On the stability of fundamental couplings in the GalaxyS. M. João, C. J. A. P. Martins, I. S. A. B. Mota, P. M. T. VianezAbstractAstrophysical tests of the stability of Nature's fundamental couplings are a key probe of the standard paradigms in fundamental physics and cosmology. In this report we discuss updated constraints on the stability of the fine-structure constant α   and the proton-to-electron mass ratio μ=mp/me$μ=mp/me$ within the Galaxy. We revisit and improve upon the analysis by Truppe et al. [1] by allowing for the possibility of simultaneous variations of both couplings and also by combining them with the recent measurements by Levshakov et al. [2]. By considering representative unification scenarios we find no evidence for variations of α at the 0.4 ppm level, and of μ at the 0.6 ppm level; if one uses the [2] bound on μ as a prior, the α bound is improved to 0.1 ppm. We also highlight how these measurements can constrain (and discriminate among) several fundamental physics paradigms.KeywordsAstrophysical observation, Fundamental couplings, Unification scenariosPhysics Letters BVolume 749, Page 389October 2015 >> PDF>> ADS>> DOI

# 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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