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Edit detail for SandBoxHermitianIsomorphisms revision 6 of 7

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Editor: Bill Page
Time: 2011/06/26 16:09:30 GMT-7
Note: documentation

added:
A complex vector ℂ-space $V$ possesses many different hermitian isomorphisms
$h^\dagger=h \in iso(V,V^\dagger)$. In quantum mechanics a given operator
$\rho \in End(V)$ may be said to be $h$-hermitian if
$$
\rho^\dagger \circ h = h \circ \rho
$$

changed:
-p:Complex Fraction Polynomial Integer:=complex(ℜp,𝔍p)
-q:Complex Fraction Polynomial Integer:=complex(ℜq,𝔍q)
-r:Complex Fraction Polynomial Integer:=complex(ℜr,𝔍r)
-t:Complex Fraction Polynomial Integer:=complex(ℜt,0)
-ρ:=matrix [[t/2+p,q],[r,t/2-p]]
ℂ:=Complex Fraction Polynomial Integer
-- dagger
htranspose(h)==map(x+->conjugate(x),transpose h)
)expose MCALCFN
\end{axiom}

Theorem

  The necessary conditions for an operator $ρ$ to possess hermitean isomorphism
$h$ is that $trace ρ \in ℝ$ and $det ρ \in ℝ$.

Two-Dimensions

\begin{axiom}
p:ℂ:=complex(ℜp,𝔍p)
q:ℂ:=complex(ℜq,𝔍q)
r:ℂ:=complex(ℜr,𝔍r)
t:ℂ:=complex(ℜt,0)
ρ:Matrix ℂ := matrix [[t/2+p,q],[r,t/2-p]]

added:
test(p^2+r*q=(1/4)*t^2-d)

removed:
-test(p^2+r*q=(1/4)*t^2-d)

added:

Given an operator $ρ \in End V$, one must find the tensor $H=0$
for unknown manifold of hermitian isomorphisms $h$.

changed:
-h:Matrix Complex Polynomial Integer:=matrix [[a,complex(b,c)],[complex(b,-c),e]]
-htranspose(h)==map(x+->conjugate(x),transpose h)
h:Matrix ℂ:=matrix [[a,complex(b,c)],[complex(b,-c),e]]

added:
H:=htranspose(ρ)*h-h*ρ

added:

We wish to find expressions for $h$ in terms of the components of
$ρ$. To do this we will determine how the components of $H$ depend
on the components of $h$.

changed:
-H:=htranspose(ρ)*h-h*ρ
-Hlist:=concat(H::List List ?)
-Hreal:=removeDuplicates(select(x+->(x~=0),concat(map(x+->real x, Hlist),map(x+->imag x, Hlist))))
-)expose MCALCFN
-H1:=jacobian(Hreal,[a,b,c,e]::List Symbol)
J:=jacobian(concat( map(x+->[real x, imag x], concat(H::List List ?)) ),
     [a,b,c,e]::List Symbol)

added:
The null space (kernel) of the Jacobian

changed:
-s1:=solve(determinant subMatrix(H1,2,5,1,4),ℜr)
-H2:=map(x+->eval(x,s1),H1)
-N:=nullSpace(H2)
-H2*(c*N(1)+e*N(2))
-s2:=map((x,y)+->x=y,[a,b,c,e],c*N.1+e*N.2)
-h1:=map(x+->eval(x,s2),h)
-map(x+->eval(x,s1),htranspose(ρ)*h1-h1*ρ)
N:=nullSpace(map(x+->eval(x,s0),J))

added:
gives the general solution to the problem.
\begin{axiom}
s1:=map((x,y)+->x=y,[a,b,c,e],c*N.1+e*N.2)
map(x+->eval(x,concat(s0,s1)),H)
\end{axiom}

A complex vector ℂ-space V possesses many different hermitian isomorphisms h^\dagger=h \in iso(V,V^\dagger). In quantum mechanics a given operator \rho \in End(V) may be said to be h-hermitian if


\rho^\dagger \circ h = h \circ \rho
 
axiom
ℂ:=Complex Fraction Polynomial Integer

\label{eq1}\hbox{\axiomType{Complex}\ } (\hbox{\axiomType{Fraction}\ } (\hbox{\axiomType{Polynomial}\ } (\hbox{\axiomType{Integer}\ })))(1)
Type: Type
axiom
-- dagger
htranspose(h)==map(x+->conjugate(x),transpose h)
Type: Void
axiom
)expose MCALCFN
MultiVariableCalculusFunctions is now explicitly exposed in frame initial

Theorem

The necessary conditions for an operator ρ to possess hermitean isomorphism h is that trace ρ \in ℝ and det ρ \in ℝ.

Two-Dimensions

axiom
p:ℂ:=complex(ℜp,𝔍p)

\label{eq2}� � p +{�� � p \  i}(2)
Type: Complex(Fraction(Polynomial(Integer)))
axiom
q:ℂ:=complex(ℜq,𝔍q)

\label{eq3}� � q +{�� � q \  i}(3)
Type: Complex(Fraction(Polynomial(Integer)))
axiom
r:ℂ:=complex(ℜr,𝔍r)

\label{eq4}� � r +{�� � r \  i}(4)
Type: Complex(Fraction(Polynomial(Integer)))
axiom
t:ℂ:=complex(ℜt,0)

\label{eq5}� � t(5)
Type: Complex(Fraction(Polynomial(Integer)))
axiom
ρ:Matrix ℂ := matrix [[t/2+p,q],[r,t/2-p]]

