Re: Complexity of qfisom()

Bill Allombert on Sat, 08 Jan 2022 11:08:10 +0100

[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Re: Complexity of qfisom()

To: pari-dev@pari.math.u-bordeaux.fr
Subject: Re: Complexity of qfisom()
From: Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>
Date: Sat, 8 Jan 2022 11:08:08 +0100
Delivery-date: Sat, 08 Jan 2022 11:08:10 +0100
In-reply-to: <CAGUWgD8qH5kTB-oRgu_1=Qm0aegBLEFf9haprgT_dzevFaJB_Q@mail.gmail.com>
Mail-followup-to: pari-dev@pari.math.u-bordeaux.fr
References: <CAGUWgD8qH5kTB-oRgu_1=Qm0aegBLEFf9haprgT_dzevFaJB_Q@mail.gmail.com>

On Sat, Jan 08, 2022 at 09:36:43AM +0200, Georgi Guninski wrote:
> I read the Fine Manual, but didn't find the answer.
> qfisom(G,H) returns matrix S such that G=S^T H S.
> 
> 1. Must S be permutation matrix up to sign (-1 entry is possible)?

No. S must only be integral with determinant 1 or -1.

Cheers,
Bill

References:
- Complexity of qfisom()
  - From: Georgi Guninski <gguninski@gmail.com>

Prev by Date: Complexity of qfisom()
Next by Date: AVX support for hyperellratpoints
Previous by thread: Complexity of qfisom()
Next by thread: AVX support for hyperellratpoints
Index(es):
- Date
- Thread