On isometries of conformally invariant metric
  We prove that isometries in a conformally invariant metric of a general domain are quasiconformal. In the particular case of the punctured space, we prove that isometries in this metric are Mobius, thus resolving a conjecture of Ferrand, Martin and Vuorinen [FMV, p. 200] in this particular case. 
Riku Kl\'en, Matti Vuorinen, Xiaohui Zhang
math.CV