Published online by Cambridge University Press: 20 November 2018
Let be an associative algebra over the field
and let
be the group of all automorphisms and anti-automorphisms of
which leave
elementwise invariant. A function Fwith domain
and range contained in
is called an intrinsic functionon
if (i)
for each Ω in
and (ii) F(ΩZ) = ΩF(Z) for every Z in
.
Rinehart (5) has introduced and motivated the study of the class of intrinsic functions on , and has characterized these functions for the cases in which
is the algebra
of real quaternions, the algebra
of n × ncomplex matrices, or the algebra
of n× nreal matrices (5; 6). The algebras listed above, along with the algebra
of n × nquaternion matrices, constitute the full list of possibilities for the simple direct summands of any semi-simple algebra over
or
; see (2).