相关论文: Electroweak Baryogenesis and the Expansion Rate of…
Radiation domination at the electroweak epoch is a simplifying assumption, but one for which there is no observational basis. Treating the expansion rate as a variable, I re-examine electroweak baryogenesis in various scenarios. At a first…
The usual sphaleron bound and the statement of the impossibility of baryon production at a second order phase transition or analytic cross-over are reformulated in the first part of the paper as requirements of the expansion rate of the…
In principle, the baryon asymmetry of the Universe can be generated at the electroweak phase transition but the experimental lower limit on the Higgs mass seems to rule out a Standard Model scenario. However, it has been shown recently that…
We describe a new mechanism for the generation of the baryon asymmetry of the universe during a first order electroweak phase transition. The mechanism requires the existence of two (or more) baryon number carrying scalar fields with masses…
In this study we examine post-inflationary cosmologies dominated by a scalar field with the equation of state: p_phi=w_phi rho_phi (0 leq w_phi leq 1) in order to facilitate baryogenesis at the electroweak scale. We take a more conventional…
We reanalyse the sphaleron bound of electroweak baryogenesis when allowing deviations to the Friedmann equation. These modifications are well motivated in the context of brane cosmology where they appear without being in conflict with major…
A cosmological pseudoscalar field coupled to hypercharge topological number density can exponentially amplify hyperelectric and hypermagnetic fields while coherently rolling or oscillating, leading to the formation of a time-dependent…
We propose a mechanism for baryogenesis in which the baryon asymmetry is generated as an equilibrium response of weak sphalerons in a region where electroweak sphaleron transitions remain unsuppressed, $h/T\lesssim 1$. A nonzero equilibrium…
Scalar fields can play a dominant role in the dynamics of the Universe until shortly before nucleosynthesis. Examples are provided by domination by a kinetic mode of a scalar field, which may be both the inflaton and the late time…
We discuss the possibility of generating the baryon asymmetry of the Universe when the temperature of the Universe is much below the electroweak scale. In our model the evaporation of primordial black holes or the decay of massive particles…
Existence and properties of the electroweak phase transition in the early universe depend strongly on the mass of the Higgs scalar M_H. There is presumably no true symmetry restoration at high temperature. Nevertheless, a first order phase…
We propose a new alternative for baryogenesis which resolves a number of the problems associated with GUT and electroweak scenarios, and which may allow baryogenesis even in modest extensions of the standard model. If the universe never…
For successful electroweak baryogenesis to take place through the sphaleron process the universe needs to undergo a strong first order cosmological phase transition. While it does not occur in the Standard Model it becomes possible in the…
The presence of a primordial magnetic field in the early universe affects the dynamic of the electroweak phase transition enhancing its strength. This effect may enlarge the window for electroweak baryogenesis in the minimal supersymmetric…
The origin of the matter-antimatter asymmetry remains one of the most fundamental problems of cosmology. In this talk I present a novel scenario for baryogenesis at the electroweak scale, without the need for a first order phase transition.…
The generation of the observed baryon asymmetry may have taken place during the electroweak phase transition, thus involving physics testable at LHC, a scenario dubbed electroweak baryogenesis. In this paper we point out that the magnetic…
If stable electroweak strings are copiously produced during the electroweak phase transition, they may contribute significantly to the presently observed baryon to entropy ratio of the universe. This analysis establishes the feasibility of…
We investigate scenarios in which electroweak baryogenesis can occur during an exotic stage of electroweak symmetry breaking in the early Universe. This transition is driven by the expectation value of a new electroweak scalar instead of…
It now seems plausible that the observed baryon asymmetry may have been produced at the electroweak phase transition. We review the considerations which lead to this conclusion, focusing on the obstacles to making reliable estimates. These…
In this paper, we investigate the generation of the baryon asymmetry of the universe during the first-order electroweak phase transition. We first study the generation of the helical magnetic field in the framework of the standard model…