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On a
linear functional equation for formal power series. |
On a linear functional equation for formal power
series.
Jointly written with LUDWIG REICH.
Sitzungsberichte der Österreichischen Akademie der
Wissenschaften, Abt. II, 210:85-134, 2001.
Abstract: Let ρ be a primitive j0 -th
complex root of 1, C[[x]] the ring of formal power series in
x over ℂ, and let a(x), b(x) in C[[x]]. We study
the two equations
and
for φ in C[[x]], which occurred in connection with an
interesting and important special case when dealing with the
problem of a covariant embedding of (L) with respect to an
iteration group. (See H. Fripertinger and L. Reich. On
covariant embeddings of a linear functional equation with respect
to an analytic iteration group. Accepted for publication in the
International Journal of Bifurcation and Chaos.) We
describe necessary and sufficient conditions for finding nontrivial
solutions of (Lh) and for finding solutions of (L) in
the form of "cyclic" functional equations for a and b. Then we
describe the set of all solutions of these functional equations and
present different representations of their general solutions.
harald.fripertinger "at" uni-graz.at, January 12,
2012
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On a
linear functional equation for formal power series. |
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