In modern research, a new class of gaseous systems, so-called active gases arouses the interest of many scientists. Unlike gas molecules at thermal equilibrium, the constituent particles of active gases are self-propelled, and mutual interactions are typically highly dissipative. Such systems are far from thermal equilibrium and exhibit a wealth of patterns on macroscopic scales, which ultimately arise as a consequence of activity and dissipation at the microscopic level. Its distinctive capabilities to mediate between the microscopic and macroscopic views on physical systems therefore makes the Boltzmann equation a conceptually highly appealing tool in understanding the unusual collective dynamics of such active systems. more

Phenotypic heterogeneity and genetic diversity are common strategies of viral and bacterial populations to rapidly adapt to changing environmental conditions. While the maintenance of genetic diversity has recently been subject to extensive studies, little is known about the evolution of phenotypic heterogeneity. Here, we are interested in the conditions that lead to the loss of genetic diversity and the establishment of phenotypic heterogeneity. When does phenotypic specialization dominate in a population and under which conditions is the best strategy for individuals to be generalists? more