- Parameterizing group-polynomial in terms of the roots of the generator
- Minimal polynomial
The Main Result 2.3
The explicit expression for the group-polynomial coefficient functions
fricas
groupPolyCoeff(i) == (-1)^(i+n+1)*sum([exp(r[j])/product([r[j]-r[m] for m in 1..n | j~=m])*f(i,j) for j in 1..n])
Type: Void
fricas
f(i,j) == sum [ product x for x in choose([r[q]::Expression Integer for q in 1..n|q~=j],n-i-1)]
Type: Void
Example (polynomial of degree 1)
fricas
n:=1
fricas
groupPolyCoeff(0)
fricas
Compiling function product with type List(Polynomial(Integer)) ->
Polynomial(Integer)
fricas
Compiling function choose with type (List(Expression(Integer)),
Integer) -> List(List(Expression(Integer)))
fricas
Compiling function product with type List(Expression(Integer)) ->
Expression(Integer)
fricas
Compiling function f with type (NonNegativeInteger,PositiveInteger)
-> Expression(Integer)
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Compiling function groupPolyCoeff with type NonNegativeInteger ->
Expression(Integer)
Type: Expression(Integer)
- Polynomial of degree 2
fricas
n:=2
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eq2_1:= m[X]=(x-r[1])*(x-r[2])
Type: Equation(Polynomial(Integer))
fricas
eq2_2:= exp(X)=g[0]+g[1]*X
Type: Equation(Expression(Integer))
fricas
eq2_3a:= g[0]=groupPolyCoeff(0)
Type: Equation(Expression(Integer))
fricas
eq2_3b:= g[1]=groupPolyCoeff(1)
fricas
Compiling function f with type (PositiveInteger,PositiveInteger) ->
Expression(Integer)
fricas
Compiling function groupPolyCoeff with type PositiveInteger ->
Expression(Integer)
Type: Equation(Expression(Integer))
Example 3.1 (Tri-gonometry)
fricas
eval(eq2_1,[r[2]=-r[1]])
Type: Equation(Polynomial(Integer))
fricas
eq2_4:= eval(eval(eq2_2,[eq2_3a,eq2_3b]),r[2]=-r[1])
Type: Equation(Expression(Integer))
fricas
htrigs rhs %
Type: Expression(Integer)
- Polynomial of degree 3
fricas
n:=3
fricas
eq3_1:= m[X]=(x-r[1])*(x-r[2])*(x-r[3])
Type: Equation(Polynomial(Integer))
fricas
eq3_2:= exp(X)=g[0]+g[1]*X+g[2]*X^2
Type: Equation(Expression(Integer))
fricas
eq3_3a:= g[0]=groupPolyCoeff(0)
Type: Equation(Expression(Integer))
fricas
eq3_3b:= g[1]=groupPolyCoeff(1)
Type: Equation(Expression(Integer))
fricas
eq3_3c:= g[2]=groupPolyCoeff(2)
Type: Equation(Expression(Integer))
Example 4.1
fricas
eval(eq3_1,[r[2]=-r[1],r[3]=0])
Type: Equation(Polynomial(Integer))
fricas
eq3_4:= eval(eval(eq3_2,[eq3_3a,eq3_3b,eq3_3c]),[r[2]=-r[1],r[3]=0])
Type: Equation(Expression(Integer))
fricas
htrigs rhs eq3_4
Type: Expression(Integer)
Comment 4.2 (Rescaled enomorphism)
fricas
eq3_6:= X' = sinh(r[1])/r[1]*X
Type: Equation(Expression(Integer))
fricas
eq3_7:= γ = cosh(r[1])
Type: Equation(Expression(Integer))
fricas
eq3_8:= exp(X) = 1+X'+X'^2/(1+γ)
Type: Equation(Expression(Integer))
fricas
test(normalize(rhs eval(eq3_8,[eq3_6,eq3_7]) - rhs eq3_4)=0)
Type: Boolean
Exercise 4.3
fricas
eval(eq3_1,[r[3]=r[2]])
Type: Equation(Polynomial(Integer))
fricas
eq3_9a:=lhs eq3_3a = limit(rhs eq3_3a,r[3]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
(numer rhs eq3_9a)/factor(denom rhs eq3_9a)
Type: SparseMultivariatePolynomial
