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ELLIPTIC CURVES OVER FUNCTION FIELDS

This section involves elliptic curves with coefficients in a function field k(C) where C is a regular projective curve over some field k (usually a number field or a finite field). The commands are largely parallel to those for elliptic curves over the rationals; one can compute local information (Tate's algorithm and so forth), a minimal model, the L-function, the 2-Selmer group, and the Mordell--Weil group. This goes in order of decreasing generality: local information is available for curves over univariate function fields over any exact base field, while at the other extreme Mordell--Weil groups are available only for curves over rational function fields over finite fields for which the associated surface is a rational surface. The generality of many of the commands will be expanded in future releases.  
Acknowledgements
 
An Overview of Relevant Theory
 
Local computations
 
Heights
 
The Torsion Subgroup
 
The Mordell-Weil Group
 
Two-descent
 
The L-function and counting points
 
Action of Frobenius
 
Extended Examples
 
Bibliography







DETAILS

 
An Overview of Relevant Theory

 
Local computations
      BadPlaces(E) : CrvEll -> [ PlcFunElt ]
      Conductor(E) : CrvEll -> DivFunElt
      LocalInformation(E, Pl) : CrvEll[FldFun], PlcFunElt -> Tup, CrvEll
      LocalInformation(E) : CrvEll -> [ < Tup > ]
      KodairaSymbols(E) : CrvEll -> [ <SymKod, RngIntElt> ]
      NumberOfComponents(KS) : SymKod -> RngIntElt
      MinimalModel(E) : CrvEll[FldFunG] -> CrvEll, MapIsoSch
      MinimalDegreeModel(E) : CrvEll[FldFunRat] -> CrvEll, Map, Map
      IsConstantCurve(E) : CrvEll[FldFunRat] -> BoolElt, CrvEll

 
Heights
      NaiveHeight(P) : PtEll -> FldPrElt
      Height(P) : PtEll -> FldRatElt
      LocalHeight(P, Pl) : PtEll, PlcFunElt -> FldPrElt
      HeightPairing(P, Q) : PtEll[FldFunG], PtEll[FldFunG] -> FldRatElt
      HeightPairingMatrix(S) : SeqEnum[PtEll[FldFunG]] -> AlgMatElt
      HeightPairingLattice(S) : [PtEll[FldFunG]] -> AlgMatElt, Map
      Basis(s) : [ PtEll ] -> [ PtEll ], ModMatAlgElt
      Basis(seq,r,disc) : SeqEnum -> SeqEnum
      IsLinearlyDependent(points) : [PtEll] -> BoolElt, ModTupRngElt

 
The Torsion Subgroup
      TorsionSubgroup(E) : CrvEll[FldFunG] -> GrpAb, Map
      TorsionBound(E,n) : CrvEll[FldFunG], RngIntElt -> RngIntElt
      GeometricTorsionBound(E) : CrvEll[FldFunG] -> RngIntElt

 
The Mordell-Weil Group
      RankBounds(E) : CrvEll[FldFunG] -> RngIntElt, RngIntElt
      MordellWeilGroup(E : parameters) : CrvEll[FldFunRat] -> GrpAb, Map
      MordellWeilLattice(E) : CrvEll[FldFunRat] -> Lat, Map
      GeometricMordellWeilLattice(E) : CrvEll[FldFunRat] -> Lat, Map
      Generators(E) : CrvEll[FldFunRat] -> SeqEnum
      Example CrvEllFldFun_rank2 (H105E1)

 
Two-descent
      TwoSelmerGroup(E) : CrvEll[FldFunG] -> GrpAb, MapSch
      TwoDescent(E) : CrvEll[FldFunG] -> SeqEnum[CrvHyp], List[MapSch]
      QuarticMinimize(f) : RngMPolElt[FldFunRat] -> RngMPolElt[FldFunRat]
      Points(C : parameters) : CrvHyp -> [Pt]
      PointsQI(C, H) : Crv, RngIntElt -> [Pt]
      TwoIsogenySelmerGroups(E) : CrvEll[FldFunG] -> GrpAb, GrpAb, MapSch, MapSch

 
The L-function and counting points
      LFunction(E) : CrvEll[FldFunRat] -> RngUPolElt
      LFunction(E, e) : CrvEll[FldFunRat], RngIntElt -> RngUPolElt
      AnalyticRank(E) : CrvEll[FldFunG] -> RngIntElt
      AnalyticInformation(E) : CrvEll[FldFunG] -> Tup
      Example CrvEllFldFun_sha3 (H105E2)
      Example CrvEllFldFun_rank2-continued (H105E3)
      NumberOfPointsOnSurface(E, e) : CrvEll, RngIntElt -> RngIntElt
      NumbersOfPointsOnSurface(E, e) : CrvEll, RngIntElt -> [ RngIntElt ], [ RngIntElt ]
      BettiNumber(E, i) : CrvEll, RngIntElt -> RngIntElt
      CharacteristicPolynomialFromTraces(traces) : [ Fld ] -> RngUPolElt
      CharacteristicPolynomialFromTraces(traces, d, q, i) : [ Fld ], RngIntElt, RngIntElt, RngIntElt -> RngUPolElt, RngUPolElt

 
Action of Frobenius
      Frobenius(P,q) : PtEll[FldFunRat], RngIntElt -> PtEll
      FrobeniusActionOnPoints(s, q : parameters) : [ PtEll ], RngIntElt -> AlgMatElt
      FrobeniusActionOnReducibleFiber(L) : < Tup > -> AlgMatElt
      FrobeniusActionOnTrivialLattice(E) : CrvEll -> AlgMatElt

 
Extended Examples
      Example CrvEllFldFun_ellfunfld1 (H105E4)
      Example CrvEllFldFun_Reductionmodp (H105E5)

 
Bibliography

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