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The covariants of V 7

In document Invariants of binary forms (Page 153-166)

First we create a matrix with the evaluations of the 147 covariants from Tables

5.4and5.5at 2750 random integers.

Next we show that the 147 covariants generate C(V

7

)

d,m

with d ≤ 23 and

m ≤ 15. For each d ≤ 24 and m ≤ 15 we do the following: we construct all

possible monomials of degree d and order m spanned by the 147 covariants and

evaluate them at random integers (using the matrix we just created). These

monomials will span C(V

7

)

d,m

if their evaluation matrix has the rank equal to

called mon{deg,ord} which returns a list of all covariants degree deg and order

ord as monomials of degree deg spanned by the above 147 covariants.

In[]:=listdeg={{1,7},{2,2},{2,6},{2,10},{3,3},{3,5},{3,7},{3,9},{3,11}, {3,15},{4,0},{4,4},{4,4},{4,6},{4,8},{4,8},{4,10},{4,14},{5,1},{5,3}, {5,3},{5,5},{5,5},{5,7},{5,7},{5,9},{5,9},{5,13},{6,2},{6,2},{6,2}, {6,4},{6,4},{6,6},{6,6},{6,8},{6,8},{6,12},{7,1},{7,1},{7,1},{7,3}, {7,3},{7,5},{7,5},{7,5},{7,5},{7,7},{7,7},{7,11},{8,0},{8,0},{8,0}, {8,2},{8,2},{8,2},{8,4},{8,4},{8,4},{8,6},{8,6},{8,6},{8,10},{9,1}, {9,1},{9,1},{9,3},{9,3},{9,3},{9,3},{9,3},{9,5},{9,5},{9,9},{10,2}, {10,2},{10,2},{10,2},{10,4},{10,4},{10,4},{10,4},{10,8},{11,1}, {11,1},{11,1},{11,1},{11,1},{11,3},{11,3},{11,3},{11,7},{12,0},{12,0}, {12,0},{12,0},{12,0},{12,0},{12,2},{12,2},{12,2},{12,2},{12,2},{12,2}, {12,6},{13,1},{13,1},{13,1},{13,1},{13,1},{13,1},{13,1},{13,3},{13,5}, {14,0},{14,0},{14,0},{14,0},{14,4},{14,4},{15,1},{15,1},{15,1},{15,3}, {16,0},{16,0},{16,2},{16,2},{16,2},{17,1},{17,1},{18,0},{18,0},{18,0}, {18,0},{18,0},{18,0},{18,0},{18,0},{18,0},{19,1},{20,0},{22,0},{22,0}, {23,1},{26,0},{30,0}}; In[]:=listgen={FF,LL,CHI,HH,RR,C35,C37,Epsilon,Gamm,TT,Inv4,PP,C44,C46, Delta,C48,C410,Zet,C51,C531,C532,GG,C55,ETA,C57,C591,C592,C513,Tau, C621,C622,C641,C642,C661,C662,Bet,C68,C612,Alpha,C711,C712,C731,C732, Theta,C751,C752,C753,C771,C772,Cov711,C801,C802,C803,C821,C822,C823,MU, C841,C842,Lambda,C861,C862,C810,C911,C912,C913,QQ,C931,C932,C933,C934, C951,C952,C99,NU,C1021,C1022,C1023,C1041,C1042,C1043,C1044,C108,C1111, C1112,C1113,C1114,C1115,PHI,C1131,C1132,C117,Rbig,C1201,C1202,C1203, C1204,C1205,C1221,C1222,C1223,C1224,C1225,C1226,C126,RO,C1311,C1312, C1313,C1314,C1315,C1316,C133,C135,C1401,C1402,C1403,C1404,PSI,C1441, C1511,C1512,C1513,C153,C1601,C1602,Sigma,C1621,C1622,Omega,C1711,C1801, C1802,C1803,C1804,C1805,C1806,C1807,C1808,C1809,C191,C201,C2201,C2202, C231,C260,C300}; In[]:=mon[md_,j_]:= mon[md,j]=If[md=={0,0},1,If[md[[1]]<0||md[[2]]<0,{}, Flatten[Table[listgen[[i]]mon[md-listdeg[[i]],i],{i,1,j}]]]]

Here we show that the 147 covariants generate C(V

7

)

d,m

with d ≤ 24 and

m ≤ 15:

In[]:= Timing[ For[deg=2,deg<24,deg++,ord=1; While[ord<16, symm=SymTensor[7,deg]/.Table[v[i]->0,{i,16,1000}]; kk=Coefficient[symm,v[ord]]+1; If[kk!=1,

