New Insights into Dark Matter and Cosmic Structures from Recent Studies

Recent studies have unveiled new insights into dark matter and its influence on cosmic structures, significantly advancing our understanding of astrophysics and cosmology. A noteworthy contribution comes from a study on self-interacting dark matter (SIDM), which introduces a generalized Jeans model to describe SIDM density profiles and halo shapes beyond spherical symmetry. This model effectively reproduces halo profiles observed in relaxed galaxies and clusters, highlighting that SIDM halos can differ from collisionless cold dark matter halos in their shapes, despite similar spherically-averaged profiles. The study emphasizes the importance of observational tests via halo shapes, particularly in massive galaxies (M200 approximately 10^12 to 10^13 solar masses), to constrain dark matter self-interactions (source: ArXiv Cosmology).

Another significant proposal aims to construct a dark-matter-only counterpart of the observed universe by combining weak lensing data and baryon censuses. This approach seeks to correct for baryonic effects, such as AGN feedback, which complicate matter clustering models. The proposed method demonstrates a model-independent relation for mapping observed matter clustering to its dark-matter-only counterpart, achieving over 99% accuracy at specific scales and redshifts. By implementing this relation in observations, researchers aim to create a more accurate cosmological laboratory for exploring the dark universe (source: ArXiv Cosmology).

A different perspective on dark matter interactions is provided by a study that investigates dark matter capture in core-collapse supernovae, reviving interest in dark photons. The research revisits cooling constraints of supernovae by including dark matter captured in progenitor stars, which serves as a target for dark photon scattering. This revised analysis suggests the potential formation of a 'dark photosphere' in cases of asymmetric dark matter, which could lead to previously excluded parameter spaces being reopened, altering the understanding of stellar cooling rates in relation to dark sectors (source: ArXiv Cosmology).

Lastly, the assembly history and mass of dark matter halos are further elucidated through the study of stellar halos around brightest cluster galaxies (BCGs). Recent imaging techniques have successfully measured stellar mass density profiles within significant projected annuli, providing a promising proxy for halo mass. The study identifies optimal parameters for measuring these stellar halos, suggesting that stellar masses calculated from specific annuli exhibit less scatter in relation to halo mass than those from simpler measurements. By offering fitting functions for BCG stellar halos, this work aims to enhance future surveys analyzing halo masses through deep imaging data (source: ArXiv Cosmology).