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SandBox Idempotent Observers

last edited 7 years ago by Bill Page

Edit detail for SandBox Idempotent Observers revision 10 of 29

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Editor: Bill Page Time: 2013/10/14 05:59:43 GMT+0
Note: Momentum

changed:
-ω(P,Q)
-ω(S,T)
map(Simplify, ω(P,Q))
map(Simplify, ω(P,R))
map(Simplify, ω(S,T))
map(Simplify, ω(S,R))

changed:
-1/trace(%)*%
map(x+->(sqrt(p1^2+p2^2+p3^2+1)*numer(x))/(sqrt(p1^2+p2^2+p3^2+1)*denom(x)),1/trace(%)*%)
trace %

changed:
---1/trace(%)*%
--map(Simplify,1/trace(%)*%)

Mathematical Preliminaries

Space-time without reference frames

A vector is represented as a $n\times 1$ matrix (column vector)

fricas

Scalar := Expression Integer

$\label{eq1}\hbox{\axiomType{Expression}\ } (\hbox{\axiomType{Integer}\ })$

(1)

Type: Type

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vect(x:List Scalar):Matrix Scalar == matrix map(y+->[y],x)

   Function declaration vect : List(Expression(Integer)) -> Matrix(
      Expression(Integer)) has been added to workspace.

Type: Void

fricas

vect [a0,a1,a2,a3]

fricas

Compiling function vect with type List(Expression(Integer)) -> 
      Matrix(Expression(Integer))

$\label{eq2}\left[ \begin{array}{c} a 0 \ a 1 \ a 2 \ a 3$

(2)

Type: Matrix(Expression(Integer))

Identity

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ID:=diagonalMatrix([1,1,1,1])

$\label{eq3}\left[ \begin{array}{cccc} 1 & 0 & 0 & 0 \ 0 & 1 & 0 & 0 \ 0 & 0 & 1 & 0 \ 0 & 0 & 0 & 1$

(3)

Type: Matrix(Integer)

Verification

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htrigs2exp == rule
  cosh(a) == (exp(a)+exp(-a))/2
  sinh(a) == (exp(a)-exp(-a))/2

Type: Void

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sinhcosh == rule
  ?c*exp(a)+?c*exp(-a) == 2*c*cosh(a)
  ?c*exp(a)-?c*exp(-a) == 2*c*sinh(a)
  ?c*exp(a-b)+?c*exp(b-a) == 2*c*cosh(a-b)
  ?c*exp(a-b)-?c*exp(b-a) == 2*c*sinh(a-b)

Type: Void

fricas

expandhtrigs == rule
  cosh(:x+y) == sinh(x)*sinh(y)+cosh(x)*cosh(y)
  sinh(:x+y) == cosh(x)*sinh(y)+sinh(x)*cosh(y)
  cosh(2*x) == 2*cosh(x)^2-1
  sinh(2*x) == 2*sinh(x)*cosh(x)

Type: Void

fricas

expandhtrigs2 == rule
  cosh(2*x+2*y) == 2*cosh(x+y)^2-1
  sinh(2*x+2*y) == 2*sinh(x+y)*cosh(x+y)
  cosh(2*x-2*y) == 2*cosh(x-y)^2-1
  sinh(2*x-2*y) == 2*sinh(x-y)*cosh(x-y)

Type: Void

fricas

Simplify(x:Scalar):Scalar == htrigs sinhcosh simplify htrigs2exp x

   Function declaration Simplify : Expression(Integer) -> Expression(
      Integer) has been added to workspace.

Type: Void

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possible(x)==subst(x, map(y+->(y=(random(100) - random(100))),variables x) )

Type: Void

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is?(eq:Equation Scalar):Boolean == (Simplify(lhs(eq)-rhs(eq))=0)::Boolean

   Function declaration is? : Equation(Expression(Integer)) -> Boolean 
      has been added to workspace.