Print[{deg,ord},": the vector space of covs has dimension",kk-1]; ss=mon[{deg,ord},147];

If[ss!={},

tt=Intersection[ss,listgen]; If[tt!={},

ss1=Complement[ss,tt];

eval1 = Table[ss1 /.Table[listgen[[j]]->Matr[[k]][[j]][[1]], {j,1,Length[Matr[[k]]]}],{k,1,kk}];

rk1=If[ss1=={},0,MatrixRank[eval1,Modulus->32003]]; Print["-- the subpace spanned by covs of degree < ", deg,

" has dim >=", rk1];

Print["-- there are ", Length[tt], " gens of degree ", deg]; eval=Table[ss/.Table[listgen[[j]]->Matr[[k]][[j]][[1]],

rk=MatrixRank[eval,Modulus->32003];

Print["-- the subpace spanned by covs of degree <= ", deg, " has dim >=", rk], If[Length[ss]>3000,DIM=kk-1; dd1=RandomSample[ss,kk+10]; dd2=Complement[ss,dd1]; eval=Table[dd1/.Table[listgen[[j]]->Matr[[k]][[j]][[1]], {j,1,Length[Matr[[k]]]}],{k,1,kk}]; eval1=ColumnEchelon[eval]; rk1=MatrixRank[eval1,Modulus->32003]; rk=rk1; While[rk!=DIM, AA=Table[RandomInteger[{-10,10}],{i,1,50}]; uu=RandomSample[dd2,50].AA; evaluu=Table[uu/.Table[listgen[[j]]->Matr[[k]][[j]][[1]], {j,1,Length[Matr[[k]]]}],{k,1,kk}]; eval=Table[Join[eval1[[i]],{evaluu[[i]]}],{i,1,kk}]; eval=Mod[eval,32003]; rk=MatrixRank[eval,Modulus->32003]; If[rk>rk1,eval1=eval;rk1=rk]];

Print["-- the subpace spanned by covs of degree < ", deg, " has dim >=", rk],

eval=Table[ss/.Table[listgen[[j]]->Matr[[k]][[j]][[1]], {j,1,Length[Matr[[k]]]}],{k,1,kk}];

rk=MatrixRank[eval,Modulus->32003];

Print["-- the subpace spanned by covs of degree < ", deg, " has dim >=", rk]]]]]; ord++]

]]

{2,2}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 2 has dim >=0 -- there are 1 gens of degree 2

-- the subpace spanned by covs of degree <= 2 has dim >=1 {2,6}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 2 has dim >=0 -- there are 1 gens of degree 2

-- the subpace spanned by covs of degree <= 2 has dim >=1 {2,10}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 2 has dim >=0 -- there are 1 gens of degree 2

-- the subpace spanned by covs of degree <= 2 has dim >=1 {2,14}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 2 has dim >=1 {3,3}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 3 has dim >=0 -- there are 1 gens of degree 3

-- the subpace spanned by covs of degree <= 3 has dim >=1 {3,5}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 3 has dim >=0 -- there are 1 gens of degree 3

-- the subpace spanned by covs of degree <= 3 has dim >=1 {3,7}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 3 has dim >=0 -- there are 1 gens of degree 3

-- the subpace spanned by covs of degree <= 3 has dim >=1 {3,9}: the vector space of covs has dimension 2

-- the subpace spanned by covs of degree < 3 has dim >=1 -- there are 1 gens of degree 3

-- the subpace spanned by covs of degree <= 3 has dim >=2 {3,11}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 3 has dim >=0 -- there are 1 gens of degree 3

-- the subpace spanned by covs of degree <= 3 has dim >=1 {3,13}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 3 has dim >=1 {3,15}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 3 has dim >=0 -- there are 1 gens of degree 3

-- the subpace spanned by covs of degree <= 3 has dim >=1 {4,4}: the vector space of covs has dimension 3

-- the subpace spanned by covs of degree < 4 has dim >=1 -- there are 2 gens of degree 4

-- the subpace spanned by covs of degree <= 4 has dim >=3 {4,6}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 4 has dim >=0 -- there are 1 gens of degree 4

-- the subpace spanned by covs of degree <= 4 has dim >=1 {4,8}: the vector space of covs has dimension 3

-- the subpace spanned by covs of degree < 4 has dim >=1 -- there are 2 gens of degree 4

-- the subpace spanned by covs of degree <= 4 has dim >=3 {4,10}: the vector space of covs has dimension 2

