Cosmic environment as the primary driver of dwarf satellite statistics

Context. Satellite dwarf galaxies provide key constraints on galaxy formation and evolution, since their abundance and spatial distribution reflect both the host properties and the large-scale environment. Aims. This study quantifies the dependence of satellite populations on the host stellar mass, morphology, and star formation activity across different environments, and traces their evolution with cosmic time within the ΛCDM framework. Methods. The Millennium-II simulation combined with the G11 semi-analytic model is used to construct consistent samples of host galaxies brighter than M_ r <-16 and their satellites (M_*≥ 3, M_⊙, M_ <-9) within the virial radius. Satellite abundance and radial profiles are analysed in cluster, group, and void environments, and their evolution is traced from z=2 to z=0 across three host stellar mass bins. Results. Satellite abundance is correlated strongly with host stellar and bulge mass, whereas host morphology has little independent effect once stellar mass is accounted for. Dense environments suppress satellite populations relative to voids. Correlations between satellite abundance, specific star formation rate, and disk scale length become evident only in groups and clusters. At z=0, radial profiles show strong central concentrations in voids, flattened distributions in clusters, and intermediate trends in groups. Their redshift evolution reveals progressive flattening for low- and intermediate-mass hosts in dense environments, stability for massive hosts, and increasing central concentration in voids. The cosmic evolution of satellite abundance further highlights distinct pathways: gradual accumulation in voids, mass-dependent trends in groups, and strong late-time suppression in clusters. Conclusions. The distribution and abundance of satellite galaxies are governed primarily by environment, with the host stellar mass and cosmic epoch acting as secondary modulators. From the dense interiors of clusters to the isolation of voids, large-scale structure imprints systematic signatures on satellite system assembly. Forthcoming wide-field surveys such as the Legacy Survey of Space and Time (LSST), the ESA Euclid mission (Euclid), and the Nancy Grace Roman Space Telescope are expected to provide stringent tests of these predictions and advance our understanding of the interplay between host properties, environment, and satellite evolution across cosmic time. 5 r