  We obtain characterizations of nonuniform dichotomies, defined by general
growth rates, based on admissibility conditions. Additionally, we use the
obtained characterizations to derive robustness results for the considered
dichotomies. As particular cases, we recover several results in the literature
concerning nonuniform exponential dichotomies and nonuniform polynomial
dichotomies as well as new results for nonuniform dichotomies with logarithmic
growth.
