Spin-dependent structure functions of the photon

The implications of the positivity constraint on the presently unknown pola rized structure function of the photon, g(1)(gamma)(x, Q(2)), are studied i n detail. In particular the non-trivial consequences of this constraint, /g (1)(gamma)(x, Q(2))/ less than or equal to F-1(gamma)(x, Q(2)), in the next -to-leading order analysis of g(1)(gamma) are pointed out by employing appr opriate (DIS) factorization schemes related to g(1)(gamma) and rather F-1(g amma) (rather than to F-2(gamma)). (C) 2001 Elsevier Science B.V. All right s reserved.