Universal ratios among corrections-to-scaling amplitudes in the large-n limit

form f, =A, ~ (r'( I +a, ( r( ), where r =(T —T, )/T, . The correction-to-scaling amplitudes a, are calculated to leading order in 1/n for 2 ( d (4, and the universality of' their ratios is explicitly shown. The effective exponents it, «r — X, —a, A~r~a violate the thermodynamic scaling laws already at this leading order. The amplitudes a, have singularities (as functions of d) at the dimensionalities dt =2+4/I, l =3, 4, 5, . . . . Above T, , the specific heat and the susceptibility correction amplitudes a,.+ and a~ are discontinuous at d& and at d» (I «2), respectively. Below T„ the magnetization and the stiffness correction amplitudes are zero, aM =a =0, while a, . diverges at d2&+1 (l «1) but is continuous at d» (in particular at d =3). Results are also given for universal ratios among corrections-to-scaling amplitudes for the dependence of thermodynamic functions on the magnetization at T = T, , and at a nonzero field.