Recent content by femtofranco

Hello, sorry about the delay, but I was trying your solution. Unfortunately, when I enter <<VectorAnalysis into a notebook, followed by the shift and enter, it responds "Get::nopen : Cannot open VectorAnalysis." I have gone into the program files and cannot seem to find the VectorAnalysis...

Hello, having usually used MatLab, I am just beginning to use Mathematica. I am having trouble locating packages, however. In particular, I'd like to download: http://reference.wolfram.com/mathematica/VectorAnalysis/tutorial/VectorAnalysis.html (Vector Analysis)...

Hello I am looking to learn about Lattice Gauge Theory. I am already understand the general theory, (that is, defining fermions and gauge fields on lattice sites and links, respectively), but am having trouble intuiting the results of such calculations. As an example, the following is a...

I have been reading around in general relativity, and see that, for Quantum Field Theory in Curved Spacetime, the notion of a preferred time coordinate comes up quite often (to distinguish positive frequencies). Why must the coordinate be 'preffered,' i.e. why must it be a consequence of the...

Thank you, both. The whole matter seems much clearer to me. And I must say, that was a lovely article.

Hello, I am reading up on QFT in curved spacetimes, and am aware that states of QFT's in such spacetimes, have, in general, no physically meaningful particle definitions. I was just hoping someone could clarify what is meant by "physically meaningful."

This is quite nifty, but let me make sure I understand this. To find the transformed x, you simply add the components of the vector K(x) to x. As such, the final form from your example would be: x^{c}\rightarrow (1 - \frac{i}{2}\omega_{ab}L^{ab})x^{c} We would then insert this into...

Hello, I was wondering, since gravitational waves carry energy-momentum, would it be possible to find them in regions where the components of the metric tensor vanish? That is to say, empty space (non-quantum) is described by a vanishing energy-momentum tensor - but then, if gravitational waves...

Hi, I'm also interested in QFT in Curved Spacetime, but am very new at it. Reading this, I am further behind than I thought. I tried to read that post you link to, sam, but I am not very comfortable with it. Looking at your first post here, you wrote: x^{a}\rightarrow x^{a} +...