Innerness criterion for twisted derivations when the conductor is
Innerness criterion for twisted derivations when the conductor is
Let be the th cyclotomic number field with , where and is an odd rational prime, and let . Let with , let and , and let be the coefficient matrix from the preceding determinant conjecture. For a -derivation , write
Innerness conjecture. Under the hypotheses of the determinant conjecture, if and , then is inner if and only if
In particular, divisibility of every by , and even divisibility of every by , implies innerness. If and , replace the denominator by ; in all other cases is always inner. This is the proposed necessary-and-sufficient characterization of inner twisted derivations for this conductor form; together with the determinant claim, it is intended to distinguish the cases where outer derivations can occur.
Progress summary
Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.
Sources & referencesView supporting material
Primary source
Praveen Manju and Rajendra Kumar Sharma, “Twisted Derivations in Algebraic Number Fields”, arXiv:2412.03507 (2026).
Solutions 0
Sign in to submit a solution.
No solutions have been posted yet.