We show that the Yao graph Y4 in the L2 metric is a spanner with stretch factor 8√2(29 + 23√2.

doi.org/10.1007/978-3-642-17514-5_38
School of Mathematics and Statistics

Bose, P, Damian, M. (Mirela), Douïeb, K. (Karim), O'Rourke, J. (Joseph), Seamone, B. (Ben), Smid, M, & Wuhrer, S. (Stefanie). (2010). π/2-angle Yao graphs are spanners. doi:10.1007/978-3-642-17514-5_38