Abstract

Context. Current studies of large-scale asymmetries (i.e., lopsidedness) in the stellar density distribution of disk galaxies have mainly focused on the Local Universe. However, recent observations have found a significant fraction (over 60%) of lopsided galaxies at high redshift (i.e., 1.5?z?3), which is significantly larger than the fraction (?30%) observed in the nearby Universe. Aims. We aim to understand whether simulations can reproduce the observed fraction of lopsided galaxies at high redshift. We also consider whether the more widespread lopsidedness at high redshift (rather than low-redshift) could be associated with environmental mechanisms being more effective in producing lopsided perturbations at high redshift. Methods. At each redshift between 01:10 and gas accretion with subsequent star formation can produce lopsided perturbations at all redshifts, but they are both significantly more effective at high redshift. Conclusions. These results suggest that the mechanisms behind lopsidedness vary across cosmic time, with a greater influence from environmental interactions and gas accretion at higher redshift. © 2025 The Authors.