Change log for Magma V2.28-9 (Released 31/5/2024)

Algebraic Function Fields

·RationalFunction for elements of non simple function fields now ensures the element has known coefficients rather than returning 0. Reported by F. Hess.

·Applying Automorphisms to elements with a product representation no longer computes coefficients of the element.

·Taking preimages of the identity automorphism has also been fixed. Reported and fixed by F. Hess.

Algebraic Number Fields

·Fixes have been made to recent improvements in MaximalOrder computations. Reported by J. Schleucher.

·Decomposition of finite places of coefficient fields in extensions has been enabled. Reported by J. Schleucher.

Arithmetic Geometry

·Some fixes have been to the package which computes invariants or twists of genus 3 curves. Supplied by R. Lercier.

·Fixes have been made in the code for determining a bound for the difference between naive and canonical height on genus 2 Jacobians. Fix supplied by M. Stoll and S. Muller.

Galois Groups

·Precision handling has been improved in SplittingField so that the valuation of the discriminant can be accurately determined. Reported by J. Schleucher.

·User provided primes using the Prime parameter to GaloisGroup are now checked to be unramified. If a user given prime is ramified, another prime will be selected for the computation. Reported by J. Schleucher.

Lie Algebras

·A crash in Algebra applied to a universal enveloping algebra has been fixed. Reported by E. Assaf.

Local Fields

·Increased error checking of the map given as the second argument to RelativeField is now done. Reported by J. Schleucher.

Permutation Groups

·Computing the quotient of permutations groups by quo where N is the trivial subgroup has been fixed so that the result is the degree reduction of G (consistent with previous behaviour).