Inside Universität Hamburg's largest research partnership: Heidelberg University

Behind Universität Hamburg's research output sits a defining relationship: 3,483 co-authored works with Heidelberg University (Germany) in the five years to 2025, the university's single largest collaboration.

It anchors an unusually connected research base: 1,147 collaborating institutions across 80 countries, producing 66,492 joint works over the window, with international co-authors on 44% of output.

The collaborative work travels: its field-weighted citation impact stands at 2.81, where the world average is 1.0.

The Research Collaboration Index, the first global account of how universities actually collaborate, publishes its first full edition on Tuesday 15 September at 09:00 UK.

Every figure derives from the open global research record and is checkable at source.