751]
235
751.
NOTE ON RIEMANN’S PAPER “VERSUCH EINER ALLGEMEINEN
AUFFASSUNG DER INTEGRATION UND DIFFERENTIATION
[From the Matliematische Annalen, t. xvi. (1880), pp. 81, 82.]
The Editors of Kiemann’s works remark that the paper in question was contained
in a MS. of his student time (dated 14 Jan. 1847) and was probably never intended
for publication: indeed that he would not in later years have recognised the validity
of the principles upon which it is founded. The idea is however a noticeable one:
Riemann considers z x+ll , a function of x + h, expanded in a doubly infinite, necessarily
divergent, series of integer or fractional powers of h, according to the law
%x+h = —' Jc$ v x z. h v , (2)
where the meaning is explained to be that the exponents differ from each other by
integer values, in effect, that v has all the values a + p, a a given integer or fractional
value, and p any integer number from — oo to + qo , zero included.
Riemann deduces a theory of fractional differentiation: but without considering
the question which has always appeared to me to be the great difficulty in such a
theory: what is the real meaning of a complementary function containing an infinity
of arbitrary constants ? or, in other words, what is the arbitrariness of the complemen
tary function of this nature which presents itself in the theory ?
I wish to point out the relation between the paper referred to, and a shoit
paper of my own “On a doubly infinite Series/ Quart. Math. Journ. t. VI. (1851),
pp. 45—47 } [102] : this commences with the remark “ The following completely para
doxical investigation of the properties of the function T (which I have been in possession
* Werke, pp. 331—344.
30—2