Johan Comparat

Johan Comparat is a Researcher at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany. His academic background includes a PhD from Marseille focused on baryonic acoustic oscillations with emission line galaxies, followed by research on simulated Universes in Madrid, Spain. He currently studies the Universe's large-scale structure in the X-ray domain at MPE.

Research Focus: Comparat specializes in multi-wavelength cosmology, with emphasis on:

• Observational cosmology and galaxy formation/evolution
• X-ray astrophysics (eROSITA/eBOSS surveys)
• Cross-correlations between X-ray sources and galaxies
• Cosmological simulations and mock catalog development

Publication Trends: Recent work (2022-2025) centers on eROSITA all-sky survey data analysis, featuring cluster abundance studies, gravity model tests, and X-ray/galaxy cross-correlations. Earlier contributions include SDSS-IV emission-line galaxy cosmology and luminosity function measurements.

PhD Advisees:

• S. Shreeram (2023–present)
• Y. Zhang (2021–present)
• R. Seppi (2019–2023)
• J. Ider Chitham (2017–2021)
• F. Albareti (2015–2018)
• S. Rodriguez-Torres (2014–2017)
• G. Favole (2012–2016)

Collaborations: Leads efforts in eROSITA cosmology working groups, develops simulation pipelines (e.g., Skies and Universes), and contributes to SDSS-IV/eBOSS surveys. Maintains public repositories for spectral templates and data products.