## [astro-ph/0505253] Parametrization of Quintessence and Its Potential

 Authors: Zong-Kuan Guo, Nobuyoshi Ohta, Yuan-Zhong Zhang Abstract: We develop a theoretical method of constructing the quintessence potential directly from the effective equation of state function $w(z)$, which describes the properties of the dark energy. We apply our method to four parametrizations of equation of state parameter and discuss the general features of the resulting potentials. In particular, it is shown that the constructed quintessence potentials are all in the form of a runaway type. [PDF]  [PS]  [BibTex]  [Bookmark]

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Leandros Perivolaropoulos
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### [astro-ph/0505253] Parametrization of Quintessence and Its P

It is well known that minimally coupled quintessence potentials can not be reconstructed when w(z) crosses the line w=-1. Yet this paper uses arbitrary w(z) parametrizations and obtains potential reconstructions.

It seems that this is because the authors have not fitted their parametrizations to the SnIa data but instead they have used arbitrary parameter values which do not lead to crossing of the w=-1 line.