2 research outputs found
Coupling dark energy with Standard Model states
In this contribution one examines the coupling of dark energy to the gauge
fields, to neutrinos, and to the Higgs field. In the first case, one shows how
a putative evolution of the fundamental couplings of strong and weak
interactions via coupling to dark energy through a generalized Bekenstein-type
model may cause deviations on the statistical nuclear decay Rutherford-Soddy
law. Existing bounds for the weak interaction exclude any significant
deviation. For neutrinos, a perturbative approach is developed which allows for
considering viable varying mass neutrino models coupled to any
quintessence-type field. The generalized Chaplygin model is considered as an
example. For the coupling with the Higgs field one obtains an interesting
cosmological solution which includes the unification of dark energy and dark
matter.Comment: 16 pages, 2 figures. Based on a talk delivered by O.B. at DICE 2008,
From Quantum Mechanics through Complexity to Spacetime: the role of emergent
dynamical structures, 22nd - 26th September 2008, Castiglioncello, Ital
Tension between SN and BAO: current status and future forecasts
Using real and synthetic Type Ia SNe (SNeIa) and baryon acoustic oscillations
(BAO) data representing current observations forecasts, this paper investigates
the tension between those probes in the dark energy equation of state (EoS)
reconstruction considering the well known CPL model and Wang's low correlation
reformulation. In particular, here we present simulations of BAO data from both
the the radial and transverse directions. We also explore the influence of
priors on Omega_m and Omega_b on the tension issue, by considering 1-sigma
deviations in either one or both of them. Our results indicate that for some
priors there is no tension between a single dataset (either SNeIa or BAO) and
their combination (SNeIa+BAO). Our criterion to discern the existence of
tension (sigma-distance) is also useful to establish which is the dataset with
most constraining power; in this respect SNeIa and BAO data switch roles when
current and future data are considered, as forecasts predict and spectacular
quality improvement on BAO data. We also find that the results on the tension
are blind to the way the CPL model is addressed: there is a perfect match
between the original formulation and that by the low correlation optimized, but
the errors on the parameters are much narrower in all cases of our exhaustive
exploration, thus serving the purpose of stressing the convenience of this
reparametrization.Comment: 21 pages, under review in JCA