Experimental signatures of non-standard pre-BBN cosmologies

ar X iv : 0 90 7 . 16 94 v 1 [ he p - ph ] 9 J ul 2 00 9 Experimental signatures of non - standard pre - BBN cosmologies ∗

If detected, dark matter particles, such as WIMPs and sterile neutrinos, will be the earliest relics we can study, the first coming from before Big Bang Nucleosynthesis, an epoch from which we have no data so far. Here we discuss how different pre-BBN cosmological models affect the properties of these particles, and how these properties could thus allow to determine the evolution of the Univers...

Cdm Abundance in Non-standard Cosmologies

The relic density of a cold dark matter (CDM) candidate is calculated in the context of three non-standard cosmological scenaria and its value is compared with the one obtained in the standard regime. In particular, we consider the decoupling of the CDM particle during: (i) A decaying-particle dominated phase or (ii) a kinetic-energy dominated phase or (iii) the decay of a massive particle unde...

Neutralino Relic Density Enhancement in Non-standard Cosmologies

The thermal relic abundance of species critically depends on the assumed underlying cosmological model. In the case of neutralinos, freeze-out takes place long before Big Bang Nucleosynthesis, which provides the strongest constraint on the evolution of the Hubble parameter in the Early Universe. We show that non-standard cosmologies, such as models featuring a quintessential scalar field or pri...

Transitive Signatures Based on Non-adaptive Standard Signatures

Transitive signature, motivated by signing vertices and edges of a dynamically growing, transitively closed graph, was first proposed by Micali and Rivest. The general designing paradigm proposed there involved a underlying standard signature scheme, which is required to be existentially unforgeable against adaptive chosen message attacks. We show that the requirement for the underlying signatu...

Synthesis of CNO elements in standard BBN