Change log for Magma V2.28-7 (Released 8/3/2024)

Algebraic Curves

·A spurious debug print in CurveQuotient has been removed. Reported by D. Zureick-Brown.

Commutative Algebra

·A crash in VarietySize for ideals having multiple components has been fixed. Reported by M. Grassl.

Finite Fields

·A crash when computing discrete logarithms in several finite fields with differing degrees has been fixed. Reported by E. O'Brien.

·The function Log(b, e) for finite field elements has been improved in the case that the base b lies in a proper subfield (by computing the logarithm in the subfield).

Finitely Presented Groups

·A problem with IsInfiniteFPGroup for an FP-group with one generator has been fixed. Reported by M. Grassl.

Linear Programming

·A crash in MinimalIntegerSolution has been fixed. Reported by A. Munemasa.

Matrix Groups

·Fixed bug in RecognizeClassical where QuasisimpleMatrixGroup ("2L247", 24, 7) was identified incorrectly as SL(24, 7). Identifed by E. O'Brien and fixed by A. Niemeyer.

·Two new functions ProjectiveClassicalIsConjugate and ProjectiveClassicalCentraliser which decide conjugacy and construct centraliser in the central quotient of a classical group. Prepared by D. Holt and E. O'Brien.

·The algorithm to compute element centralisers in unitary groups has been greatly improved in large cases by avoiding a hard discrete logarithm problem. Issue reported by E. O'Brien and improvement supplied by G. de Franceschi.

Permutation Groups

·A crash in Subgroups of non-standard permutation groups has been fixed. Reported by M. Rodgers.

Representation Theory

·A crash in IsIrreducible for G-modules defined over number fields has been fixed. Reported by S. Humphries.