Amoretti, AndreaAreán Fraga, DanielGoutéraux, BlaiseMusso, Daniele2020-04-292020-04-292020Amoretti, A., Areán, D., Goutéraux, B. et al. Gapless and gapped holographic phonons. J. High Energ. Phys. 2020, 58 (2020). https://doi.org/10.1007/JHEP01(2020)058http://hdl.handle.net/10347/21873We study a holographic model where translations are both spontaneously and explicitly broken, leading to the presence of (pseudo)-phonons in the spectrum. The weak explicit breaking is due to two independent mechanisms: a small source for the condensate itself and additional linearly space-dependent marginal operators. The low energy dynamics of the model is described by Wigner crystal hydrodynamics. In absence of a source for the condensate, the phonons remain gapless, but momentum is relaxed. Turning on a source for the condensate damps and pins the phonons. Finally, we verify that the universal relation between the phonon damping rate, mass and diffusivity reported in [1] continues to hold in this model for weak enough explicit breakingeng© The Author(s) 2020. Open Access. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are creditedhttps://creativecommons.org/licenses/by/4.0/Effective Field TheoriesHolography and condensed matter physics (AdS/CMT)Space-Time SymmetriesSpontaneous Symmetry Breakingjournal article10.1007/JHEP01(2020)0581029-8479open access