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Centro de Astrofísica da Universidade do Porto

CMB constraints on spatial variations of the vacuum energy density

P. P. Avelino, A. Canavezes, J. P. M. de Carvalho, C. J. A. P. Martins

In a recent article, a simple `spherical bubble' toy model for a spatially varying vacuum energy density was introduced, and type Ia supernovae data was used to constrain it. Here we generalize the model to allow for the fact that we may not necessarily be at the center of a region with a given set of cosmological parameters, and discuss the constraints on these models coming from cosmic microwave background radiation data. We find tight constraints on possible spatial variations of the vacuum energy density for any significant deviations from the center of the bubble and we comment on the relevance of our results.

Astroparticle Physics
Volume 17, Page 367
June 2002

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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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