Pre-set memory limit reached - Gaperror

asked 2020-07-18 06:53:37 -0500

nomadd gravatar image

Hello everyone, I am using a Sage code to compute galois group of a polynomial of degree 24. It is a symbolic polynomial so this code gives possible galois groups. When I run it for lower degrees it gives output but when the polynomial has degree 24 it doesn't compute. Because it computes subgroups of a group of order over 264 million. I know it is very hard to find these groups but i need it. I tried so hard for 3 weeks or more. I use sagemathcell, cocalc and Oracle Virtual Box. I tried so many things but they didn't work. It gives GAPerror: reached pre-set memory limit OR runtime error Gap produced error output, error, variable $sage37 must have a value. I guess the problem is computing conjugacy classes of subgroups. How can I eliminate this Gap error?

P.S1: I am very beginner at Sage. My knowledge about coding, programming etc. is very small. P.S2: I cannot write the code here because it doesn't belong to me. I found it on internet. But if you want to see I can send you the link.

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Comments

1

Can you post the polynomial?

Can you add a link to the code, if it is already posted online somewhere?

In case Ask Sage's anti-spam does not let you post a link, add spaces.

For example: https ://example .com.

slelievre gravatar imageslelievre ( 2020-07-21 17:40:37 -0500 )edit

I cannot post the polynomial here because it is too long. But you can compute with wolfram, sage or magma. Let f(x)=ax^3+bx+c be a cubic polynomial with rational coefficients. Dynatomic polynomial of f(x) is (f^3(x)-x)/(f(x)-x). Here f^3(x) is the composition of f 3 times. I am searching galois group of this dynatomic polynomial.

Here is the code https://github.com/davidkrumm/local-global/blob/master/Failure%20of%20local-global%20principle (https://github.com/davidkrumm/local-g...)

I run this code for galois_candidates(3,3) First 3 corresponds to the period, second corresponds to the degree of f(x). As a sample you can run it for (1,3), (2,3) or for quadratic polynomials (1,2) up to (5,2). If you run for quadratics you can see what I want to compute. Thanks for your help.

nomadd gravatar imagenomadd ( 2020-07-22 08:58:49 -0500 )edit