-- the subpace spanned by covs of degree < 4 has dim >=1 -- there are 1 gens of degree 4

-- the subpace spanned by covs of degree <= 4 has dim >=2 {4,12}: the vector space of covs has dimension 3

-- the subpace spanned by covs of degree < 4 has dim >=3 {4,14}: the vector space of covs has dimension 2

-- the subpace spanned by covs of degree < 4 has dim >=1 -- there are 1 gens of degree 4

-- the subpace spanned by covs of degree <= 4 has dim >=2 {5,1}: the vector space of covs has dimension 1

-- the subpace spanned by covs of degree < 5 has dim >=0 -- there are 1 gens of degree 5

-- the subpace spanned by covs of degree <= 5 has dim >=1 {5,3}: the vector space of covs has dimension 2

-- the subpace spanned by covs of degree < 5 has dim >=0 -- there are 2 gens of degree 5

-- the subpace spanned by covs of degree <= 5 has dim >=2 {5,5}: the vector space of covs has dimension 3

-- the subpace spanned by covs of degree < 5 has dim >=1 -- there are 2 gens of degree 5

-- the subpace spanned by covs of degree <= 5 has dim >=3 {5,7}: the vector space of covs has dimension 4

-- the subpace spanned by covs of degree < 5 has dim >=2 -- there are 2 gens of degree 5

-- the subpace spanned by covs of degree <= 5 has dim >=4 {5,9}: the vector space of covs has dimension 4

-- the subpace spanned by covs of degree < 5 has dim >=2 -- there are 2 gens of degree 5

-- the subpace spanned by covs of degree <= 5 has dim >=4 {5,11}: the vector space of covs has dimension 5

-- the subpace spanned by covs of degree < 5 has dim >=5 {5,13}: the vector space of covs has dimension 4

-- there are 1 gens of degree 5

-- the subpace spanned by covs of degree <= 5 has dim >=4 {5,15}: the vector space of covs has dimension 5

-- the subpace spanned by covs of degree < 5 has dim >=5 {6,2}: the vector space of covs has dimension 4

-- the subpace spanned by covs of degree < 6 has dim >=1 -- there are 3 gens of degree 6

-- the subpace spanned by covs of degree <= 6 has dim >=4 {6,4}: the vector space of covs has dimension 2

-- the subpace spanned by covs of degree < 6 has dim >=0 -- there are 2 gens of degree 6

-- the subpace spanned by covs of degree <= 6 has dim >=2 {6,6}: the vector space of covs has dimension 7

-- the subpace spanned by covs of degree < 6 has dim >=5 -- there are 2 gens of degree 6

-- the subpace spanned by covs of degree <= 6 has dim >=7 {6,8}: the vector space of covs has dimension 5

-- the subpace spanned by covs of degree < 6 has dim >=3 -- there are 2 gens of degree 6

-- the subpace spanned by covs of degree <= 6 has dim >=5 {6,10}: the vector space of covs has dimension 8

-- the subpace spanned by covs of degree < 6 has dim >=8 {6,12}: the vector space of covs has dimension 7

-- the subpace spanned by covs of degree < 6 has dim >=6 -- there are 1 gens of degree 6

-- the subpace spanned by covs of degree <= 6 has dim >=7 {6,14}: the vector space of covs has dimension 9

-- the subpace spanned by covs of degree < 6 has dim >=9 {7,1}: the vector space of covs has dimension 3

-- the subpace spanned by covs of degree < 7 has dim >=0 -- there are 3 gens of degree 7

-- the subpace spanned by covs of degree <= 7 has dim >=3 {7,3}: the vector space of covs has dimension 4

-- the subpace spanned by covs of degree < 7 has dim >=2 -- there are 2 gens of degree 7

-- the subpace spanned by covs of degree <= 7 has dim >=4 {7,5}: the vector space of covs has dimension 7

-- the subpace spanned by covs of degree < 7 has dim >=3 -- there are 4 gens of degree 7

-- the subpace spanned by covs of degree <= 7 has dim >=7 {7,7}: the vector space of covs has dimension 9

-- the subpace spanned by covs of degree < 7 has dim >=7 -- there are 2 gens of degree 7

-- the subpace spanned by covs of degree <= 7 has dim >=9 {7,9}: the vector space of covs has dimension 10

-- the subpace spanned by covs of degree < 7 has dim >=10 {7,11}: the vector space of covs has dimension 11

-- the subpace spanned by covs of degree < 7 has dim >=10 -- there are 1 gens of degree 7

