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Abstract

Active matter refers to systems where each particle consume energy from the surroundings and convert it into mechanical energy. Typical examples are biological systems like flocks of birds, bacterial suspensions or mixtures of cytoskeletal filaments and motor proteins, or synthetic systems like vibrated layers of granular rods. Such types of matter are intrinsically out of equilibrium and experiences phases that are not observed in equilibrium. One such phase is active turbulence which is a chaotic flow state observed in e.g. bacterial suspensions. A characteristic of this phase is the spontaneous creation and annihilation of topological defects. The presence of the defects induces stresses which alters the active flow. In this talk I will discuss the self-induced flows generated by topological defects in an active nematic film and in an active system with polar symmetry. The induced flow is contributing to the dynamics of the topological defects by making them self-propelled and by mediating interactions between them. We consider the effects of viscus dissipation and frictional damping with the substrate, and the effects of a spatial variation in the activity.