Physicists propose mechanism that explains the origins of both dark matter and 'normal' matter


December 10, 2010 by Lisa Zyga Enlarge






(PhysOrg.com) -- Through precise cosmological measurements, scientists know that about 4.6% of the energy of the Universe is made of baryonic matter (normal atoms), about 23% is made of dark matter, and the remaining 72% or so is dark energy.


Scientists also know that almost all the baryonic matter in the observable Universe is matter (with a positive baryon charge) rather than antimatter (with a negative baryon charge).


But exactly why this matter and energy came to be this way is still an open question.


In a recent study, physicists have proposed a new mechanism that can generate both the baryon asymmetry and the dark matter density of the Universe simultaneously.



copyright - credits :




No evidence of time before Big Bang.

Published online 10 December 2010 | Nature | doi:10.1038/news.2010.665


Latest research deflates the idea that the Universe cycles for eternity.


Edwin Cartlidge

Circular ripples in the cosmic microwave background have been making waves with theoreticians.



Our view of the early Universe may be full of mysterious circles — and even triangles — but that doesn't mean we're seeing evidence of events that took place before the Big Bang.


So says a trio of papers taking aim at a recent claim that concentric rings of uniform temperature within the cosmic microwave background — the radiation left over from the Big Bang — might, in fact, be the signatures of black holes colliding in a previous cosmic 'aeon' that existed before our Universe.



Dark Matter Halo



copyright - credits : http://www.nature.com/news/2010/101210/full/news.2010.665...