Type: Void

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Is?(eq:Equation(Matrix(Scalar))):Boolean == _
(map(Simplify,lhs(eq)-rhs(eq)) :: Matrix Expression AlgebraicNumber = _
zero(nrows(lhs(eq)),ncols(lhs(eq)))$Matrix Expression AlgebraicNumber )::Boolean

   Function declaration Is? : Equation(Matrix(Expression(Integer))) -> 
      Boolean has been added to workspace.

Type: Void

Lorentz Form (metric)

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G:=diagonalMatrix [-1,1,1,1]

$\label{eq4}\left[ \begin{array}{cccc} - 1 & 0 & 0 & 0 \ 0 & 1 & 0 & 0 \ 0 & 0 & 1 & 0 \ 0 & 0 & 0 & 1$

(4)

Type: Matrix(Integer)

applied to a vector produces a co-vector (represent as a $1\times n$ matrix or row vector)

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g(x) == transpose(x)*G

Type: Void

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g(vect [a0,a1,a2,a3])

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Compiling function g with type Matrix(Expression(Integer)) -> Matrix
      (Expression(Integer))

$\label{eq5}\left[ \begin{array}{cccc} - a 0 & a 1 & a 2 & a 3$

(5)

Type: Matrix(Expression(Integer))

Scalar product

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dot(x,y) == (g(x)*y)::Scalar

Type: Void

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dot(vect [a0,a1,a2,a3], vect [b0,b1,b2,b3])

fricas

Compiling function dot with type (Matrix(Expression(Integer)),Matrix
      (Expression(Integer))) -> Expression(Integer)

$\label{eq6}{a 3 \ b 3}+{a 2 \ b 2}+{a 1 \ b 1}-{a 0 \ b 0}$

(6)

Type: Expression(Integer)

Tensor product

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tensor(x,y) == x*g(y)

Type: Void

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tensor(vect [a0,a1,a2,a3], vect [b0,b1,b2,b3])

fricas

Compiling function tensor with type (Matrix(Expression(Integer)),
      Matrix(Expression(Integer))) -> Matrix(Expression(Integer))

$\label{eq7}\left[ \begin{array}{cccc} -{a 0 \ b 0}&{a 0 \ b 1}&{a 0 \ b 2}&{a 0 \ b 3} \ -{a 1 \ b 0}&{a 1 \ b 1}&{a 1 \ b 2}&{a 1 \ b 3} \ -{a 2 \ b 0}&{a 2 \ b 1}&{a 2 \ b 2}&{a 2 \ b 3} \ -{a 3 \ b 0}&{a 3 \ b 1}&{a 3 \ b 2}&{a 3 \ b 3}$

(7)

Type: Matrix(Expression(Integer))

Massive Objects

A material object (also referred to as an observer) is represented by a time-like 4-vector

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P:=vect [sqrt(p1^2+p2^2+p3^2+1),-p1,-p2,-p3];

Type: Matrix(Expression(Integer))

fricas

dot(P,P)

$\label{eq8}- 1$

(8)

Type: Expression(Integer)

fricas

Q:=vect [sqrt(q1^2+q2^2+q3^2+1),-q1,-q2,-q3];

Type: Matrix(Expression(Integer))

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S:=1/sqrt(1-s1^2-s2^2-s3^2)*vect [1,-s1,-s2,-s3]

$\label{eq9}\left[ \begin{array}{c} {1 \over{\sqrt{-{{s 3}^{2}}-{{s 2}^{2}}-{{s 1}^{2}}+ 1}}} \ -{s 1 \over{\sqrt{-{{s 3}^{2}}-{{s 2}^{2}}-{{s 1}^{2}}+ 1}}} \ -{s 2 \over{\sqrt{-{{s 3}^{2}}-{{s 2}^{2}}-{{s 1}^{2}}+ 1}}} \ -{s 3 \over{\sqrt{-{{s 3}^{2}}-{{s 2}^{2}}-{{s 1}^{2}}+ 1}}}$

(9)

Type: Matrix(Expression(Integer))

fricas

dot(S,S)

$\label{eq10}- 1$

(10)

