منابع مشابه
Dynamics of K-essence
There are a number of mathematical theorems in the literature on the dynamics of cosmological models with accelerated expansion driven by a positive cosmological constant Λ or a nonlinear scalar field with potential V (quintessence) which do not assume homogeneity and isotropy from the beginning. The aim of this paper is to generalize these results to the case of k-essence models which are defi...
متن کاملReconstructing K-essence
We present a model independent method of reconstructing the Lagrangian for the k-essence field driving the present acceleration of the universe. We consider the simplest k-essence model for which the potential is constant. Later we use three parametrizations for the Hubble parameter H(z), consistent with recent the SN1a data, to yield the Lagrangian F . Our reconstruction program does not gener...
متن کاملAtypical k-essence cosmologies
We analyze the implications of having a divergent speed of sound in k-essence cosmological models. We first study a known theory of that kind, for which the Lagrangian density depends linearly on the time derivative of the k-field. We show that consistency requires that the potential of the k-field be of the inverse square form. Then, we review the known result that the corresponding power-law ...
متن کاملThe Algebraic Essence of K-Rep
The modal description logic AEA:/Cboth constitutes a promising frame-work for reasoning about actions andallows for the formalization of severalnon-first-order aspects of KR systems based on DLs. However, other non-monotonic features of DL-based KRsystems, in particular role and conceptclosure inside the knowledgebase, lackan intuitive formalization in this m...
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ژورنال
عنوان ژورنال: Classical and Quantum Gravity
سال: 2006
ISSN: 0264-9381,1361-6382
DOI: 10.1088/0264-9381/23/5/008