Year: 2026
Type: preprint
Abstract: Boson stars are self-gravitating solitons of the Einstein-Klein-Gordon equations for a massive complex scalar field, and arguably the simplest horizonless compact objects arising in General Relativity. Beyond spherical symmetry, their construction requires solving a system of nonlinear elliptic partial differential equations, a difficult task per se and that each group has traditionally addressed with its own numerical implementation. A systematic comparison of different methods applied to the same physical model has so far been lacking. In this work, we carry out such a comparison for the two simplest non-spherical configurations: rotating boson stars and static dipolar boson stars. We employ three independent codes, based respectively on finite differences (FIDISOL/CADSOL), finite elements (FreeFem), and spectral methods (Kadath), and assess their accuracy through different diagnostics. The three solvers agree on the global observables to typically eight significant digits. We further compare the runtime of each code on identical hardware and provide precise benchmark values of the relevant physical quantities, intended to serve as reference data for future numerical studies of boson stars. As a further proof of concept, we also present the use of physics-informed neural networks to construct a rotating Q-ball solution.
Source: arXiv (Cornell University)
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: CERN, Ministerio de Ciencia, Innovación y Universidades, European Commission, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Center for Research and Development in Mathematics and Applications, Horizon 2020 Framework Programme, HORIZON EUROPE Framework Programme, Fundação para a Ciência e a Tecnologia, Agencia Estatal de Investigación, Institut de Ciències del Cosmos
Awards: G1086179170, G1243611389, G1271475444, Partículas de matéria escura ultra-leves, sombras de buracos negros e ondas gravitacionais, G1610718637, G1760621304, G225231157, G2367368587, G2436355136, G2469431069, Centro de Investigação e Desenvolvimento em Matemática e Aplicações, G2813568340, G3010518541, G3345895242, G3461949579, Testando a hipótese de Kerr com ondas e lentes gravitacionais, G3477743816, G3595636137, G377623426, G3784532101, G3818084518, G4196625222, G4212894969, G4232096390, G46803926, Ondas gravitacionais e buracos negros como detetores de partículas de matéria escura ultra-leve, Searching for new particles with astrophysical compact objects, G5635532810, G5769737447, G5788466760, G6773436493, G7015168732, G7189308598, Centro de Investigação e Desenvolvimento em Matemática e Aplicações, G7395345766, G7436585672, G7525315620, G7805626310, G7825191908, Fundamental fields and compact objects: theory and astrophysical phenomenology, G8394465279, G8667377315, G8822556163
OpenAlex ID: W7214043246