Type: Expression(Integer)

fricas

T:=1/sqrt(1-t1^2-t2^2-t3^2)*vect [1,-t1,-t2,-t3]

$\label{eq11}\left[ \begin{array}{c} {1 \over{\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}} \ -{t 1 \over{\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}} \ -{t 2 \over{\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}} \ -{t 3 \over{\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}}$

(11)

Type: Matrix(Expression(Integer))

fricas

U:=vect [cosh(u),sinh(u),0,0]

$\label{eq12}\left[ \begin{array}{c} {\cosh \left({u}\right)} \ {\sinh \left({u}\right)} \ 0 \ 0$

(12)

Type: Matrix(Expression(Integer))

fricas

simplify dot(U,U)

$\label{eq13}- 1$

(13)

Type: Expression(Integer)

fricas

V:=vect [cosh(v),sinh(v),0,0]

$\label{eq14}\left[ \begin{array}{c} {\cosh \left({v}\right)} \ {\sinh \left({v}\right)} \ 0 \ 0$

(14)

Type: Matrix(Expression(Integer))

fricas

Simplify dot(U,V)

fricas

Compiling body of rule htrigs2exp to compute value of type Ruleset(
      Integer,Integer,Expression(Integer))

fricas

Compiling body of rule sinhcosh to compute value of type Ruleset(
      Integer,Integer,Expression(Integer))

fricas

Compiling function Simplify with type Expression(Integer) -> 
      Expression(Integer)

$\label{eq15}-{\cosh \left({v - u}\right)}$

(15)

Type: Expression(Integer)

fricas

W:=vect [cosh(w),0,sinh(w),0]

$\label{eq16}\left[ \begin{array}{c} {\cosh \left({w}\right)} \ 0 \ {\sinh \left({w}\right)} \ 0$

(16)

Type: Matrix(Expression(Integer))

fricas

Simplify dot(U,W)

$\label{eq17}{-{\cosh \left({w + u}\right)}-{\cosh \left({w - u}\right)}}\over 2$

(17)

Type: Expression(Integer)

Observer "at rest"

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R:=vect [1,0,0,0]

$\label{eq18}\left[ \begin{array}{c} 1 \ 0 \ 0 \ 0$

(18)

Type: Matrix(Expression(Integer))

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dot(R,R)

$\label{eq19}- 1$

(19)

Type: Expression(Integer)

Associated with each such vector is the orthogonal 3-d Euclidean subspace $E_P =\{x | P \cdot x = 0\}$

Relative Velocity

An object P has a unique relative velocity ω(P,Q) with respect to object Q given by

fricas

ω(P,Q)==-P/dot(P,Q)-Q

Type: Void

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map(Simplify, ω(P,Q))

fricas

Compiling function ω with type (Matrix(Expression(Integer)),Matrix(
      Expression(Integer))) -> Matrix(Expression(Integer))

$\label{eq20}\left[ \begin{array}{c} {{{{\left({p 3 \ q 3}+{p 2 \ q 2}+{p 1 \ q 1}\right)}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}+{{\left(-{{q 3}^{2}}-{{q 2}^{2}}-{{q 1}^{2}}\right)}\ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}}\over{{{\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}-{p 3 \ q 3}-{p 2 \ q 2}-{p 1 \ q 1}}} \ {{{q 1 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}-{p 3 \ q 1 \ q 3}-{p 2 \ q 1 \ q 2}-{p 1 \ {{q 1}^{2}}}- p 1}\over{{{\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}-{p 3 \ q 3}-{p 2 \ q 2}-{p 1 \ q 1}}} \ {{{q 2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}-{p 3 \ q 2 \ q 3}-{p 2 \ {{q 2}^{2}}}-{p 1 \ q 1 \ q 2}- p 2}\over{{{\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}-{p 3 \ q 3}-{p 2 \ q 2}-{p 1 \ q 1}}} \ {{{q 3 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}-{p 3 \ {{q 3}^{2}}}+{{\left(-{p 2 \ q 2}-{p 1 \ q 1}\right)}\ q 3}- p 3}\over{{{\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}\ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}-{p 3 \ q 3}-{p 2 \ q 2}-{p 1 \ q 1}}}$

