Linear Response of One-Dimensional Liquid 4He to External Perturbations

We study the response of one-dimensional liquid (Formula presented.) to weak perturbations relying on the dynamical structure factor, (Formula presented.), recently obtained via ab-initio techniques (Bertaina et al. in Phys Rev Lett 116:135302, 2016). We evaluate the drag force, (Formula presented.), experienced by an impurity moving along the system with velocity v and the static response function, (Formula presented.), describing the density modulations induced by a periodic perturbation with wave vector q.