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Centro de Astrofísica da Universidade do Porto

Thermodynamics of cosmic defect network evolution

P. P. Avelino, L. Sousa

We show that simple thermodynamic conditions determine, to a great extent, the equation of state and dynamics of cosmic defects of arbitrary dimensionality. We use these conditions to provide a more direct derivation of the velocity-dependent one-scale (VOS) model for the macroscopic dynamics of topological defects of arbitrary dimensionality in a (N +1 )-dimensional homogeneous and isotropic universe. We parametrize the modifications to the VOS model associated with the interaction of the topological defects with other fields, including, in particular, a new dynamical degree of freedom associated with the variation of the mass per unit p -area of the defects, and we compute the corresponding scaling solutions. The observational impact of this new dynamical degree of freedom is also briefly discussed.

Physical Review D
Volume 93
January 2016

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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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