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Centro de Astrofísica da Universidade do Porto

Fine-structure constant constraints on dark energy

C. J. A. P. Martins, A. M. M. Pinho

We use astrophysical and atomic clock tests of the stability of the fine-structure constant α , together with type Ia supernova and Hubble parameter data, to constrain the simplest class of dynamical dark energy models where the same degree of freedom is assumed to provide both the dark energy and (through a dimensionless coupling ζ to the electromagnetic sector) the α variation. We show how current data tightly constrain a combination of ζ and the dark energy equation of state w0 . At the 95% confidence level and marginalizing over w0 we find |ζ|<5×106 , with the atomic clock tests dominating the constraints. The forthcoming generation of high-resolution ultrastable spectrographs will enable significantly tighter constraints.

Observational cosmology, Modified theories of gravity, Determination of fundamental constants, Dark energy

Physical Review D
Volume 91, Page 103501
May 2015

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Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

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