K-essence and tachyons in braneworld cosmology
We investigate a k-essence field localized on the brane evolving linearly with the cosmological time for some kinetic functions and consider the atypical k-essence model for linear and nonlinear k-fields in FriedmannRobertsonWalker (FRW) cosmology. In the former case the k-field is driven by an inve...
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| Autores principales: | , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_02182718_v20_n9_p1705_Chimento |
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| Sumario: | We investigate a k-essence field localized on the brane evolving linearly with the cosmological time for some kinetic functions and consider the atypical k-essence model for linear and nonlinear k-fields in FriedmannRobertsonWalker (FRW) cosmology. In the former case the k-field is driven by an inverse quadratic polynomial potential and the solutions exhibit several different behaviors which include expanding, contracting and bouncing universes as well as a model with a finite time span, some of them ending in a big crunch or a big rip. In the latter case we find the potential and show that the atypical k-essence model is dynamically incomplete. Particularly, by selecting the extended tachyonic kinetic functions we analyze the high and low energy limits of our model, obtaining the nearly power-law solution. We introduce a tachyon field with negative energy density and show that the universe evolves between two singularities. © 2011 World Scientific Publishing Company. |
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