Model-independent reconstruction of $f(Q)$ non-metric gravity
  We consider gravity mediated by non-metricity, with vanishing curvature and
torsion. The gravitational action, including an arbitrary function of the
non-metric scalar, is investigated in view of characterizing the dark energy
effects. In particular, we present a method to reconstruct the $f(Q)$ action
without resorting to \emph{a priori} assumptions on the cosmological model. To
this purpose, we adopt a method based on rational Pad\'e approximations, which
provides a stable behaviour of the cosmographic series at high redshifts,
alleviating the convergence issues proper of the standard approach. We thus
describe how to reconstruct $f(Q)$ through a numerical inversion procedure
based on the current observational bounds on cosmographic parameters. Our
analysis suggests that the best approximation for describing the accelerated
expansion of the universe is represented by a scenario with $f(Q)=\alpha+\beta
Q^{n}$. Finally, possible deviations from the standard $\Lambda$CDM model are
discussed.
