Recent content by Shakthi

:cry::confused::rolleyes: Someone please help . . .

I'm stuck with calculating g and p for Eu(3+). The outtermost orbitals in Eu is 4f7 5s2 5p6 6s2. Eu(3+) has 4f6 as the last orbital. Thus, S = 3, L = 3 and J = 0 since J = L - S here. How do I calculate g (using the formula given above) and then p. (p = g[S(S+1)]). The experimental...

I'm back to square one here. I was reading about Supersymmetry and basic Group Theory. I need some clarifications. A proper and orthochronous Poincare transformation excludes space inversion and time inversion, right? Can this group (proper and orthrochronous Poincare group) have...

Actually, I wanted to ask about Casimirs of the Poincare Group, the Lorentz Group and those of SUSY Algebra. I am kind of lost in this topic. How do we find the Casimirs for a particular group (for the Poincare Group in particular)? Is there any restriction for the number of Casimirs for a...

Back again... What exactly are Casimirs? Why do we need them and why are we studying them?

This brings up another question. what is meant by 'orthocronus'? I read that the first element of \Lambda is of consequence when dividing the Lorentz Group into four different classes. And the restricted Lorentz Group, namely the Proper Orthrocronus Group is the one mapped to SL(2,C) to bring in...

Now, I get it. It sounds similar to what we do in Small Oscillations in Classical Mechanics. The 6 dimensions here refer to the degrees of freedom and not the co-ordinates, right?

Thanks for the reply. Sorry I forgot about the 4-vector of the Poincare Group. I am still confused as to why we need a 6 dimensional space while we need just 4 co-ordinates to specify the Lorentz Transformation. Wouldn't a 4-D Space be enough?

One more doubt: I read that the Lorentz group requires a 6-dimensional space. Does that mean it needs 6 real parameters to be specified? Do those six parameters come from the 3 rotations and 3 boosts? How do the boosts contribute to these real parameters if they do not form a group...

Thanks a lot friends :smile: The information really helped me. Thanks again.

Thanks again. Why do we use five-by-five matrices to represent the generators of Poincare Group while the generators of Lorentz Group are represented by 4-by-4 matrices?

Thank you very much. Should I use the same method for representing translations too?

I'm new here and I have checked the FAQs. I'm not sure if this question has been posted before. This may actually be a silly question. Why do we study Lorentz and Poincare Groups? I have studied a bit of the theory but was wondering what exactly are we talking about when we study the...