Magma V2.14-7 Patch Notes

Associative Arrays¶

• Some crashes in associative arrays have been fixed. Reported by T. Ekedahl.

Elliptic Curves¶

• Several kinds of runtime and internal errors in CasselsTatePairing have been fixed.

Groups¶

• A bug in the construction of inclusion and projection maps for direct products of sequences of pc-groups has been fixed. Reported by E. O'Brien.
• A problem with HasComplement for finite abelian groups has been fixed. Without this fix, the algorithm would fail in certain examples and trigger a runtime error.
• The function PCGroup now respects the Check parameter properly. Some crashes with large presentations are also fixed. Reported by M. Newman.
• A bug in the solvable quotient has been fixed. Without the fix, AbsolutelyIrreducibleModulesSchur would trigger internal errors for certain inputs. Reported by A. Previtali.

Hyperelliptic Curves¶

• The map returned by TwoSelmerGroup (or TwoSelmerGroupData) is now correct. (Previously, the map sometimes failed to send the group generators to independent elements).

Invariant Theory¶

• The function FundamentalInvariants has been fixed to use the new IrreducibleSecondaryInvariants code in the non-modular case. Reported by G. Kemper.

Local Fields¶

• A bug in the coercion of squences into infinite precision fields has been fixed. Without the fix, the precision in ramified extensions would be too small.
• A bug in Kernel for matrices over p-adic rings has been fixed. Without the fix, Magma would trap internal errors. Reported by G. Chatel.

Number Fields¶

• A bug in the computation of traces of elements in relative extensions of number fields defined by non-monic, non-integral polynomials has been fixed. The old code could return wrong answers. Reported by L. Wilson.
• A bug in the computation of inverses of isomorphisms of absolute simple number fields has been fixed. In certain situations where one of the input fields has a non-monic, non-integral defining polynomial the map returned was wrong. Reported by M. Kirschmer.
• A bug in the internal handling of non-canonically generated prime ideals has been fixed. Without this fix, Magma would dump a lot of information on certain input and terminate with an internal error. Rported by J. Voight.
• A bug in the internal handling of certain non-simple fields has been fixed. The use of sparse cyclotomic fields in quarterion algebras and non-cimple number fields in Decomposition can, under certain circumstances, result in runtime errors. Reported by A. Previtali.
• A problem in the internal precision handling of p-adic completions of number fields has been fixed. Pre-images under the completion of fields were sometimes returned with insufficient precision.
• The function Extends to compare places of number fields was wrong for certain finite places and complex infinite ones.
• The function DecompositionType for abelian extensions can now also handle infinite places.
• A problem in the handling of infinite places in SplittingField has been fixed. Without this fix, certain input would result in infinite loops.

Polynomials¶

• A crash in multivariate GCD has been fixed (called from primary decomposition).
• Crashes in multivariate resultant have been fixed. Reported by M. Watkins.

Quaternion Algebras¶

• A bug in HilbertSymbol, involving ramified extensions, has been fixed.