title: Emergent geometries and nonlinear-wave dynamics in photon fluids.
abstract: Nonlinear waves in defocusing media are investigated in the framework of the hydrodynamic description of light as a photon fluid. The observations are interpreted in terms of an emergent curved spacetime generated by the waves themselves, which fully determines their dynamics. The spacetime geometry emerges naturally as a result of the nonlinear interaction between the waves and the self-induced background flow. In particular, as observed in real fluids, different points of the wave profile propagate at different velocities leading to the self-steepening of the wave front and to the formation of a shock. This phenomenon can be associated to a curvature singularity of the emergent metric. Our analysis offers an alternative insight into the problem of shock formation and provides a demonstration of an analogue gravity model that goes beyond the kinematic level.
authors.affiliation: CNR-Istituto Nazionale di Ottica, L.go E. Fermi 6, I-50125 Firenze, Italy.|INFN, Sez. di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy.
authors.forename: F
authors.initials: F
authors.lastname: Marino
authors.affiliation: School of Engineering and Physical Sciences, SUPA, Institute of Photonics and Quantum Sciences Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: C
authors.initials: C
authors.lastname: Maitland
authors.affiliation: School of Engineering and Physical Sciences, SUPA, Institute of Photonics and Quantum Sciences Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: D
authors.initials: D
authors.lastname: Vocke
authors.affiliation: INFN, Laboratori Nazionali di Legnaro, Viale dell' Universita 2, I-35020 Legnaro (PD), Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ortolan
authors.affiliation: School of Engineering and Physical Sciences, SUPA, Institute of Photonics and Quantum Sciences Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: D
authors.initials: D
authors.lastname: Faccio