-- the subpace spanned by covs of degree <= 7 has dim >=11 {7,13}: the vector space of covs has dimension 13

-- the subpace spanned by covs of degree < 7 has dim >=13 {7,15}: the vector space of covs has dimension 12

-- the subpace spanned by covs of degree < 7 has dim >=12 {8,2}: the vector space of covs has dimension 3

-- the subpace spanned by covs of degree < 8 has dim >=0 -- there are 3 gens of degree 8

-- the subpace spanned by covs of degree <= 8 has dim >=3 {8,4}: the vector space of covs has dimension 10

-- the subpace spanned by covs of degree < 8 has dim >=7 -- there are 3 gens of degree 8

-- the subpace spanned by covs of degree <= 8 has dim >=10 {8,6}: the vector space of covs has dimension 9

-- the subpace spanned by covs of degree < 8 has dim >=6 -- there are 3 gens of degree 8

-- the subpace spanned by covs of degree <= 8 has dim >=9 {8,8}: the vector space of covs has dimension 16

-- the subpace spanned by covs of degree < 8 has dim >=16 {8,10}: the vector space of covs has dimension 14

-- the subpace spanned by covs of degree < 8 has dim >=13 -- there are 1 gens of degree 8

-- the subpace spanned by covs of degree <= 8 has dim >=14 {8,12}: the vector space of covs has dimension 19

-- the subpace spanned by covs of degree < 8 has dim >=19 {8,14}: the vector space of covs has dimension 17

-- the subpace spanned by covs of degree < 8 has dim >=17 {9,1}: the vector space of covs has dimension 4

-- the subpace spanned by covs of degree < 9 has dim >=1 -- there are 3 gens of degree 9

-- the subpace spanned by covs of degree <= 9 has dim >=4 {9,3}: the vector space of covs has dimension 10

-- the subpace spanned by covs of degree < 9 has dim >=5 -- there are 5 gens of degree 9

-- the subpace spanned by covs of degree <= 9 has dim >=10 {9,5}: the vector space of covs has dimension 13

-- the subpace spanned by covs of degree < 9 has dim >=11 -- there are 2 gens of degree 9

-- the subpace spanned by covs of degree <= 9 has dim >=13 {9,7}: the vector space of covs has dimension 17

-- the subpace spanned by covs of degree < 9 has dim >=17 {9,9}: the vector space of covs has dimension 21

-- the subpace spanned by covs of degree < 9 has dim >=20 -- there are 1 gens of degree 9

-- the subpace spanned by covs of degree <= 9 has dim >=21 {9,11}: the vector space of covs has dimension 24

-- the subpace spanned by covs of degree < 9 has dim >=24 {9,13}: the vector space of covs has dimension 25

-- the subpace spanned by covs of degree < 9 has dim >=25 {9,15}: the vector space of covs has dimension 29

-- the subpace spanned by covs of degree < 9 has dim >=29 {10,2}: the vector space of covs has dimension 12

-- the subpace spanned by covs of degree < 10 has dim >=8 -- there are 4 gens of degree 10

-- the subpace spanned by covs of degree <= 10 has dim >=12 {10,4}: the vector space of covs has dimension 13

-- the subpace spanned by covs of degree < 10 has dim >=9 -- there are 4 gens of degree 10

-- the subpace spanned by covs of degree <= 10 has dim >=13 {10,6}: the vector space of covs has dimension 23

-- the subpace spanned by covs of degree < 10 has dim >=23 {10,8}: the vector space of covs has dimension 23

-- the subpace spanned by covs of degree < 10 has dim >=22 -- there are 1 gens of degree 10

{10,10}: the vector space of covs has dimension 34

-- the subpace spanned by covs of degree < 10 has dim >=34 {10,12}: the vector space of covs has dimension 31

-- the subpace spanned by covs of degree < 10 has dim >=31 {10,14}: the vector space of covs has dimension 40

-- the subpace spanned by covs of degree < 10 has dim >=40 {11,1}: the vector space of covs has dimension 8

-- the subpace spanned by covs of degree < 11 has dim >=3 -- there are 5 gens of degree 11

-- the subpace spanned by covs of degree <= 11 has dim >=8 {11,3}: the vector space of covs has dimension 16

-- the subpace spanned by covs of degree < 11 has dim >=13 -- there are 3 gens of degree 11

-- the subpace spanned by covs of degree <= 11 has dim >=16 {11,5}: the vector space of covs has dimension 24

-- the subpace spanned by covs of degree < 11 has dim >=24 {11,7}: the vector space of covs has dimension 31

