Tuesday, January 14, 2014

Amateur Cosmologist: Two Puzzles

Most versions of the Lambda-CDM (cosmological constant plus cold dark matter) predict that dark matter concentration should peak strongly in the centers of galaxy clusters - forming a so-called cusp. Puzzle #1: Actual distributions seem to be cuspless and rounded. Why so?

The hot intra-cluster gas that makes up most of their normal matter mass radiates due to ion collisions (mean free path - l light year). Densities are near the centers so collisions are more frequent, more energy is radiated, and the gas cools faster. This should result in so-called cooling flows as hotter outer gas moves in to take the place of the now cooler gas, some of which should form neutral atoms and ultimately, stars. Puzzle #2: Such flows appear absent. Why?

Your amateur cosmologer has his crackpot idea of the year.

Dark matter is presumed to be composed more or less equally of darkons and anti-darkons, which, on those odd occasions on which they interact, annihilate. If the annihilation cross section is higher than expected, could that smooth out cusps? Could the energy released reheat central baryonic gas?

Just asking.