Fluid Models for Kinetic Equations in Swarming Preserving Momentum

.We study kinetic models for swarming. The interaction between individuals is given by self-propelling and friction forces, alignment, and noise. We consider that each individual relaxes its velocity toward some average velocity, such that the total momentum does not change. We concentrate on fluid models obtained when the time and space scales become very large. We derive first and second order approximations.Keywordsswarmingasymptotic analysisalignmentMSC codes92D5082C4092C10