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Centro de Astrofísica da Universidade do Porto
Fundamental Constants in an Accelerating Universe

Rodger I. Thompson
Steward Observatory, University of Arizona

It is now widely accepted that we live in a universe with an accelerating expansion. We can embrace the cosmological constant as the cause but then must confront the realization that all current calculations of the value of the constant are on the order of 50 magnitudes greater than its measured value. The most popular alternatives to the geometric view are cosmologies with rolling scalar fields as the source of the acceleration. Under the new physics assumption that the electromagnetic field is also coupled to the scalar field, the values of the fundamental constants such as the proton to electron mass ratio, mu, and the fine structure constant, alpha, are also predicted to roll with time. This talk looks at the impact of the measured values of the fundamental constant mu in the early universe on four different rolling scalar field cosmologies and the coupling constant of mu with the field. The observed limits on the variance of mu force either a limit on the variance of the equation of state parameter w to only a few percent from -1 or a value for the coupling constant much lower than its expected value. These findings are putting stringent constraints on the combination of new physics and alternative cosmologies and suggest that compliance with the values of the fundamental constants is an essential test for any proposed cosmology or new physics.

23 May 2012, 13:30

Centro de Astrofísica
Rua das Estrelas
4150-762 Porto

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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