• Professor
    • Peter Stevenhagen
    • Universiteit Leiden
    • Number Theory

Escher and Droste in Groningen

The Droste effect is a special visual effect that occurs when a picture contains a smaller image of itself. This leads to recursive images that can potentially be repeated ad infinitum. Escher’s 1956 Print Gallery presents a mathematical puzzle based on this effect. I will present Hendrik Lenstra’s mathematical explanation of this puzzle using the mesmerizing visual illustrations created by the Leiden number theory group.


Peter Stevenhagen is a number theorist who spent the previous academic year at the Max Planck Institute in Bonn and at CIRM-Luminy as Jean Morlet chair and organizer of a special semester on Arithmetic Statistics. He is the director of the joint European Algant master program in algebra, geometry and number theory and is currently involved in establishing International Mathematics Masters in low and middle income countries.

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