Article
Astronomy & Astrophysics
Andrea Maccio, Daniel Huterer Prats, Keri L. Dixon, Tobias Buck, Stefan Waterval, Nikhil Arora, Stephane Courteau, Xi Kang
Summary: Through simulations, it has been shown that dwarf galaxies can lose up to 80% of their dark matter content and see a significant change in the dark matter-to-stellar mass ratio after interactions with central galaxies. These findings align with observations of NGC 1052-DF2 and NGC 1054-DF4.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Jose Beltran Jimenez, Dario Bettoni, David Figueruelo, Florencia A. Teppa Pannia, Shinji Tsujikawa
Summary: In this study, a cosmological scenario is considered where the dark sector is described by two perfect fluids interacting through a velocity-dependent coupling. The equations governing this system are obtained with a Lagrangian formulation, and stability conditions are derived to avoid ghosts and Laplacian instabilities. The interaction of the dark components is shown to suppress dark matter clustering at late times, potentially alleviating tensions related to sigma(8) and H-0.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Chong-Bin Chen, Jiro Soda
Summary: This study develops an accurate Boltzmann code to calculate the linear growth of plasmas and investigates the growth of structure in a mixed model of cold dark matter and two-axion dark matter. The study finds that an effective single axion can be used to characterize the two-axion cosmology and generalizes this description to multi-axion dark matter cosmology. Furthermore, it compares the results with those of a warm dark matter model and calculates halo mass functions for the mixed model.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Keita Todoroki, Mikhail Medvedev
Summary: The possibility of dark matter being multicomponent has important implications for resolving cosmological problems on a small scale. The 2cDM model can explain the observational trends seen in dwarf galaxy and galaxy cluster haloes, and it also provides an open window for other possible alternative dark matter models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Adriana Bariego-Quintana, Felipe J. Llanes-Estrada, Oliver Manzanilla Carretero
Summary: The flattening rotation velocity v(r) -> constant discovered by Rubin and collaborators in the SPARC galaxy-rotation data is in line with Kepler's law in one less dimension. Elongated dark matter distributions, with their axis of prolateness perpendicular to the galactic plane, naturally reproduce this phenomenon. Detailed fits to the rotation data also support this theoretical understanding, showing that elongated distributions provide a better fit than purely spherical ones.
Article
Astronomy & Astrophysics
Umberto Maio, Matteo Viel
Summary: In this study, the implications of the latest JWST data on the nature of dark matter are investigated. High-redshift galaxies observed by JWST are compared with hydrodynamical simulations in both the standard cold dark matter model and warm dark matter models with a suppressed linear matter power spectrum. The results show that the current data are consistent with both cold dark matter and warm dark matter models with m(WDM) > 2 keV.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
J. A. Sellwood, R. H. Sanders
Summary: Recent observations suggest that the ultradiffuse galaxy AGC 114905 has a rotating disc without the need for dark matter. This is surprising because a non-dark matter Newtonian disc would be expected to be unstable. N-body simulations confirm this expectation, raising questions about the galaxy's lack or scarcity of dark matter. It is also suggested that overestimating the inclination of the system could reconcile the observed rotation curve with the presence of a massive dark matter halo.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Particles & Fields
Dalibor Perkovic, Hrvoje Stefancic
Summary: Galaxy rotation curves are considered strong evidence for the existence of dark matter or alternative mechanisms. This study presents a model-independent approach to test the hypothesis that dark matter behaves as a barotropic fluid. Using rotation curve data of the Milky Way, constraints on the speed of sound in the barotropic fluid are obtained, demonstrating the potential of this approach. The study also discusses technical challenges, limitations, and possible future extensions and improvements.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
J. Vega-Ferrero, J. M. Dana, J. M. Diego, G. Yepes, W. Cui, M. Meneghetti
Summary: The study compares the statistics and morphology of giant arcs in galaxy clusters using different models, finding that self-interacting dark matter produces fewer but more magnified arcs. The probability of interaction is higher in colliding clusters and in denser regions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Nicola C. Amorisco, James Nightingale, Qiuhan He, Aristeidis Amvrosiadis, Xiaoyue Cao, Shaun Cole, Amy Etherington, Carlos S. Frenk, Ran Li, Richard Massey, Andrew Robertson
Summary: This article investigates the detectability of low-mass dark matter haloes in warm dark matter models. The authors find that haloes are harder to detect when they are either behind or in front of the lens. Furthermore, the perturbing effect of haloes increases with their concentration, and accounting for the scatter in the mass-concentration relation can significantly boost the expected number of detections.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Han Aung, Daisuke Nagai, Erwin T. Lau
Summary: Recent studies have found discrepancies between the location of the accretion shock and the splashback radius of dark matter, with the former being larger by 20-100%. This has implications for multiwavelength studies of galaxy clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
K. Gopika, Shantanu Desai, Aseem Paranjape
Summary: A large number of observations have found that the dark matter halo surface density is nearly constant for different galaxies. However, it is still unknown whether this constancy on galactic scales can be explained within Lambda cold dark matter (?CDM).
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Geoff Beck, Michael Sarkis
Summary: Recent radio-frequency probes using the ATCA and ASKAP telescopes have made significant progress in indirectly constraining the properties of dark matter, surpassing the constraining power of Fermi-LAT data. This study reexamines the potential of galaxy clusters, which are often overlooked due to radio backgrounds, by extrapolating known cluster surface brightness profiles observable with MeerKAT. Despite baryonic backgrounds, clusters can compete with dwarf galaxies, with extrapolated Coma data ruling out weakly interacting massive particles of mass < 700 GeV annihilating via b-quarks. This is due to the clash between the inner shape of the dark matter halo and the flat inner profile of radio halos, with supporting evidence in the literature for Navarro-Frenk-White-like Einasto profiles.
Article
Astronomy & Astrophysics
Rebecca K. Leane, Tim Linden, Payel Mukhopadhyay, Natalia Toro
Summary: This passage discusses a new scenario in which celestial bodies can enhance the efficiency of dark matter annihilation events, leading to distinctive annihilation signals. By analyzing data from Fermi and H.E.S.S., new constraints on the dark matter-nucleon scattering cross section for different mass scales of dark matter can be set.
Article
Astronomy & Astrophysics
S. Arcari, E. Pinetti, N. Fornengo
Summary: This paper introduces a method of using the cross-correlation technique to search for dark matter signals by observing information in cosmic voids. It is found that the signal-to-background ratio for decaying dark matter versus astrophysical sources is significantly higher in voids compared to halos, making it easier to detect pure dark matter signals.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
