title: Optical analogues of the Newton-Schrödinger equation and boson star evolution.
abstract: Many gravitational phenomena that lie at the core of our understanding of the Universe have not yet been directly observed. An example in this sense is the boson star that has been proposed as an alternative to some compact objects currently interpreted as being black holes. In the weak field limit, these stars are governed by the Newton-Schrodinger equation. Here we present an optical system that, under appropriate conditions, identically reproduces such equation in two dimensions. A rotating boson star is experimentally and numerically modelled by an optical beam propagating through a medium with a positive thermal nonlinearity and is shown to oscillate in time while also stable up to relatively high densities. For higher densities, instabilities lead to an apparent breakup of the star, yet coherence across the whole structure is maintained. These results show that optical analogues can be used to shed new light on inaccessible gravitational objects.
authors.affiliation: School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: Thomas
authors.identifier: 0000-0003-0862-4961
authors.initials: T
authors.lastname: Roger
authors.affiliation: School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: Calum
authors.initials: C
authors.lastname: Maitland
authors.affiliation: School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: Kali
authors.initials: K
authors.lastname: Wilson
authors.affiliation: School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: Niclas
authors.identifier: 0000-0002-9876-5858
authors.initials: N
authors.lastname: Westerberg
authors.affiliation: School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: David
authors.initials: D
authors.lastname: Vocke
authors.affiliation: School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.|College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Ewan M
authors.initials: EM
authors.lastname: Wright
authors.affiliation: School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK.
authors.forename: Daniele
authors.initials: D
authors.lastname: Faccio