research statement for assistant professorship (W1, pure mathematics in Germany)
Assuming you speak German, you could search for guidelines on the evaluation of "Juniorprofessoren" which are published by many universities ("Leitfaden zur Evaluierung von Juniorprofessuren), e.g., see here for one from the University of Magdeburg: http://www.uni-magdeburg.de/rektorat/JPLF.pdf. In such guidelines, you will often find at least information on the content, see point 4.5 in the linked document.