1 department of mathematics university of south florida tampa, fl 33620, usa 2 department of mathematics and statistics brock university st. catharines, on l2s3a1, canada 3 department of mathematics institute for advance studies in basic science (iasbs) 45137-66731, zanjan, iran Abstract. Bi-Hamiltonian hierarchies of soliton equations are derived from geometric nonstretching (inelastic) curve flows in the Hermitian symmetric spaces SU (n + 1)/U (n) and SO(2n)/U (n). The derivation uses Hasimoto variables defined by a moving parallel frame along the curves. As main results, new integrable multi-component versions of the Sine-Gordon (SG) equation and the modified Korteveg-de Vries (mKdV) equation, as well as a novel nonlocal multi-component version of the nonlinear Schrödinger (NLS) equation are obtained, along with their bi-Hamiltonian structures and recursion operators. These integrable systems are unitarily invariant and correspond to geometric curve flows given by a non-stretching wave map and a mKdV analog of a non-stretching Schrödinger map in the case of the SG and mKdV systems, and a generalization of the vortex filament bi-normal equation in the case of the NLS systems. N x = −κT + τB,B x = −τ N x , while the tangential coefficient a is determined by a x = κb due to the non-stretching property of the curve. When b = a = 0 and c = κ, the curve γ undergoes a bi-normal flow γ t = κB. This flow equation physically describes the motion of a vortex filament in incompressible fluids [5]. The induced flow on (κ, τ ) turns out to be equivalent to the NLS equation for the Hasimoto variable u = κ exp(i τ dx) [5]. Moreover, the Lax pair and bi-Hamiltonian operators for the NLS equation turn out to be encoded in a simple way in the structure equations of a moving frame formulation of the curve flow [3, 4], where the Hasimoto transformation from (κ, τ ) to u corresponds geometrically to a gauge transformation from a Frenet frame to a parallel frame given by rotating the vectors (N,B) in the normal plane by an angle θ(x) = − τ dx along the curve [6]. Unlike a Frenet frame, a parallel frame has a rigid gauge freedom consisting of a constant rotation φ applied to the vectors (N,B) in the normal plane. Under this rigid gauge transformation, u transforms to e iφ u by a constant phase rotation, and so u is not an invariant of the curve like (κ, τ ) but instead has the geometrical meaning of a U(1)-covariant of the curve [4].Similarly, all of the symmetries of the NLS equation themselves correspond to geometrical curve flows in Euclidean space, and in particular the first higher symmetry in the NLS hierarchy is given by γ t = κτB + κ xN + 1 2T with the Hasimoto variable u satisfying the complex modified Korteveg-de Vries (mKdV) equation u t = u xxx + 3 2 |u| 2 u x . This flow equation physically describes axial motion of a vortex filament [7]. It is also an integrable system, sharing the same integrability properties as the NLS equation.A broad generalization of parallel frames and Hasimoto variables has been obtained in work...