  Correlated many-fermion systems emerge in a broad range of phenomena in warm
dense matter, plasmonics, and ultracold atoms. Quantum hydrodynamics (QHD)
complements common first-principles methods for many-fermion systems and
enables simulations at larger length and longer time scales. While the quantum
Bohm potential is central to QHD, we illustrate its failure for strong
perturbations. We extend QHD to this regime by utilizing the many-fermion
quantum Bohm potential. This opens up the path to more accurate simulations in
strongly perturbed warm dense matter, inhomogeneous quantum plasmas, and on
nano-structure surfaces at scales unattainable with first-principles
algorithms. The many-fermion quantum Bohm potential might also have important
astrophysical applications in developing conformal-invariant cosmologies.
