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p-rationality

Hecke provides predicates for testing whether an absolute simple number field is quasi-p-rational or p-rational for a given prime p.

Quasi-p-rationality

is_quasi_p_rational Function
julia
is_quasi_p_rational(K::AbsSimpleNumField, p; GRH::Bool = false)

Return whether the number field K is quasi-p-rational.

See also is_p_rational.

Examples

julia
julia> K, = cyclotomic_real_subfield(15);

julia> is_quasi_p_rational(K, 13)
false
source

p-rationality

is_p_rational Function
julia
is_p_rational(K::AbsSimpleNumField, p; GRH::Bool = false)

Return whether the number field K is p-rational at p.

See also is_quasi_p_rational and is_real_cyclotomic_field_p_rational for an improved version that works for real cyclotomic fields and does not require GRH.

Examples

julia
julia> K, = cyclotomic_real_subfield(15);

julia> is_p_rational(K, 13)
false
source

Real cyclotomic fields

For maximal real subfields of cyclotomic fields, a specialized predicate is available.

is_real_cyclotomic_field_p_rational Function
julia
is_real_cyclotomic_field_p_rational(n::Int, p; GRH::Bool = false)

Return whether the maximal real subfield of the cyclotomic field of conductor n is p-rational at p. The conductor n must not be congruent to 2 modulo 4.

See also is_quasi_p_rational and is_p_rational for versions that work for any number field.

Examples

julia
julia> is_real_cyclotomic_field_p_rational(15, 13)
false

julia> p = ZZ(2)^127 - 1;

julia> is_real_cyclotomic_field_p_rational(5, p)
true
source