## 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 $i = \sqrt{-1}$

1. Concerning the bonus question: first, we can write $\log_\mathrm{i} \sqrt[\mathrm{i}]{\mathrm{i}}=\log_\mathrm{i} \mathrm{i}^{1/\mathrm{i}}=\log_\mathrm{i} \mathrm{i}^{-\mathrm{i}}$. Thus, we search a number $x$ for which $\mathrm{i}^x=\mathrm{i}^{-\mathrm{i}}$. Obviously, this is $x=-\mathrm{i}$ and thus $\log_\mathrm{i} \sqrt[\mathrm{i}]{\mathrm{i}}=-\mathrm{i}$.