# The $h$-index and multi-author $h_m$-index for individual researchers in condensed matter physics

## TL;DR

This study analyzes the $h$-index and multi-author $h_m$-index in condensed matter physics, comparing empirical data with theoretical models and proposing deviations as additional impact measures.

## Contribution

It evaluates the $h$-index and $h_m$-index against multiple models, highlighting deviations as supplementary impact indicators in condensed matter physics.

## Key findings

- Deviations from theoretical models can indicate research impact.
- The $h_m$-index analysis complements $h$-index insights.
- Empirical data aligns with some models but shows notable deviations.

## Abstract

The characteristics of the $h$-index in the field of condensed matter physics are studied using high-quality data from ResearcherID. The results are examined in terms of theoretical descriptions of the $h$-index' overall dependence on a researcher's total number of published papers, and total number of citations. In particular, the models by Hirsch, Egghe and Rousseau, as well as by Gl\"anzel and Schubert are examined. Special emphasis is placed on the deviations from such statistical descriptions, and it is argued that the deviation of a particular researcher's $h$ value from the Egghe-Rouseau model's prediction can be used as a supplementary measure of impact. A corresponding analysis with similar results is performed using the multi-author $h_m$-index.