Data challenge

The Hubble tension remains one of the most prominent unresolved questions in modern cosmology. The CosmoVerse COST Action paves new routes for dialogue in an effort to better understand—and potentially resolve—this tension. To this end, the CosmoVerse 2026 Data Challenge will enable an intensive and inclusive event aimed at scrutinizing and increasing the transparency of local distance ladder measurements of the Hubble constant. This challenge will bring together experts in the field, both established and emerging, and will focus on the first and second rungs of the distance ladder. Deliverables will include a public repository compiling data and code, accessible to anyone interested in reproducing such measurements and enabling broad participation across the field. Methodologies will be taught during the CosmoVerse 2026 Summer School, and participants will analyze a common dataset to measure the Hubble constant using their own pipelines.

Main coordinator: Dr. Siyang Li