collaborators

10 papers

math.GT2026

Limit sets of mapping class groups

Hideki Miyachi, Ken'ichi Ohshika

We introduce the notions of horospherical limit point and big horospherical limit point in the projective measured foliation space for a subgroup of the mapping class group, which…

math.DG2026

On the construction of geographical maps: Lagrange, Chebyshev, Darboux and Milnor

Hideki Miyachi, Ken'Ichi Ohshika, Athanase Papadopoulos

Lagrange, Chebyshev, and Darboux, in 1779, 1856, and 1911, respectively, wrote articles all bearing the same title, \emph{On the Construction of Geographical Maps}. In 1969, Milnor…

math.MG2026

Convergence-Symmetric Metric Spaces

Ismail Saglam, Ken'Ichi Ohshika, Athanase Papadopoulos +1

We study some basic properties of spaces which satisfy the usual axioms of a metric space but without the symmetry axiom. We realised that such a study is needed in view of the rel…

math.GT2026

The combinatorial structure of the unit tangent spheres and cotangent spheres of Teichm{ü}ller space with Thurston's Finsler metric

Ken'Ichi Ohshika, Athanase Papadopoulos

We prove several new results on the combinatorial structures of the unit spheres of the norms induced by Thurston's metric on the tangent and cotangent spaces of the Teichm{ü}ller…

math.CV2026

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…

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…