the weak interaction can be seen in analogue to QED, where you have an electron that emits(or absorbs) a photon and gets scattered. In the same way, couldn't we say that a Neutron is scattered to a Proton (I see them as the...

Well I'm not sure about what I'm going to say, but I am open to corrections ^_^. it's not Higgs Boson that gives the masses... It is the Higgs Interaction with particles, that breaks the symmetry of electroweak theory and weak interaction bosons (W,Z) appear with mass while electromagnetic...

Well I am sure this is a lame question, but I am stuck over it for hours. I'm working on Bjorken, Drell book, and I'm trying to calculate the extreme relativistic differential cross section for electron-positron scattering. Well, I have evaluated the cross section up to my attachment's...

One more question, in case anyone knows... If you have an I: ds2= a (dθ2+sin2θ dφ2) you can show that a is not absorbable parameter if the below equation has no solution: Lξgαβ=∂gαβ/∂a where L is the operator of Lie Derivative... Is there an alternative way to show it?

One question on this, although it is not appropriate for a GR or SR topic. When we have our action, and we add the electromagnetic interaction field (the Fαβ) don't we impy that EM field is everywhere in our spacetime? Doesn't that imply that it does not propagate with a certain speed (c)?

the weirdest thing is that if the metric in variation is with indices up it appears with a minus sign...

Yes but from the Rieman Tensor I can evaluate the Ricci tensor and the scalar curvature. The same S.curvature would describe the same space. But the whole procedure is tough, tiring and of course might contain mistakes (when I tried it, just for the Riemann tensor I filled 3 pages and I was not...

1. yes they were given to me as part of the problem. they are what I know... One question was to show that I is indeed a killing vector, which I proved. 2. OK I will try this now...

Well my main questions are colored in red... Set of problem Let's suppose we have a metric gab(x) and the Killing vectors Ia ( Ia;k=0, gμαIμIα= 0) question Show that those killing vectors are the gradient of a Scalar field, and that it satisfies the equation IαRαβγρ=0 Show that the...

δ(√g)= (1/2√g) δg g=εabcdg0ag1bg2cg3d δg=...

The Riemann tensor is a tensor...Which means that if it vanishes in a Coordinate System, it will vanish in any others after a coord.transformation... But still what is the most obvious conformal form for a metric? I've seen that it needs to be written in the form: ds2= Φ(x,y) {dx2+dy2} of...

oops...yes it can't...that was my mistake... still =_= it's obviously in the simplest form

If you are given a metric gαβ and you are asked to find if it describes a flat space, is there any way to answer it without calculating the Riemman Tensor Rλμνσ? and how can I find for that given metric the coordinate transformation which brings it in conformal form? For example I'll give you...