Barycentric Calculus in Euclidean and Hyperbolic Geometry: A Comparative Introduction (Second Edition)
暫譯: 歐幾里得與雙曲幾何中的重心微積分：比較導論（第二版）

This unique and richly illustrated book explores barycentric calculus, a geometric method grounded in the concept of the center of gravity. Used to elegantly determine triangle centers through weighted points, barycentric coordinates have long revealed deep insights in Euclidean geometry. Now, this book extends those insights to the fascinating realm of hyperbolic geometry, building a powerful bridge between classical and modern mathematical worlds.In Euclidean geometry, over 3,000 triangle centers have been identified using barycentric coordinates. This book introduces readers to their hyperbolic analogs, uncovering remarkable parallels between triangle centers in Bolyai-Lobachevsky geometry and their Euclidean counterparts. The author's innovative use of Cartesian coordinates, trigonometry, and vector algebra -- adapted for hyperbolic geometry -- equips readers with familiar yet powerful tools to explore unfamiliar terrain.At the heart of the book is the development of hyperbolic barycentric coordinates, or gyrobarycentric coordinates, within the framework of gyrovector spaces -- a novel algebraic structure emerging from Einstein's velocity addition and Möbius addition. These gyrovectors underpin the Klein and Poincaré ball models of hyperbolic geometry, just as traditional vectors underlie analytic Euclidean geometry.Whether you are a researcher in geometry, mathematical physics, or relativity, or simply fascinated by the deep structure of space, this book offers a groundbreaking approach to analytic hyperbolic geometry through barycentric and gyrobarycentric coordinates.