(20)

Type: Matrix(Expression(Integer))

fricas

map(Simplify, ω(P,R))

$\label{eq21}\left[ \begin{array}{c} 0 \ -{p 1 \over{\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}} \ -{p 2 \over{\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}} \ -{p 3 \over{\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}$

(21)

Type: Matrix(Expression(Integer))

fricas

map(Simplify, ω(S,T))

$\label{eq22}\left[ \begin{array}{c} {{{{t 3}^{2}}-{s 3 \ t 3}+{{t 2}^{2}}-{s 2 \ t 2}+{{t 1}^{2}}-{s 1 \ t 1}}\over{{\left({s 3 \ t 3}+{s 2 \ t 2}+{s 1 \ t 1}- 1 \right)}\ {\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}}} \ {{-{s 1 \ {{t 3}^{2}}}+{s 3 \ t 1 \ t 3}-{s 1 \ {{t 2}^{2}}}+{s 2 \ t 1 \ t 2}- t 1 + s 1}\over{{\left({s 3 \ t 3}+{s 2 \ t 2}+{s 1 \ t 1}- 1 \right)}\ {\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}}} \ {{-{s 2 \ {{t 3}^{2}}}+{s 3 \ t 2 \ t 3}+{{\left({s 1 \ t 1}- 1 \right)}\ t 2}-{s 2 \ {{t 1}^{2}}}+ s 2}\over{{\left({s 3 \ t 3}+{s 2 \ t 2}+{s 1 \ t 1}- 1 \right)}\ {\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}}} \ {{{{\left({s 2 \ t 2}+{s 1 \ t 1}- 1 \right)}\ t 3}-{s 3 \ {{t 2}^{2}}}-{s 3 \ {{t 1}^{2}}}+ s 3}\over{{\left({s 3 \ t 3}+{s 2 \ t 2}+{s 1 \ t 1}- 1 \right)}\ {\sqrt{-{{t 3}^{2}}-{{t 2}^{2}}-{{t 1}^{2}}+ 1}}}}$

(22)

Type: Matrix(Expression(Integer))

fricas

map(Simplify, ω(S,R))

$\label{eq23}\left[ \begin{array}{c} 0 \ - s 1 \ - s 2 \ - s 3$

(23)

Type: Matrix(Expression(Integer))

fricas

map(Simplify, ω(U,V))

$\label{eq24}\left[ \begin{array}{c} {{-{\cosh \left({{2 \ v}- u}\right)}+{\cosh \left({u}\right)}}\over{2 \ {\cosh \left({v - u}\right)}}} \ {{-{\sinh \left({{2 \ v}- u}\right)}+{\sinh \left({u}\right)}}\over{2 \ {\cosh \left({v - u}\right)}}} \ 0 \ 0$

(24)

Type: Matrix(Expression(Integer))

Idempotent Observers

fricas

PP:=tensor(-P,P)

$\label{eq25}\left[ \begin{array}{cccc} {{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}&{p 1 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}&{p 2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}&{p 3 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}} \ -{p 1 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}& -{{p 1}^{2}}& -{p 1 \ p 2}& -{p 1 \ p 3} \ -{p 2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}& -{p 1 \ p 2}& -{{p 2}^{2}}& -{p 2 \ p 3} \ -{p 3 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}& -{p 1 \ p 3}& -{p 2 \ p 3}& -{{p 3}^{2}}$

(25)

Type: Matrix(Expression(Integer))

fricas

Is?(PP*PP=PP)

fricas

Compiling function Is? with type Equation(Matrix(Expression(Integer)
      )) -> Boolean

$\label{eq26} \mbox{\rm true}$

(26)

Type: Boolean

fricas

trace(PP)

$\label{eq27}1$

(27)

