Author(s): D. Gilman et al. The formation of gravitationally bound overdensities of dark matter (DM), or halos, is a generic prediction of theories with particle DM. We present a measurement of halo properties in 28 quadruple image strong lens systems recently observed by JWST, and use these observations to constrain the free-… [Phys. Rev. Lett. 137, 081004] Published Tue Aug 18, 2026