Anomalous dynamics at the hard-sphere glass transition.

We use X-ray photon correlation spectroscopy to study the dynamics of hard sphere suspensions and report the emergence of ergodicity restoring anomalous intermittent relaxation modes in the highest concentration suspension that is estimated to be above the glass transition concentration. We associate these phenomena with non-thermal stress induced relaxations and support our interpretation by a direct comparison of the results with predictions of the mode coupling theory.