H. Tanigawa, DISCRETENESS OF FINITE-DIMENSIONAL TEICHMULLER-SPACES IN THE UNIVERSAL TEICHMULLER SPACE, Tohoku Mathematical Journal, 46(1), 1994, pp. 135-140
The universal Teichmuller space contains all Teichmuller spaces of hyp
erbolic Riemann surfaces. We shall investigate how the Teichmuller spa
ces of punctured spheres vary in the universal Teichmuller space when
the base points change.