?(Fraction(Factored(SparseMultivariatePolynomial
?(Integer,
Kernel(Expression(Integer))))),
Kernel(Expression(Integer)))
fricas
eq3_9b:=lhs eq3_3b = limit(rhs eq3_3b,r[3]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
(numer rhs eq3_9b)/factor(denom rhs eq3_9b)
Type: SparseMultivariatePolynomial
?(Fraction(Factored(SparseMultivariatePolynomial
?(Integer,
Kernel(Expression(Integer))))),
Kernel(Expression(Integer)))
fricas
eq3_9c:=lhs eq3_3c = limit(rhs eq3_3c,r[3]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
(numer rhs eq3_9c)/factor(denom rhs eq3_9c)
Type: SparseMultivariatePolynomial
?(Fraction(Factored(SparseMultivariatePolynomial
?(Integer,
Kernel(Expression(Integer))))),
Kernel(Expression(Integer)))
- Polynomial of degree 4
fricas
n:=4
fricas
eq4_1:= m[X]=(x-r[1])*(x-r[2])*(x-r[3])*(x-r[4])
Type: Equation(Polynomial(Integer))
fricas
eq4_2:= g[0]=groupPolyCoeff(0)
Type: Equation(Expression(Integer))
fricas
eq4_3:= g[1]=groupPolyCoeff(1)
Type: Equation(Expression(Integer))
fricas
eq4_4:= g[2]=groupPolyCoeff(2)
Type: Equation(Expression(Integer))
fricas
eq4_5:= g[3]=groupPolyCoeff(3)
Type: Equation(Expression(Integer))
-
fricas
eq5_1:=eval(eq4_1,[r[3]=-r[1],r[4]=-r[2]])
Type: Equation(Polynomial(Integer))
Corollary 6.1
fricas
eq5_2:= exp(X)=g[0]+g[1]*X+g[2]*X^2+g[3]*X^3
Type: Equation(Expression(Integer))
fricas
eq5_3a:= eval(eq4_2,[r[3]=-r[1],r[4]=-r[2]])
Type: Equation(Expression(Integer))
fricas
htrigs rhs %
Type: Expression(Integer)
fricas
eq5_3b:= eval(eq4_3,[r[3]=-r[1],r[4]=-r[2]])
Type: Equation(Expression(Integer))
fricas
htrigs rhs %
Type: Expression(Integer)
fricas
eq5_3c:= eval(eq4_4,[r[3]=-r[1],r[4]=-r[2]])
Type: Equation(Expression(Integer))
fricas
htrigs rhs %
Type: Expression(Integer)
fricas
eq5_3d:= eval(eq4_5,[r[3]=-r[1],r[4]=-r[2]])
Type: Equation(Expression(Integer))
fricas
htrigs rhs %
Type: Expression(Integer)
fricas
eq5_4:= eval(eval(eq5_2,[eq4_2,eq4_3,eq4_4,eq4_5]),[r[3]=-r[1],r[4]=-r[2]])
Type: Equation(Expression(Integer))
fricas
htrigs rhs %
Type: Expression(Integer)
Definition 6.2
fricas
eq5_5a:= Y[1] = 1/(2*r[1]^2-r[1]^2-r[2]^2)*(X^3-(r[1]^2+r[2]^2-r[1]^2)*X)
Type: Equation(Fraction(Polynomial(Integer)))
fricas
eq5_5b:= Y[2] = 1/(2*r[2]^2-r[1]^2-r[2]^2)*(X^3-(r[1]^2+r[2]^2-r[2]^2)*X)
Type: Equation(Fraction(Polynomial(Integer)))
Exercise 6.3
fricas
eq5_6a:= X = Y[1]+Y[2]
Type: Equation(Polynomial(Integer))
fricas
test(eval(eq5_6a,[eq5_5a,eq5_5b]))
Type: Boolean
fricas
eq5_6b:= eval(Y[1]*Y[2]=0,[eq5_5a,eq5_5b])
Type: Equation(Expression(Integer))
fricas
eq5_6c:= X^4 = X^4-eval(rhs eq5_1,x=X)
Type: Equation(Polynomial(Integer))
fricas
eq5_6d:= X^2*(lhs %)=X^2*(rhs %)
Type: Equation(Polynomial(Integer))
fricas
test(_rule(lhs eq5_6d,rhs eq5_6d)(lhs eq5_6b)=rhs eq5_6b)
Type: Boolean
Comment 6.5 (Rescaling)
fricas
eq5_7:= sinh(r[1])/r[1]*Y[1]+sinh(r[2])/r[2]*Y[2]
Type: Expression(Integer)
fricas
eq5_8a:= [ Y'[1]=sinh(r[1])/r[1]*Y[1], Y'[2]=sinh(r[2])/r[2]*Y[2] ]
Type: List(Equation(Expression(Integer)))
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eq5_8b:= [ γ[1] = cosh(r[1]), γ[2] = cosh(r[2]) ]
Type: List(Equation(Expression(Integer)))
