We obtained sufficient conditions for existence of fixed points of involutions in CAT$(0)$ spaces. Convergence results of Mann and Ishikawa iterates of weakly contractive mappings are also proved.
"Fixed point in CAT(0) spaces." Funct. Approx. Comment. Math. 48 (1) 51 - 59, March 2013. https://doi.org/10.7169/facm/2013.48.1.5