New cosmological constraints with extended-Baryon Oscillation
  Spectroscopic Survey DR14 quasar sample
  We update the constraints on the cosmological parameters by adopting the
Planck data released in 2015 and Baryon Acoustic Oscillation (BAO) measurements
including the new DR14 quasar sample measurement at redshift $z=1.52$, and we
conclude that the based six-parameter $\Lambda$CDM model is preferred.
Exploring some extensions to the $\Lambda$CDM models, we find that the equation
of state of dark energy reads $w=-1.036\pm 0.056$ in the $w$CDM model, the
effective relativistic degrees of freedom in the Universe is
$N_\text{eff}=3.09_{-0.20}^{+0.18}$ in the $N_\text{eff}+\Lambda$CDM model and
the spatial curvature parameter is $\Omega_k=(1.8\pm1.9)\times 10^{-3}$ in the
$\Omega_k+\Lambda$CDM model at $68\%$ confidence level (C.L.), and the $95\%$
C.L. upper bounds on the sum of three active neutrinos masses are $\sum
m_\nu<0.16$ eV for the normal hierarchy (NH) and $\sum m_\nu<0.19$ eV for the
inverted hierarchy (IH) with $\Delta\chi^2\equiv
\chi^2_\text{NH}-\chi^2_\text{IH}=-1.25$.