\label{eq6}\left[ 
\begin{array}{cc}
{{{� � t +{2 \  � � p}}\over 2}+{�� � p \  i}}&{� � q +{�� � q \  i}}
\
{� � r +{�� � r \  i}}&{{{� � t -{2 \  � � p}}\over 2}-{�� � p \  i}}
(6)
Type: Matrix(Complex(Fraction(Polynomial(Integer))))
axiom
trace ρ

\label{eq7}� � t(7)
Type: Complex(Fraction(Polynomial(Integer)))
axiom
d:=determinant ρ

\label{eq8}{{{4 \  �� � q \  �� � r}+{4 \ {�� � p^2}}+{� � t^2}-{4 \  � � q \  � � r}-{4 \ {� � p^2}}}\over 4}+{{\left(-{� � q \  �� � r}-{� � r \  �� � q}-{2 \  � � p \  �� � p}\right)}\  i}(8)
Type: Complex(Fraction(Polynomial(Integer)))
axiom
test(p^2+r*q=(1/4)*t^2-d)

\label{eq9} \mbox{\rm true} (9)
Type: Boolean
axiom
s0:=solve(imag d,ℜr)

\label{eq10}\left[{� � r ={{-{� � q \  �� � r}-{2 \  � � p \  �� � p}}\over �� � q}}\right](10)
Type: List(Equation(Fraction(Polynomial(Integer))))
axiom
eval(trace(ρ*ρ),s0)

\label{eq11}{{{\left(-{4 \ {�� � q^2}}-{4 \ {� � q^2}}\right)}\  �� � r}+{{\left(-{4 \ {�� � p^2}}+{� � t^2}+{4 \ {� � p^2}}\right)}\  �� � q}-{8 \  � � p \  � � q \  �� � p}}\over{2 \  �� � q}(11)
Type: Fraction(Polynomial(Complex(Integer)))

Given an operator ρ \in End V, one must find the tensor H=0 for unknown manifold of hermitian isomorphisms h.

axiom
h:Matrix ℂ:=matrix [[a,complex(b,c)],[complex(b,-c),e]]

\label{eq12}\left[ 
\begin{array}{cc}
a &{b +{c \  i}}
\
{b -{c \  i}}& e 
(12)
Type: Matrix(Complex(Fraction(Polynomial(Integer))))
axiom
test(h = htranspose h)
axiom
Compiling function htranspose with type Matrix(Complex(Fraction(
      Polynomial(Integer)))) -> Matrix(Complex(Fraction(Polynomial(
      Integer))))

\label{eq13} \mbox{\rm true} (13)
Type: Boolean
axiom
H:=htranspose(ρ)*h-h*ρ

\label{eq14}\left[ 
\begin{array}{cc}
{{\left(-{2 \  b \  �� � r}-{2 \  a \  �� � p}-{2 \  c \  � � r}\right)}\  i}&{{e \  � � r}-{a \  � � q}+{2 \  b \  � � p}+{{\left(-{e \  �� � r}-{a \  �� � q}+{2 \  c \  � � p}\right)}\  i}}
\
{-{e \  � � r}+{a \  � � q}-{2 \  b \  � � p}+{{\left(-{e \  �� � r}-{a \  �� � q}+{2 \  c \  � � p}\right)}\  i}}&{{\left(-{2 \  b \  �� � q}+{2 \  e \  �� � p}+{2 \  c \  � � q}\right)}\  i}
(14)
Type: Matrix(Complex(Fraction(Polynomial(Integer))))

We wish to find expressions for h in terms of the components of ρ. To do this we will determine how the components of H depend on the components of h.

axiom
J:=jacobian(concat( map(x+->[real x, imag x], concat(H::List List ?)) ),
     [a,b,c,e]::List Symbol)

\label{eq15}\left[ 
\begin{array}{cccc}
0 & 0 & 0 & 0 
\
-{2 \  �� � p}& -{2 \  �� � r}& -{2 \  � � r}& 0 
\
- � � q &{2 \  � � p}& 0 & � � r 
\
- �� � q & 0 &{2 \  � � p}& - �� � r 
\
� � q & -{2 \  � � p}& 0 & - � � r 
\
- �� � q & 0 &{2 \  � � p}& - �� � r 
\
0 & 0 & 0 & 0 
\
0 & -{2 \  �� � q}&{2 \  � � q}&{2 \  �� � p}
(15)
Type: Matrix(Fraction(Polynomial(Integer)))

The null space (kernel) of the Jacobian

axiom
N:=nullSpace(map(x+->eval(x,s0),J))

\label{eq16}\left[{\left[{{2 \  � � p}\over �� � q}, \:{� � q \over �� � q}, \: 1, \: 0 \right]}, \:{\left[ -{�� � r \over �� � q}, \:{�� � p \over �� � q}, \: 0, \: 1 \right]}\right](16)
Type: List(Vector(Fraction(Polynomial(Integer))))

gives the general solution to the problem.

axiom
s1:=map((x,y)+->x=y,[a,b,c,e],c*N.1+e*N.2)

\label{eq17}\left[{a ={{-{e \  �� � r}+{2 \  c \  � � p}}\over �� � q}}, \:{b ={{{e \  �� � p}+{c \  � � q}}\over �� � q}}, \:{c = c}, \:{e = e}\right](17)
Type: List(Equation(Fraction(Polynomial(Integer))))
axiom
map(x+->eval(x,concat(s0,s1)),H)

\label{eq18}\left[ 
\begin{array}{cc}
0 & 0 
\
0 & 0 
(18)
Type: Matrix(Fraction(Polynomial(Complex(Integer))))