combine the transversal BAO data with the CMB shift parameter information defined as $R \equiv \sqrt{\Omega_m H_0^2} \,\, r_s(z_{rec})$, where $r_s(z_{rec})$ is the comoving sound horizon at recombination. In our case, we use the shift parameter given by the Planck collaboration $R = 1.7407 \pm 0.0094$ [@Wang2013].

Assuming the sound horizon value obtained by WMAP9 [@wmap9], $r_s(z_{drag}) = 106.61 \pm 3.47$ Mpc/h, jointly to the Planck measurement of the shift parameter[^3], we constrain the $\Omega_m$ and w$_0$ for the wCDM model. Thus, the best-fit corresponds to $\Omega_m= 0.31 \pm 0.02$ and w$_0 = -0.92 \pm 0.06$ for the wCDM model, while for w$(a)$CDM we found w$_0= -0.87\pm 0.13$ and w$_a= -0.15\pm 0.32$. The confidence level contours for $\Omega_m-\mbox{\rm w}_0$ for wCDM model and w$_0-$w$_a$ for w$(a)$CDM model can be seen in figure \[contours\].

![One and two $\sigma$ confidence level contours of the $\Omega_m-{\mbox w}_0$ and ${\mbox w}_0-{\mbox w}_a$ planes for the wCDM and w$(a)$CDM models, respectively.[]{data-label="contours"}](figure5a.pdf "fig:"){width="56.00000%"} ![One and two $\sigma$ confidence level contours of the $\Omega_m-{\mbox w}_0$ and ${\mbox w}_0-{\mbox w}_a$ planes for the wCDM and w$(a)$CDM models, respectively.[]{data-label="contours"}](figure5b.pdf "fig:"){width="56.00000%"}

\[sec5\] Conclusions and Final Remarks
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Following the same quasi model-independent approach used in the refs. [@Carvalho; @Alcaniz; @Gabriela2; 