@article{powell_vegetti_mckean_white_ferreira_may_spingola_2023, title={A lensed radio jet at milli-arcsecond resolution - II. Constraints on fuzzy dark matter from an extended gravitational arc}, volume={524}, ISSN={["1365-2966"]}, DOI={10.1093/mnrasl/slad074}, abstractNote={ABSTRACT
               Using a single gravitational lens system observed at ≲ 5 mas resolution with very long baseline interferometry, we place a lower bound on the mass of the fuzzy dark matter (FDM) particle, ruling out mχ ≤ 4.4 × 10−21 eV with a 20:1 posterior odds ratio relative to a smooth lens model. We generalize our result to non-scalar and multiple-field models, such as vector FDM, with mχ,vec > 1.4 × 10−21 eV. Due to the extended source structure and high angular resolution of the observation, our analysis is directly sensitive to the presence of granule structures in the main dark matter halo of the lens, which is the most generic prediction of FDM theories. A model based on well-understood physics of ultra-light dark matter fields in a gravitational potential well makes our result robust to a wide range of assumed dark matter fractions and velocity dispersions in the lens galaxy. Our result is competitive with other lower bounds on mχ from past analyses, which rely on intermediate modelling of structure formation and/or baryonic effects. Higher resolution observations taken at 10–100 GHz could improve our constraints by up to two orders of magnitude in the future.}, number={1}, journal={MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, author={Powell, Devon M. and Vegetti, Simona and McKean, J. P. and White, Simon D. M. and Ferreira, Elisa G. M. and May, Simon and Spingola, Cristiana}, year={2023}, month={Sep}, pages={L84–L88} }
 @article{luu_mocz_vogelsberger_may_borrow_tye_broadhurst_2023, title={Nested solitons in two-field fuzzy dark matter}, volume={527}, ISSN={["1365-2966"]}, DOI={10.1093/mnras/stad3482}, abstractNote={ABSTRACT
               Dark matter as scalar particles consisting of multiple species is well motivated in string theory where axion fields are ubiquitous. A two-field fuzzy dark matter (FDM) model features two species of ultralight axion particles with different masses, m1 ≠ m2, which is extended from the standard one-field model with $m_a \sim 10^{-22} \, {\rm eV}$. Here we perform numerical simulations to explore the properties of two-field FDM haloes. We find that the central soliton has a nested structure when m2 ≫ m1, which is distinguishable from the generic flat-core soliton in one-field haloes. However, the formation of this nested soliton is subject to many factors, including the density fraction and mass ratio of the two fields. Finally, we study non-linear structure formation in two-field cosmological simulations with self-consistent initial conditions and find that the small-scale structure in two-field cosmology is also distinct from the one-field model in terms of DM halo counts and soliton formation time.}, number={2}, journal={MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, author={Luu, Hoang Nhan and Mocz, Philip and Vogelsberger, Mark and May, Simon and Borrow, Josh and Tye, S-H Henry and Broadhurst, Tom}, year={2023}, month={Nov}, pages={4162–4172} }