Recent content by KarateMan

thanks everyone. malawi_glenn, your explanation made me realize the important point! although I have exactly copied that part from a textbook... thanks again.

I have questions about the infinitesimal Lorentz transformation. but specifically about index manipulations. \Lambda^{\mu}_{}_{\nu}=\delta^{\mu}_{\nu}+\delta\omega^{\mu}_{}_{\nu} where \delta\omega^{\mu}_{}_{\nu} << 1 as found in many textbooks, we substitute this into...

Thank you for such a quick reply! I will check it out. but your explanation helped a lot, CRGreathouse!

hi, I am writing a computer algorithm which descibes the change of choice. 1.your friend puts $10 in a box among three (there are three boxes) but you don't know which. 2.you choose one of them but do not open it. 3.your friend opens (eliminates) one of empty boxes i.e. if you choose...

Thank you malawi_glenn! I have finally understood it. It was much easier than I thought.

sorry, you cannot jump from the hyperlink above. make sure copy the last ")" as well.

Hi everyone. I am now learning the perturbation theory in QM. and I have encountered something that puzzles me. from http://en.wikipedia.org/wiki/Perturbation_theory_(quantum_mechanics ) says, "...Since the overall phase is not determined in quantum mechanics, without loss of...

I am only guessing. If you say I am wrong, that is simply because I am not that good yet. I found these concepts very difficult to organise in my head. I am trying to find the best way to understand the differential forms of degree TWO or higher. Regarding "topological invariant", does...

uh, it is hard to express in words, though. I will do my best. Algebra and topology are distinct mathematical concepts because they have their own definitions. We can develop mathematical theorems with each of those independently. When we talk about the differential forms of degree ZERO...

I have a quetion about the forms. When we say, "differential forms of degree one (or more)" rather than degree zero, the algebra is now mixed with topological properties. Am I correct? I am simply trying to find my way to understand this.

Thanks everyone. took me a while but I think I swallowed it!

I have a question about Lie subalgebra. They say "a Lie subalgebra is a much more CONSTRAINED structure than a subspace". Well, it seems subtle, and I find this very tricky to follow. Can anyone explain this with concrete examples? If my question is not clear, please tell me so, I will...

I would like to ask you about exterior derivative. I have found the exterior derivative very difficult to visualize. Does it have anything to do with the ordinary derivative of a scalar function? What I mean is that the ordinary differentiation is the rate of change of the scalar function...