相关论文: Turning Around the Sphaleron Bound: Electroweak Ba…
The standard requirement for the production of baryons at the electroweak phase transition, that the phase transition be first order and the sphaleron bound be satisfied, is predicated on the assumption of a radiation dominated universe at…
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…
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…
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 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…
We present a novel scenario for baryogenesis in a hybrid inflation model at the electroweak scale, in which the Standard Model Higgs field triggers the end of inflation. One of the conditions for successful baryogenesis, the departure from…
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…
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…
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.…
We study the possibility of relaxing the cosmological bound on the Higgs mass coming from the requirement of non-erasure of the baryon asymmetry by sphalerons. After reviewing the Standard Model case we obtain this bound in two extensions…
I describe a new way for baryogenesis to proceed, which evades many of the problems of GUT and electroweak scenarios. If the reheat temperature after inflation is below the electroweak scale, neither GUT baryon production nor traditional…
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…
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…
We calculate the electroweak sphaleron rates in the reduced minimal 3-3-1 (RM331) model. In the context of the early Universe, this model undergoes a sequence of two first-order phase transitions, $SU(3) \rightarrow SU(2)$ at the TeV scale…
The realisation that the electroweak anomaly can induce significant baryon number violation at high temperature and that the standard models of particle physics and cosmology contain all the ingredients needed for baryogenesis has led to…
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…
We investigate whether baryogenesis is possible at a second order electroweak phase transition. We find that under rather general conditions, the departure from thermal equilibrium is suppressed by the expansion rate of the Universe, and…
We consider the presence of cosmic string induced density fluctuations in the universe at temperatures below the electroweak phase transition temperature. Resulting temperature fluctuations can restore the electroweak symmetry locally,…
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…