We analise periodic functions (mod r), keeping Cauchy multiplication as the basic tool, and pay particular attention to even functions (mod r) having the property f(n) = f((n,r)) for all n. We provide some new aspects into the Hilbert space structure of even functions (mod r) and make use of linera transformations to interpret the known number-theoretic formulae involving solutions of congruences.
@article{urn:eudml:doc:42426, title = {Cauchy multiplication and periodic functions (mod r).}, journal = {Collectanea Mathematica}, volume = {42}, year = {1991}, pages = {33-44}, zbl = {0769.11001}, mrnumber = {MR1181060}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:42426} }
Haukkanen, Pentti; Sivaramakrishnan, R. Cauchy multiplication and periodic functions (mod r).. Collectanea Mathematica, Tome 42 (1991) pp. 33-44. http://gdmltest.u-ga.fr/item/urn:eudml:doc:42426/