Change log for Magma V2.28-12 (Released 6/9/2024)

Character Theory

·A new signature for intrinsic BaseRing has been added - BaseRing of a character table or other sequence of characters returns the minimal cyclotomic field such that all character values in the given sequence can be coerced into the field.

Commutative Algebra

·A small problem in Variety for ideals with non-standard monomial orders has been fixed. Reported by M. Grassl.

·A serious hang and related crash occurring for a certain type of very large Groebner basis computation over the rational field has been fixed. Reported by D. Platt.

Complex Field

·The computation of roots of polynomials over the complex field which involved computing even powers has been improved (so negligible real parts are not included when possible).

Curves

·The functions LPolynomial and ZetaFunction have been fixed for certain problem cases in very small characteristic. Reported by E. Costa.

Elliptic Curves

·Fixed a few places where calling LFunction on an elliptic curve might reassign the generator names of already-existing polynomial rings. Reported by D. Angdinata.

Groups

·A situation where Order applied to infinite matrix groups defined over characteristic zero fields incorrectly returned a finite order has been fixed. Reported by S. Waldron.

·A long-standing bug in defining a pc-group using a power-commutator presentation has been resolved. The bug was reported by D. Roe as a bug in SmallGroupDecoding.

·A problem with matrix group element centralizer computation has been fixed. Bug reported by M. Grassl as a crash in GroupName.

·A complaint about computing the automorphism group of a 01 matrix has been resolved. Reported by M. Grassl.

Lattices

·A crash in IsGLZConjugate involving short vector enumeration has been fixed. Reported by K. Andersen.

Representation Theory

·A crash in CompositionSeries for modules with trivial action and in characteristic zero has been fixed. Reported by L. Scheeren.