5 papers
The Ptolemy-Alhazen problem with source at infinity
Masayo Fujimura, Matti Vuorinen
We study the well-known Ptolemy-Alhazen problem on reflection of light at the surface of a spherical mirror in the case when the source of light is very far from the mirror.
Hilbert metric and Hölder continuity
Åahsene Altınkaya, Masayo Fujimura, Marcelina Mocanu +1
We prove several formulas for the Hilbert metric in the unit disk and apply these results to study quasiregular mappings of the unit disk onto a bounded convex domai…
On distortion of quasiregular mappings of the upper half plane
Masayo Fujimura, Matti Vuorinen
We prove a sharp result for the distortion of a hyperbolic type metric under -quasiregular mappings of the upper half plane. The proof makes use of a new kind of Bernoulli inequ…
Hilbert metric and quasiconformal mappings
Sahsene Altinkaya, Masayo Fujimura, Matti Vuorinen
We prove a functional identity between the Hilbert metric and the visual angle metric in the unit disk. The proof utilizes the Poincaré hyperbolic metric in terms of which both me…
Visual angle metric in the upper half plane
Masayo Fujimura, Oona Rainio, Matti Vuorinen
We prove an identity which connects the visual angle metric and the hyperbolic metric of the upper half plane . The proof is ba…