The Azores Index (A-Index): Balancing Peak Performance and Portfolio Density in Citation Analysis

Although widely adopted, established metrics like the h-index frequently flatten variation beyond the core threshold, while the traditional average citation count remains susceptible to individual outliers and portfolio expansion. We propose the Azores Index ($\mathcal{A}$-index), a novel metric that partitions an author's publication list into three distinct tiers: the top 3 papers, the middle third, and the remainder. The index averages the citations of the top 3 papers, adds the total citations of the middle third, and normalizes the result by the total number of publications. This design simultaneously rewards exceptional impact and consistent mid-level productivity, while strongly penalizing dilution from low-cited papers. We formally define the index, discuss its mathematical properties, and provide illustrative comparisons with established metrics.