Rheology discussions: The physics of dense suspensions

The following set of discussions is a complement to the recent special issue of the Journal of Rheology on the Physics of Dense Suspensions edited by two of us [1]. The discussions took place during the virtual symposium entitled “Physics of Dense Suspensions” (PDS) held on July 9–10, 2020, in response to the broad interest raised by the special issue. Soon after the special issue appearance, in fact, the COVID-19 pandemic resulted in the loss of standard in-person meeting venues. A virtual meeting was, organized to accommodate the desire expressed by many to discuss the fundamental questions brought to focus. The symposium, which was free of charge, attracted more than 500 registered participants from around the world and provided a platform for presentations by authors, followed by question-and-answer periods. The latter periods were characterized by quite lively discussions, out of which grew some consensus but also some points...