id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
14300 CyclotomicField's is_isomorphic is mathematically incorrect robharron davidloeffler "If K is a CyclotomicField, then K.is_isomorphic(L) returns true as long as L is a number field and K has an embedding in to L!
{{{
sage: K = CyclotomicField(4)
sage: N = K.extension(x^2-5, 'z')
sage: K.is_isomorphic(N)
True
}}}
Is there a reason that CyclotomicField overrides the generic version of this? I guess one could first do the quick check: if L is a CyclotomicField, then checking they are isomorphic just means checking they are both the nth cyclotomic field (I assume the n is stored somewhere easily accessible)." defect closed critical sage-5.10 number fields fixed CyclotomicField sage-5.10.beta1 Robert Harron Francis Clarke N/A