Pseudomomentum: origins and consequences

Abstract The balance of pseudomomentum is discussed and applied to simple elasticity, ideal fluids, the mechanics inextensible rods sheets. A general framework presented in which simultaneous variation an action with respect position, time, material labels yields bulk laws jump conditions for momentum, energy, pseudomomentum. example elasticity space-filling solids treated at length. fluids shown imply conservation vorticity, circulation, helicity, a mathematical similarity noted between evaluation circulation along loop J-integral fracture mechanics. Integration balance, making use prescription singular sources derived by analogy continuous form directly provides propulsive force driving passive reconfiguration or locomotion confined, inhomogeneous elastic rods. conserved angular momentum are identified classification conical sheets rotational inertia bending energy.