When two noninvertible series commute to each other, they have same set of roots of iterates. Most of the results of this paper will be concerned with the problem of which series commute with a given noninvertible series. Our main theorem is a generalization of Lubin's result about isogenies of formal groups.
|Number of pages||10|
|Journal||Transactions of the American Mathematical Society|
|Publication status||Published - 1997|
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