energy injection, spectral extraction

Padmanabhan (LBL) gave the astro seminar on the consequences of dark-matter annihilation on the CMB. He showed that the energy injection can extend the recombination epoch and reduce the observed power on small scales. It is almost exactly degenerate with the slope of the primordial perturbation spectrum, so if you marginalize over energy injection at redshift 1000, you find that even WMAP doesn't say anything interesting about the tilt of the power spectrum (at least if you allow energy injections that are large like in these new Sommerfeld-enhanced scenarios).

Bolton (Hawaii) and I discussed optimal spectral extraction. Bolton and Schlegel have taken this to a new level, working out optimal methods even in the face of extremely non-trivial trace, and wavelelengh-dependent resolution. He also worked out (maybe for the first time) a truly geometry-independent meaning of the word "resolution" for a spectrograph or imager (it depends not on the size of the PSF directly, but only indirectly through correlations in the sensitivities of independent pixels).

No comments:

Post a Comment