High frequency viscoelasticity of soft particle glasses

The storage and loss moduli for jammed soft particles are studied computationally a variety of interparticle potentials volume fractions. qualitative behavior the modulus is independent nature potential. frequency dependence computed in simulations described by universal logistic formula exhibiting two plateaus at low high frequencies. While high-frequency G∞ follows prediction Zwanzig–Mountain expression, which depends on pair distribution function pairwise potential, no such exists low-frequency G0. Here, we show that given fraction G0∼G∞/gmax, where gmax maximum function. form near-field drag forces between particles. At moderate to frequency, increases with according power law whose exponent related force expression sliding Computational predictions match most experimental observations but some discrepancies observed indicating beyond particle interactions