Re: all divisors of a cyclotomic integer

[John Cremona <john.cremona@gmail.com>]

I think that if a user thinks that some utility function would be useful, and it is easy to provide, then the software authors should consider adding it even if they themselves cannot think of an application.

In my code for computing bianchi modular forms (which does not use libpari as I am not clever enough to use it) I have a lot of ideal utilities, and listing all ideal divisors of an ideal is one of them.

So I vote to add such a function.

John

On Thu, 1 Sept 2022, 20:26 Bill Allombert, <Bill.Allombert@math.u-bordeaux.fr> wrote:

On Thu, Sep 01, 2022 at 07:35:58AM -0400, Max Alekseyev wrote:
> Dear Bill,
>
> Thank you for checking this. I somehow messed up conversion into
> polynomials, which worked for small examples but not large ones.
> On a related note, would it make sense to provide fordiv / divisors
> functions for number fields?

We could add a function idealdivisors that returns the list of divisors of
an ideal, but there seems little use for that.

What is your applications ? Number field elements have usually an infinite
number of divisors due to units.

Cheers,
Bill