Author(s): Oleksandra Kovalska, Jan von Delft, and Andreas Gleis We present a tangent-space Krylov method for efficient computation of zero-temperature real-frequency spectral functions on top of ground-state matrix product states obtained from the density matrix renormalization group. It relies on projecting the Hamiltonian to the tangent space of the ground-sta… [Phys. Rev. Lett. 137, 176503] Published Tue Oct 20, 2026