Mula, BegoñaSantalla, Silvia N.Rodríguez Laguna, Javier2024-05-202024-05-202021-01-202643-1564http://doi.org/10.1103/PhysRevResearch.3.013062https://hdl.handle.net/20.500.14468/12057We characterize the Casimir forces for the Dirac vacuum on free-fermionic chains with smoothly varying hopping amplitudes, which correspond to ( 1 + 1 )-dimensional [( 1 + 1 )D] curved spacetimes with a static metric in the continuum limit. The first-order energy potential for an obstacle on that lattice corresponds to the Newtonian potential associated with the metric, while the finite-size corrections are described by a curved extension of the conformal field theory predictions, including a suitable boundary term. We show that for weak deformations of the Minkowski metric, Casimir forces measured by a local observer at the boundary are universal. We provide numerical evidence for our results on a variety of (1+1)D deformations: Minkowski, Rindler, anti–de Sitter (the so-called rainbow system), and sinusoidal metrics. Moreover, we show that interactions do not preclude our conclusions, exemplifying this with the deformed Heisenberg chain.eninfo:eu-repo/semantics/openAccessjournal article