English

Waves within a network of slowly time-modulated interfaces: time-dependent effective properties, reciprocity and high-order dispersion

Mathematical Physics 2026-03-31 v1 math.MP

Abstract

We consider wave propagation through a 1D periodic network of slowly time-modulated interfaces. Each interface is modelled by time-dependent spring-mass jump conditions, where mass and rigidity interface parameters are modulated in time. Low-frequency homogenisation yields a leading-order model described by an effective time-dependent wave equation, i.e.\ a wave equation with effective mass density and Young's modulus which are homogeneous in space but depend on time. This means that time-dependent bulk effective properties can be created by an array where only interfaces are modulated in time. The occurrence of k-gaps in case of a periodic modulation is also analysed. Second-order homogenisation is then performed and leads to an effective model which is reciprocal but encapsulates higher-order dispersive effects. These findings and the limitations of the models are illustrated through time-domain simulations.

Keywords

Cite

@article{arxiv.2603.27641,
  title  = {Waves within a network of slowly time-modulated interfaces: time-dependent effective properties, reciprocity and high-order dispersion},
  author = {Michaël Darche and Raphaël Assier and Sébastien Guenneau and Bruno Lombard and Marie Touboul},
  journal= {arXiv preprint arXiv:2603.27641},
  year   = {2026}
}