-- the subpace spanned by covs of degree < 11 has dim >=30 -- there are 1 gens of degree 11

-- the subpace spanned by covs of degree <= 11 has dim >=31 {11,9}: the vector space of covs has dimension 38

-- the subpace spanned by covs of degree < 11 has dim >=38 {11,11}: the vector space of covs has dimension 43

-- the subpace spanned by covs of degree < 11 has dim >=43 {11,13}: the vector space of covs has dimension 49

-- the subpace spanned by covs of degree < 11 has dim >=49 {11,15}: the vector space of covs has dimension 52

-- the subpace spanned by covs of degree < 11 has dim >=52 {12,2}: the vector space of covs has dimension 12

-- the subpace spanned by covs of degree < 12 has dim >=6 -- there are 6 gens of degree 12

-- the subpace spanned by covs of degree <= 12 has dim >=12 {12,4}: the vector space of covs has dimension 29

-- the subpace spanned by covs of degree < 12 has dim >=29 {12,6}: the vector space of covs has dimension 33

-- the subpace spanned by covs of degree < 12 has dim >=32 -- there are 1 gens of degree 12

-- the subpace spanned by covs of degree <= 12 has dim >=33 {12,8}: the vector space of covs has dimension 48

-- the subpace spanned by covs of degree < 12 has dim >=48 {12,10}: the vector space of covs has dimension 49

-- the subpace spanned by covs of degree < 12 has dim >=49 {12,12}: the vector space of covs has dimension 65

-- the subpace spanned by covs of degree < 12 has dim >=65 {12,14}: the vector space of covs has dimension 64

-- the subpace spanned by covs of degree < 12 has dim >=64 {13,1}: the vector space of covs has dimension 14

-- the subpace spanned by covs of degree < 13 has dim >=7 -- there are 7 gens of degree 13

-- the subpace spanned by covs of degree <= 13 has dim >=14 {13,3}: the vector space of covs has dimension 26

-- the subpace spanned by covs of degree < 13 has dim >=25 -- there are 1 gens of degree 13

-- the subpace spanned by covs of degree <= 13 has dim >=26 {13,5}: the vector space of covs has dimension 39

-- the subpace spanned by covs of degree < 13 has dim >=38 -- there are 1 gens of degree 13

-- the subpace spanned by covs of degree <= 13 has dim >=39 {13,7}: the vector space of covs has dimension 53

-- the subpace spanned by covs of degree < 13 has dim >=53 {13,9}: the vector space of covs has dimension 62

-- the subpace spanned by covs of degree < 13 has dim >=62 {13,11}: the vector space of covs has dimension 74

-- the subpace spanned by covs of degree < 13 has dim >=74 {13,13}: the vector space of covs has dimension 83

-- the subpace spanned by covs of degree < 13 has dim >=83 {13,15}: the vector space of covs has dimension 91

-- the subpace spanned by covs of degree < 13 has dim >=91 {14,2}: the vector space of covs has dimension 30

-- the subpace spanned by covs of degree < 14 has dim >=30 {14,4}: the vector space of covs has dimension 37

-- the subpace spanned by covs of degree < 14 has dim >=35 -- there are 2 gens of degree 14

-- the subpace spanned by covs of degree <= 14 has dim >=37 {14,6}: the vector space of covs has dimension 62

-- the subpace spanned by covs of degree < 14 has dim >=62 {14,8}: the vector space of covs has dimension 68

-- the subpace spanned by covs of degree < 14 has dim >=68 {14,10}: the vector space of covs has dimension 91

-- the subpace spanned by covs of degree < 14 has dim >=91 {14,12}: the vector space of covs has dimension 95

-- the subpace spanned by covs of degree < 14 has dim >=95 {14,14}: the vector space of covs has dimension 116

-- the subpace spanned by covs of degree < 14 has dim >=116 {15,1}: the vector space of covs has dimension 20

-- the subpace spanned by covs of degree < 15 has dim >=17 -- there are 3 gens of degree 15

-- the subpace spanned by covs of degree <= 15 has dim >=20 {15,3}: the vector space of covs has dimension 42

-- the subpace spanned by covs of degree < 15 has dim >=41 -- there are 1 gens of degree 15

-- the subpace spanned by covs of degree <= 15 has dim >=42 {15,5}: the vector space of covs has dimension 62

-- the subpace spanned by covs of degree < 15 has dim >=62 {15,7}: the vector space of covs has dimension 80

-- the subpace spanned by covs of degree < 15 has dim >=80

In document Invariants of binary forms (Page 153-166)