Within a quantum molecular dynamics model we calculate the largest Lyapunov exponent (LLE), density fluctuation and mass distribution of fragments for a series of nuclear systems at different initial temperatures. It is found that the LLE peaks at the temperature (”critical temperature”) where the density fluctuation reaches a maximal value and the mass distribution of fragments is best fitted ...

Motivated by the fact that QCD critical point (CP) belongs to the same universality class as the liquid-gas transition, the dynamical density fluctuations around the CP is analyzed using relativistic fluid dynamics for a viscous fluid. It is shown that relativistic effects on the dynamical structure factor of the density fluctuation appears only in the width of the sound and thermal modes throu...

We report conductivity fluctuation measurements in the La1.82Sr0.18CuO4 high temperature superconducting material. The conductivity fluctuation analysis was performed by utilizing the concept of the logarithmic derivative of the conductivity excess. Close and above the critical temperature Tc, we experimentally determine the occurrence of Gaussian and critical fluctuation regimes. Systematic me...

Recently Phys. Rev. E 68, 016116 (2003)]] proposed an alternative way to compute numerically the fluctuation-dissipation ratios in nonequilibrium critical systems. Using well-known facts of nonequilibrium critical dynamics I show that the leading contributions of the quantities they consider are in fact one-time quantities which are independent of the waiting time. The ratio of these one-time q...

We argue that the event-by-event fluctuation of the proton number is a meaningful and promising observable for the purpose of detecting the QCD critical end point in heavy-ion collision experiments. The long range fluctuation of the order parameter induces a characteristic correlation between protons which can be measured. The proton fluctuation also manifests itself as anomalous enhancement of...