Wednesday, July 11, 2012

Sunyaev-Zel'dovich effect

the thermal Sunyaev-Zel'dovich effect is usuall derived for Compton-interactions of the CMB photons with a thermal gas of electrons - is the assumption of thermality necessary?

bonus: what's happening if the electrons become relativistic?

extra bonus: can you express $i^{+i}\pm i^{-i}$ in terms of trigonometric functions?

Wednesday, July 4, 2012

non-trivial topology of the Universe

this week we have a guest post by Shaun Hotchkiss
(a fellow cosmologist and blogger at trenches of discovery)

if the universe was a torus with a radius less than the current particle horizon, what sort of characteristic signatures would we expect to see in the large scale structure and/or the CMB?

and for a change, a bonus question which tackles the sociology of science (also proposed by Shaun): what do you think is the reason why scientists are underrepresented in political institutions?