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visits member for 3 years, 5 months
seen Oct 18 at 14:37

Physics graduate, web developer. Graphic design enthusiast :D


Jan
25
comment Measuring background radiation
The water in the nuclear power plants has boron in it that absorb neutrons if I recall correctly ;)
Jan
13
comment Squashed 3-sphere?
Yeah, that was what I was thinking. It's not really intuitive. I would expect something that was more standard 3 sphere metric looking... But thanks nonetheless :)
Jan
13
comment Squashed 3-sphere?
Oh, so that's where all the similarity with warped AdS${}_3$ comes from. Just a warped sphere in a sense...
Jan
13
asked Squashed 3-sphere?
Jan
10
accepted Different definition of SL(2,R) algebra?
Jan
10
comment Different definition of SL(2,R) algebra?
I was just reading something about structure constants and thought that that might be the answer! So it is only difference in the given representation after all.
Jan
10
comment How do I correctly choose signs for a falling particle?
Have you tried setting up a coordinate system? That should help...
Jan
10
comment Different definition of SL(2,R) algebra?
Sorry, forgot about that, corrected it now.
Jan
10
asked Different definition of SL(2,R) algebra?
Jan
7
comment Energy dispersion in graphene
See this: en.wikipedia.org/wiki/Density_of_states It has basically all you need ;)
Jan
6
answered Energy dispersion in graphene
Jan
6
comment Energy dispersion in graphene
If I'm not mistaken, there are two carbon atoms per primitive cell, and each has 3 nearest neighbors, so that should be correct. For DoS you need the expression: $g_{2d}(E)=\frac{1}{A}\sum_k\delta(E-E(k))$ if I recall correctly. Then you assume that you have a large volume and go to continuous limit, from sum to integral. Then it's just solving the integral (transform the integral from $k$ to $E$ to integrate and that should be it)
Jan
6
comment Energy dispersion in graphene
Well you need to draw the crystal structure of graphene, then you can find the unit cell, primitive cell, all the info about Bravais lattice. Then you can see the number of nearest neighbors. For DoS you can search the google density of states for graphene, and 4th pdf has about this. Also look your literature: Kittle, Ashcroft Mermin... graphene is really popular and there is a lot of info on it.
Dec
28
comment Really nothing special when falling into a black hole?
If I remember correctly the bigger the black hole is, the tidal forces that the body feels are weaker, and the smaller it is they are stronger, but in all reality if you are falling in the black hole you are doomed one way or another :D
Dec
28
comment Warped AdS geometry
The firs link is forbidden, but I think that the TASI lectures will do. I need a definition what is warped AdS (AdS_3 to be exact), a bit about the symmetries (altho that follows from the symmetries of the AdS_3). The general info.
Dec
28
accepted Warped AdS geometry
Dec
27
asked Warped AdS geometry
Dec
16
comment What is a Nyquist edge?
Google? en.wikipedia.org/wiki/Nyquist_filter
Dec
14
comment Holographic principle and holograms
Ok, so technically I'm not wrong XD
Dec
14
comment Holographic principle and holograms
What interests me is: is it ok to say that we are living in a hologram (Susskind likes to say so if I recall correctly)? In my opinion these two are very different things (holographic principle and holograms). But people think they are somehow connected. Or am I wrong and they really are connected?