Wednesday, June 27, 2012

baryonic acoustic oscillations

in what way do BAOs work as a geometrical distance measurement? What happens to BAOs in nonlinear structure formation? What assumptions concerning biasing does one do?

bonus question: is there an intuitive argument why the BAOs get destroyed in nonlinear structure formation?

extra bonus: what's $\log_i(\sqrt[i]{i})$ with $i = \sqrt{-1}$

Wednesday, June 20, 2012

haloes of all sizes

what are the largest and smallest objects (a.k.a. dark matter haloes) that can form in a given cosmology? which processes determine their sizes?

bonus question: what's $\log_i(\mathrm{e})$ with $i=\sqrt{-1}$

Wednesday, June 13, 2012

static universe

would it be possible to construct a FLRW-cosmology with no time dependence? what would be needed for such a cosmology? what's a sensible starting point for constructing this cosmology? would the solution be stable?

bonus question: what's $|i!|$ with $i=\sqrt{-1}$?

Wednesday, June 6, 2012

gravitational lensing

what matter distribution generates a lensing effect where the lensing convergence is equal to the shear amplitude for any position?

bonus question: can the image of a lensed galaxy be rotated in gravitational lensing? if yes, under which circumstances?