Birth, death, and horizontal flight: Malthusian flocks with an easy plane in three dimensions
Birth, death, and horizontal flight: Malthusian flocks with an easy plane in three dimensions
I formulate the theory of three dimensional ``Malthusian flocks''---i.e., coherently moving collections of self-propelled entities (such as living creatures) which are being ``born'' and ``dying'' during their motion---whose constituents all have a preference for having their velocity vectors lie parallel to the same two-dimensional plane. I determine the universal scaling …