3 papers
math.DG2026
On the Lambert conformal conical projection and the general map of the Russian Empire
Hideki Miyachi, Ken'Ichi Ohshika, Athanase Papadopoulos +1
The problem of drawing geographical maps is the one of mapping a subset of the sphere, representing a country or some other region on the surface of the Earth, into the Euclidean p…
math.HO2025
On the Marinus--Ptolemy and Delisle--Euler conical maps
Hideki Miyachi, Ken'Ichi Ohshika, Athanase Papadopoulos
We examine connections between the mathematics behind methods of drawing geographical maps due, on the one hand to Marinos and Ptolemy (1st-2nd c. CE) and on the other hand to Deli…
math.CV2024
The horocyclic metric on Teichm{ü}ller spaces
Hideki Miyachi, Ken'Ichi Ohshika, Athanase Papadopoulos
In his paper Minimal stretch maps between hyperbolic surfaces, William Thurston defined a norm on the tangent space to Teichm{ü}ller space of a hyperbolic surface, which he called…