Recent experimental developments in diverse areas—ranging from cold atomic gases to
light-driven semiconductors to microcavity arrays—move systems into the focus which are …

Important properties of a particle, wave or a statistical system depend on the form of a
dispersion relation (DR). Two commonly-discussed dispersion relations are the gapless …

Out of equilibrium, a lack of reciprocity is the rule rather than the exception. Non-reciprocity
occurs, for instance, in active matter,,,,–, non-equilibrium systems,–, networks of neurons …

A bstract We investigate the low-energy dynamics of systems with pseudo-spontaneously
broken U (1) symmetry and Goldstone phase relaxation. We construct a hydrodynamic …

When global continuous symmetries are spontaneously broken, there appear gapless
collective excitations called Nambu–Goldstone modes (NGMs) that govern the low-energy …

We build an effective field theory (EFT) for quasicrystals--aperiodic incommensurate lattice
structures--at finite temperature, entirely based on symmetry arguments and a well-define …

A bstract Pseudo-Goldstone modes appear in many physical systems and display robust
universal features. First, their mass m obeys the so-called Gell-Mann-Oakes-Renner …

A bstract The coset construction is a tool for systematically building low energy effective
actions for Nambu-Goldstone modes. This technique is typically used to compute time …

A bstract We provide a comprehensive classification of isotropic solid and fluid holographic
models with broken translational invariance. We describe in detail the collective modes in …

A bstract We perform a detailed analysis of a large class of effective holographic models with
broken translations at finite charge density and magnetic field. We exhaustively discuss the …