https://en.wikipedia.org/wiki/Conductor_of_an_elliptic_curve Conductor of an elliptic curve (抜粋) Contents 1 History 2 Definition 3 Ogg's formula 4 Global conductor 5 References 6 Further reading
History The conductor of an elliptic curve over a local field was implicitly studied (but not named) by Ogg (1967) in the form of an integer invariant ε+δ which later turned out to be the exponent of the conductor.
The conductor of an elliptic curve over the rationals was introduced and named by Weil (1967) as a constant appearing in the functional equation of its L-series, analogous to the way the conductor of a global field appears in the functional equation of its zeta function. He showed that it could be written as a product over primes with exponents given by order(Δ) ? μ + 1, which by Ogg's formula is equal
