Jamming: A Peek Behind the Curtain

We will discuss two of the ``dirty little secrets'' concerning the (anomalous) scaling of the elastic moduli near jamming. First, there is no linear response near jamming, and we propose a novel scaling law for the onset of rearrangements as function of number of particles and distance to the jamming point. Second, the elastic moduli obtained from the dynamical matrix have a very broad distribution, and we discuss how to deal with packings with negative elastic moduli.