  When dense granular systems are exposed to external forcing, they evolve on
the time scale that is typically related to the externally imposed one (shear
or compression rate, for example). This evolution could be characterized by
observing temporal evolution of contact networks. However, it is not
immediately clear whether the force networks, defined on contact networks by
considering force interactions between the particles, evolve on a similar time
scale. To analyze the evolution of these networks, we carry out discrete
element simulations of a system of soft frictional disks exposed to compression
that leads to jamming. By using the tools of computational topology, we show
that close to jamming transition, the force networks evolve on the time scale
which is much faster than the externally imposed one. The presentation will
discuss the factors that determine this fast time scale.
