Non-thermal processes in radiatively inefficient accretion flows
Radiatively inefficient accretion flows (RIAFs) are formed when accretion rates are sufficiently lower than the Eddington rate. The plasma in RIAFs are so hot and tenuous that Coulomb collisions cannot efficiently thermalize the plasma, allowing to have non-thermal components. Inside RIAFs, turbulence are expected to develop by various magneto-hydrodynamic instabilities, and magnetic reconnection or stochastic acceleration will accelerate the non-thermal particles. In this talk, I will discuss non-thermal phenomena caused by these turbulence and reconnections around RIAFs. If the RIAF is weakly magnetized, the magneto-rotational instability develops and particle acceleration likely occur via stochastic acceleration. I will discuss neutrino emission and particle acceleration in this situation. If the RIAF is strongly magnetized, particle acceleration likely occurs via magnetic reconnection. I will discuss gamma-ray emission and its implications on plasma loading onto jet regions in this situation.