  Features of the energy landscape sampled by supercooled liquids are
numerically analyzed for several Lennard-Jones like model systems. The
properties of quasisaddles (minima of the square gradient of potential energy
W=|grad V|^2), are shown to have a direct relationship with the dynamical
behavior, confirming that the quasisaddle order extrapolates to zero at the
mode-coupling temperature T_MCT. The same result is obtained either analyzing
all the minima of W or the saddles (absolute minima of W), supporting the
conjectured similarity between quasisaddles and saddles, as far as the
temperature dependence of the properties influencing the slow dynamics is
concerned. We find evidence of universality in the shape of the landscape:
plots for different systems superimpose into master curves, once energies and
temperatures are scaled by T_MCT. This allows to establish a quantitative
relationship between T_MCT and potential energy barriers for LJ-like systems,
and suggests a possible generalization to different model liquids.
