This suggests that globular clusters can be used as tracers of the dark matter distribution in other massive clusters where gravitational lensing constraints are scarce but globular clusters can be de

The gap

Consensus across the literature

Supporting evidence — 3 representative gaps

• Study on Chronological Development of Cosmology and Evaluation of Mystery of Universe (2026) · doi

  Whether it is a constant energy density like cosmological constant or something that evolves over time is an open question that future missions like the Roman Space Telescope aim to answer. By addressing open questions about dark matter, magnetic fields, time, neutrinos, inflation, and even the possibility of a simulated reality, this collection illustrates how modern astrophysics and cosmology are increasingly interwoven with cutting-edge physics, speculative ideas, and technological innovation. Globular cluster formation and evolution in the context of cosmological galaxy assembly: Open questions. The enduring 5-sigma discrepancy suggests "something has been found" that is not yet understood, potentially requiring new physics beyond the standard model as we know so far.

  Keywords: open constant like cosmological something time questions physics whether energy density evolves question future missions
• Stellar streams in the Gaia era (2024) · doi

  Simple by nature, stellar streams have been excellent test beds for theories of galaxy formation and cosmology. Their mass function indicates globular clusters are a regular product of clustered star formation (§3). Their kinematics reveal mas- sive dark matter halos around both the Milky Way and the Large Magellanic Cloud (§3). Their mere presence confirms a basic tenet of cold dark matter cosmologies that galaxies grow at least in part hierarchically (§2). We expect that all of these aspects will be further developed in the future, but perhaps the most exciting prospect for streams is constraining the nature of dark matter (§4). To that end, we propose that the goal for the next decade should be an unambiguous association of a stream perturbation with a dark subhalo (≲ 106 M⊙). Such a detection would con- firm the prediction of the ΛCDM model that halos exist below -2022 [deg]5106Msubhalo1.7104Mprogenitor-505Vr [km s1]obs = 0.1 km s1-60-50-40-30-20-1001 [deg]-505Vr [km s1]obs = 2 km s1been conducted in the past couple of decades, but they ob- tained a fairly small number of stream members because they were either limited to bright targets (e.g., APOGEE, Majew- ski et al. 2017; RAVE, Steinmetz et al. 2020; GALAH, Buder et al. 2021; Gaia, Katz et al. 2023), and/or employed a sparse targeting strategy that often missed the narrow streams’ profiles (e.g., SEGUE, Yanny et al. 2009; H3, Conroy et al. 2019). On the other hand, dedicated programs using wide-field, heavily multiplexed spectrographs can efficiently target stream mem- bers (e.g., Li et al., 2021). Excitingly, several such current and soon-operational facilities have a dedicated streams pro- gram, including DESI (Dark Energy Spectroscopic Instrument, Cooper et al., 2023), WEAVE (William Herschel Telescope En- hanced Area Velocity Explorer, Jin et al., 2023), 4MOST (4- metre Multi-Object Spectroscopic Telescope, de Jong et al., 2019), and PFS (Prime Focus Spectrograph, Takada et al., 2014). In addition, the Via Project3 is currently building twin high-resolution spectrographs for the 6.5 m MMT and Magel- lan telescopes that can efficiently survey the halo at ≲ 0.1 km/s precision (first light expected in early 2027). On a decade time- scale, the Mauna Kea Spectroscopic Explorer (MSE) has been proposed as a new 11.25 m facility, designed in part as the ulti- mate high-resolution follow-up of Gaia targets (The MSE Sci- ence Team et al., 2019). The ideal outcome of these projects would be a complete (magnitude limited) census of member stars with precise 6D kinematics and multi-element chemical abundances for all of the Milky Way streams. Community repository for stream data. The wide variety of dynamical processes affect streams on different orbits to a different extent (§4.1), so the key to disentangling signatures of dark-matter subhalos will be simultaneous modeling of the entire population of streams. So far, such studies were limited by the non-uniformity of stream observations, large

  Keywords: streams dark stream matter limited spectroscopic nature formation kinematics halos milky large part decade targets
• A tight relation between the distribution of globular clusters and dark matter in AS1063 (2026) · doi

  This suggests that globular clusters can be used as tracers of the dark matter distribution in other massive clusters where gravitational lensing constraints are scarce but globular clusters can be detected more easily; for instance, in low-redshift galaxy clusters.

  Keywords: clusters globular suggests used tracers dark matter distribution massive gravitational lensing constraints scarce detected easily