A synthetic proof of the spherical and hyperbolic Pythagorean theorem on models in Euclidean and Minkowski space

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autore principale: Maex, Michaël
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866916931037036544
author Maex, Michaël
author_facet Maex, Michaël
contents There are multiple generalisations of the Pythagorean theorem to spherical and hyperbolic geometry. A natural one, involving areas of disks with radii equal to the sides of a proper triangle, was discovered in the hyperbolic case by Maria Teresa Calapso and generalised to the spherical case by Paolo Maraner. All known proofs are analytic, and Maraner posed the question of whether there is a synthetic proof. In this paper, we explain the statement of the theorem in a way that is accessible to a wide audience. Next, we give an elementary geometric proof of this theorem using the sphere in Euclidean space and the hyperboloid in Minkowski space as models for spherical and hyperbolic geometry.
format Preprint
id arxiv_https___arxiv_org_abs_2509_03314
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A synthetic proof of the spherical and hyperbolic Pythagorean theorem on models in Euclidean and Minkowski space
Maex, Michaël
Metric Geometry
51M09, 51M04
There are multiple generalisations of the Pythagorean theorem to spherical and hyperbolic geometry. A natural one, involving areas of disks with radii equal to the sides of a proper triangle, was discovered in the hyperbolic case by Maria Teresa Calapso and generalised to the spherical case by Paolo Maraner. All known proofs are analytic, and Maraner posed the question of whether there is a synthetic proof. In this paper, we explain the statement of the theorem in a way that is accessible to a wide audience. Next, we give an elementary geometric proof of this theorem using the sphere in Euclidean space and the hyperboloid in Minkowski space as models for spherical and hyperbolic geometry.
title A synthetic proof of the spherical and hyperbolic Pythagorean theorem on models in Euclidean and Minkowski space
topic Metric Geometry
51M09, 51M04
url https://arxiv.org/abs/2509.03314