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eq5_9a:= exp(X) = exp(Y[1])*exp(Y[2])
Type: Equation(Expression(Integer))
fricas
eval(eq5_9a,[eq5_5a,eq5_5b])
Type: Equation(Expression(Integer))
fricas
test(lhs % = simplify expand rhs %)
Type: Boolean
fricas
eq5_9b:= exp(X) = 1 + Y'[1] +Y'[2] + Y'[1]^2/(1+γ[1]) + Y'[2]^2/(1+γ[2])
Type: Equation(Expression(Integer))
fricas
normalize eval(eval(rhs eq5_9b,concat [eq5_8a,eq5_8b]),[eq5_5a,eq5_5b])
Type: Expression(Integer)
fricas
_rule(lhs eq5_6d,rhs eq5_6d)(%)
Type: Expression(Integer)
fricas
_rule(lhs eq5_6c,rhs eq5_6c)(%)
Type: Expression(Integer)
fricas
test(normalize(% - rhs eq5_4) = 0)
Type: Boolean
- Multiple roots for polynomial of degree four
Exercise 7.1
fricas
eval(eq4_1,r[4]=r[3])
Type: Equation(Polynomial(Integer))
fricas
eq6_1a:=lhs eq4_2 = limit(rhs eq4_2,r[4]=r[3])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
collect(rhs(eq6_1a), exp(r[1]))::OutputForm+collect(rhs(eq6_1a), exp(r[2]))::OutputForm+ _
sum _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_1a), exp(r[3])),(r[3]-r[1])::Expression Integer)]
fricas
Compiling function collect with type (OrderedCompletion(Expression(
Integer)),Expression(Integer)) -> Fraction(Factored(
SparseMultivariatePolynomial(Integer,Kernel(Expression(Integer)))
))
fricas
Compiling function sum with type List(OutputForm) -> OutputForm
fricas
eq6_1b:=lhs eq4_3 = limit(rhs eq4_3,r[4]=r[3])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
collect(rhs(eq6_1b), exp(r[1]))::OutputForm+collect(rhs(eq6_1b), exp(r[2]))::OutputForm+ _
sum _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_1b), exp(r[3])),(r[3]-r[1])::Expression Integer)]
fricas
eq6_1c:=lhs eq4_4 = limit(rhs eq4_4,r[4]=r[3])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
collect(rhs(eq6_1c), exp(r[1]))::OutputForm+collect(rhs(eq6_1c), exp(r[2]))::OutputForm+ _
sum _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_1c), exp(r[3])),(r[3]-r[1])::Expression Integer)]
fricas
eq6_1d:=lhs eq4_5 = limit(rhs eq4_5,r[4]=r[3])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
collect(rhs(eq6_1d), exp(r[1]))::OutputForm+collect(rhs(eq6_1d), exp(r[2]))::OutputForm+ _
sum _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_1d), exp(r[3])),(r[3]-r[1])::Expression Integer)]
Exercise 7.3 (Double root)
fricas
eval(eq4_1,[r[3]=r[1],r[4]=r[2]])
Type: Equation(Polynomial(Integer))
fricas
eq6_3a:=lhs eq4_2 = limit(limit(rhs eq4_2,r[3]=r[1]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat( _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3a), exp(r[1])),(r[2]-r[1])::Expression Integer)] , _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3a), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
fricas
eq6_3b:=lhs eq4_3 = limit(limit(rhs eq4_3,r[3]=r[1]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat( _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3b), exp(r[1])),(r[2]-r[1])::Expression Integer)] , _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3b), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
fricas
