Mn. Pantyukhina, ASYMPTOTICS OF THE COEFFICIENT OF QUASICONFORMALITY, AND THE BOUNDARY-BEHAVIOR OF A MAPPING OF A BALL, Mathematics of the USSR. Sbornik, 74(2), 1993, pp. 583-591
It is shown that if a quasiconformal automorphism f : B(n) --> B(n) of
the unit ball in R(n) (n greater-than-or-equal-to 2) has coefficient
of quasiconformality K(f)(r) = sup(Absolute value of x less-than-or-eq
ual-to r) k(f, x) in the ball of radius r < 1 with asymptotic growth s
uch that integral1 K(f)(r) dr < infinity, then it has a radial limit a
t almost every point of the boundary. This asymptotic growth of K(f)(r
) is sharp in a certain sense.