Tag Archives: Hyperbolic geometry

A tale of two arithmetic lattices

For almost 50 years, Paul Sally was a towering figure in mathematics education at the University of Chicago. Although he was 80 years old, and had two prosthetic legs and an eyepatch (associated with the Type 1 diabetes he had his … Continue reading

Posted in Hyperbolic geometry, Number theory | Tagged , , | 2 Comments

Random turtles in the hyperbolic plane

My eldest daughter Lisa recently brought home a note from her school from her computer class teacher. Apparently, the 5th grade kids have been learning to program in Logo, in the MicroWorlds programming environment. I have very pleasant memories of … Continue reading

Posted in Hyperbolic geometry, Probability, Visualization | Tagged , , , , , , | 5 Comments

Bridgeman’s orthospectrum identity

Martin Bridgeman gave a nice talk at Caltech recently on his discovery of a beautiful identity concerning orthospectra of hyperbolic surfaces (and manifolds of higher dimension) with totally geodesic boundary. The -dimensional case is (in my opinion) the most beautiful, … Continue reading

Posted in Hyperbolic geometry, Special functions, Surfaces | Tagged , , , , | 5 Comments