eq6_3c:=lhs eq4_4 = limit(limit(rhs eq4_4,r[3]=r[1]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat( _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3c), exp(r[1])),(r[2]-r[1])::Expression Integer)] , _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3c), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
fricas
eq6_3d:=lhs eq4_5 = limit(limit(rhs eq4_5,r[3]=r[1]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat( _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3d), exp(r[1])),(r[2]-r[1])::Expression Integer)] , _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_3d), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
Exercise 7.4 (Triple root)
fricas
eval(eq4_1,[r[3]=r[2],r[4]=r[2]])
Type: Equation(Polynomial(Integer))
fricas
eq6_4a:=lhs eq4_2 = limit(limit(rhs eq4_2,r[3]=r[2]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat(collect(rhs(eq6_4a), exp(r[1]))::OutputForm, _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_4a), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
fricas
eq6_4b:=lhs eq4_3 = limit(limit(rhs eq4_3,r[3]=r[2]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat(collect(rhs(eq6_4b), exp(r[1]))::OutputForm, _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_4b), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
fricas
eq6_4c:=lhs eq4_4 = limit(limit(rhs eq4_4,r[3]=r[2]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat(collect(rhs(eq6_4c), exp(r[1]))::OutputForm, _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_4c), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
fricas
eq6_4d:=lhs eq4_5 = limit(limit(rhs eq4_5,r[3]=r[2]),r[4]=r[2])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
sum concat(collect(rhs(eq6_4d), exp(r[1]))::OutputForm, _
[((factor numer x)/(factor denom x))::OutputForm _
for x in collector(collect(rhs(eq6_4d), exp(r[2])),(r[2]-r[1])::Expression Integer)] )
- Parabolic isometries: single many-fold root
Exercise 8.1 (Degree two)
fricas
eval(eq2_2,[r[2]=r[1]])
Type: Equation(Expression(Integer))
fricas
lhs eq2_3a = limit(rhs eq2_3a,r[2]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
lhs eq2_3b = limit(rhs eq2_3b,r[2]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
Exercise 8.2 (Triple root)
fricas
eval(eq3_1,[r[2]=r[1],r[3]=r[1]])
Type: Equation(Polynomial(Integer))
fricas
lhs eq3_3a = limit(limit(rhs eq3_3a,r[2]=r[1]),r[3]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
lhs eq3_3b = limit(limit(rhs eq3_3b,r[2]=r[1]),r[3]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
lhs eq3_3c = limit(limit(rhs eq3_3c,r[2]=r[1]),r[3]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
Exercise 8.3 (Fourfold root)
fricas
eval(eq4_1,[r[2]=r[1],r[3]=r[1],r[4]=r[1]])
Type: Equation(Polynomial(Integer))
fricas
lhs eq4_2 = limit(limit(limit(rhs eq4_2,r[2]=r[1]),r[3]=r[1]),r[4]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
lhs eq4_3 = limit(limit(limit(rhs eq4_3,r[2]=r[1]),r[3]=r[1]),r[4]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
lhs eq4_4 = limit(limit(limit(rhs eq4_4,r[2]=r[1]),r[3]=r[1]),r[4]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))
fricas
lhs eq4_5 = limit(limit(limit(rhs eq4_5,r[2]=r[1]),r[3]=r[1]),r[4]=r[1])
Type: Equation(OrderedCompletion
?(Expression(Integer)))