“…One way of studying the nature of dark energy is through the observational data. There are many model-independent studies on the nature of dark energy by using the observational data [10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39]. In particular, one usually parameterizes the energy density Ω φ (z) or the equation of state parameter w(z) of dark energy.…”