Gentle introduction to quasi-geodesics

Question

Compared to the concept of geodesics the concept of quasi-geodesics seems to be substantially harder to grasp and digest. I was given a promising hint to the concept of quasi-geodesics here but the usual references didn't reveal something like an "easy access" to the concept:

• Google [the very first hit pointing to a paper of G. Perelman]

• Wikipedia

• Encyclopedia of Mathematics

So I am still looking for something like a "gentle introduction to quasi-geodesics".

Answer 1

This is rather self-serving, but I do discuss quasigeodesics in my book with Erik Demaine, Geometric Folding Algorithms: Linkages, Origami, Polyhedra, pp.372-380. I spent some time absorbing the Russian geometry literature before writing that section. Some of the same material is revisited in a more elementary presentation in my book with Satyan Devadoss, Discrete and Computational Geometry, pp.200-205:

I would be interested myself if there is a more "gentle introduction." I don't think so. And at least the way I have presented it in these books, it is, I think, rather easy to understand.