Vector nematodynamics with symmetry-driven energy exchange

We review inadequacy of existing nematodynamic theories based on Onsager's near-equilibrium relations and suggest a novel way of establishing relations between nematic orientation and flow, based on the local symmetry between simultaneous rotation of nematic alignment and flow, which establishes energy and momentum exchange between the two without reducing the problem to near-equilibrium conditions. This approach, applied in the framework of the vector-based theory with a variable modulus, involves antisymmetric interactions between nematic alignment and flow. It avoids spurious instabilities in the absence of active inputs and elucidates their cause.