Reconstructing K-essence
نویسنده
چکیده
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 generate any physically realistic Lagrangian for models that allow phantom crossing, whereas models without phantom crossing, yield well behaved Lagrangians. PACS numbers: 98.80.-k, 98.80.Es, 98.70.Vc
منابع مشابه
Near optimal bound of orthogonal matching pursuit using restricted isometric constant
As a paradigm for reconstructing sparse signals using a set of under sampled measurements, compressed sensing has received much attention in recent years. In identifying the sufficient condition under which the perfect recovery of sparse signals is ensured, a property of the sensing matrix referred to as the restricted isometry property (RIP) is popularly employed. In this article, we propose t...
متن کاملNo-go theorem for k-essence dark energy.
We demonstrate that if k-essence can solve the coincidence problem and play the role of dark energy in the Universe, the fluctuations of the field have to propagate superluminally at some stage. We argue that this implies that successful k-essence models violate causality. It is not possible to define a time ordered succession of events in a Lorentz invariant way. Therefore, k-essence cannot ar...
متن کاملA no-go theorem for k-essence dark energy
We demonstrate that if k-essence can solve the coincidence problem and play the role of dark energy in the Universe, the fluctuations of the field have to propagate superluminally at some stage. We argue that this implies that successful k-essence models violate causality. It is not possible to define a time ordered succession of events in a Lorentz invariant way. Therefore, k-essence cannot ar...
متن کاملParametrization of K-essence and Its Kinetic Term
We construct the non-canonical kinetic term of a k-essence field directly from the effective equation of state function wk(z), which describes the properties of the dark energy. Adopting the usual parametrizations of equation of state we numerically reproduce the shape of the non-canonical kinetic term and discuss some features of the constructed form of k-essence.
متن کاملHolographic reconstruction of the k-essence and dilaton models
We propose an holographic k-essence and dilaton models of dark energy. The correspondence between the k-essence and dilaton energy densities with the holographic density, allows the reconstruction of the potential and the fields for the k-essence and dilaton models in flat FRW background. For the proposed infrared cut-off the reconstruction was made for the two cases of the constant α: for α < ...
متن کامل