Change log for Magma V2.24-10 (Released 10/9/2019)

Cyclic Covers

·The MonicModel intrinsic now additionally returns a transformation.

Elliptic Curves over Number Fields

·Some problems with infinite loops in EllipticCurveSearch (involving no suitable ShortVectors] ever being found were fixed).

·The EllipticCurveSearch intrinsic now has parameters to skip the 2-cover reduction and/or Cassels-Tate stage, and also to request more effort be put into searching on 2-covers.

·A bug in the EllipticCurveSearch intrinsic was fixed, that could cause curves over non-quadratic fields with rational j-invariant when these were related to an elliptic curve over Q with 2-conductor neither 4 nor 6. Reported by A. Brumer.

Elliptic Curves over Rationals

·The Cremona database of all elliptic curves of small conductor has been updated to conductor 499,999. Important: ten isogeny classes have been slightly renumbered so that the first curve in the class is the optimal one. The affected classes are: 235470bb, 235746u, 258482a, 265706a, 333270bu, 359282a, 369194a, 375410g, 377034t, and 389774b.

Galois Groups

·Larger degree Tschirnhaus transformations have been allowed in the computation of GaloisSubgroup. Reported by J. Jones.

Group Theory

·A bug in LowIndexSubgroups for pc-groups has been fixed. The bug may have caused subgroup classes to be missed when the index limit was >= 2^30. Bug reported by David Craven.

·A crash in TransitiveGroupIdentification for groups with degree 33 to 47 has been fixed. Bug reported by A-S Elsenhans.

·A bug which caused errors in the maximal subgroups of U(14, 11) as constructed by the intrinsic ClassicalMaximals has been fixed by Derek Holt.

·Various corrections to the maximal subgroups of the classical groups in dimensions 13, 14 and 15 as constructed by the intrinsic ClassicalMaximals have been made by Derek Holt.

Hilbert Modular Forms

·A crash with NewformsOfDegree1 has been fixed.

Hyperelliptic Curves

·A problem with heights on genus 2 curves, involving trying to compute the regular model (when it is not needed), has been fixed. Reported by Sz. Tengely.

Hypergeometric Motives

·A problem with AlphaBetaData has been fixed. Reported by E. Costa.

Hypersurfaces

·A bug with NormalFormOfHypersurfaceSingularity involving incompatible base rings being used internally has been fixed. Reported by F. Rodriguez Villegas.

Incidence Geometry

·The CorrelationGroup intrinsic applied to an incidence geometry was incorrectly returning the automorphism group instead. This has been fixed. Reported by D. Leemans.

Polynomial Rings and Groebner Bases

·Bugs in local polynomial rings with one variable have been fixed. Reported by G. Blanco.

Quadratic Forms

·A bug in the polar group function which caused IsometryGroup to crash has been fixed. Reported by A. Sutherland.