  This work is a unified study of stable and unstable steady states of 2D
active nematic channel flow using the framework of Exact Coherent Structures
(ECS). ECS are stationary, periodic, quasiperiodic, or traveling wave solutions
of the governing equations that, together with their invariant manifolds,
organize the dynamics of nonlinear continuum systems. We extend our earlier
work on ECS in the preturbulent regime by performing a comprehensive study of
stable and unstable ECS for a wide range of activity values spanning the
preturbulent and turbulent regimes. In the weakly turbulent regime, we compute
more than 200 unstable ECS that co-exist at a single set of parameters, and
uncover the role of symmetries in organizing the phase space geometry. We
provide conclusive numerical evidence that in the preturbulent regime, generic
trajectories shadow a series of unstable ECS before settling onto an attractor.
Finally, our studies hint at shadowing of quasiperiodic type ECS in the
turbulent regime.