Type: Expression(Integer)

fricas

QQ:=tensor(-Q,Q)

$\label{eq28}\left[ \begin{array}{cccc} {{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}&{q 1 \ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}&{q 2 \ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}&{q 3 \ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}} \ -{q 1 \ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}& -{{q 1}^{2}}& -{q 1 \ q 2}& -{q 1 \ q 3} \ -{q 2 \ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}& -{q 1 \ q 2}& -{{q 2}^{2}}& -{q 2 \ q 3} \ -{q 3 \ {\sqrt{{{q 3}^{2}}+{{q 2}^{2}}+{{q 1}^{2}}+ 1}}}& -{q 1 \ q 3}& -{q 2 \ q 3}& -{{q 3}^{2}}$

(28)

Type: Matrix(Expression(Integer))

fricas

is?(trace(PP*QQ)=dot(P,Q)^2)

fricas

Compiling function is? with type Equation(Expression(Integer)) -> 
      Boolean

$\label{eq29} \mbox{\rm true}$

(29)

Type: Boolean

fricas

Is?(PP*QQ*PP = trace(PP*QQ)@Scalar * PP)

$\label{eq30} \mbox{\rm true}$

(30)

Type: Boolean

fricas

RR:=tensor(-R,R)

$\label{eq31}\left[ \begin{array}{cccc} 1 & 0 & 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0$

(31)

Type: Matrix(Expression(Integer))

fricas

SS:=map(Simplify,tensor(-S,S))

$\label{eq32}\left[ \begin{array}{cccc} -{1 \over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}& -{s 1 \over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}& -{s 2 \over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}& -{s 3 \over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}} \ {s 1 \over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{{s 1}^{2}}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{s 1 \ s 2}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{s 1 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}} \ {s 2 \over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{s 1 \ s 2}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{{s 2}^{2}}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{s 2 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}} \ {s 3 \over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{s 1 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{s 2 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}&{{{s 3}^{2}}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}- 1}}$

(32)

Type: Matrix(Expression(Integer))

fricas

TT:=map(Simplify,tensor(-T,T))

$\label{eq33}\left[ \begin{array}{cccc} -{1 \over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}& -{t 1 \over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}& -{t 2 \over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}& -{t 3 \over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}} \ {t 1 \over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{{t 1}^{2}}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{t 1 \ t 2}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{t 1 \ t 3}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}} \ {t 2 \over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{t 1 \ t 2}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{{t 2}^{2}}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{t 2 \ t 3}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}} \ {t 3 \over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{t 1 \ t 3}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{t 2 \ t 3}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}&{{{t 3}^{2}}\over{{{t 3}^{2}}+{{t 2}^{2}}+{{t 1}^{2}}- 1}}$

(33)

Type: Matrix(Expression(Integer))

fricas

UU:=map(Simplify,tensor(-U,U))

$\label{eq34}\left[ \begin{array}{cccc} {{{\cosh \left({2 \ u}\right)}+ 1}\over 2}& -{{\sinh \left({2 \ u}\right)}\over 2}& 0 & 0 \ {{\sinh \left({2 \ u}\right)}\over 2}&{{-{\cosh \left({2 \ u}\right)}+ 1}\over 2}& 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0$

(34)

Type: Matrix(Expression(Integer))

fricas

VV:=map(Simplify,tensor(-V,V))

$\label{eq35}\left[ \begin{array}{cccc} {{{\cosh \left({2 \ v}\right)}+ 1}\over 2}& -{{\sinh \left({2 \ v}\right)}\over 2}& 0 & 0 \ {{\sinh \left({2 \ v}\right)}\over 2}&{{-{\cosh \left({2 \ v}\right)}+ 1}\over 2}& 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0$

(35)

Type: Matrix(Expression(Integer))

fricas

map(Simplify, UU*VV)

$\label{eq36}\left[ \begin{array}{cccc} {{{\cosh \left({2 \ v}\right)}+{\cosh \left({{2 \ v}-{2 \ u}}\right)}+{\cosh \left({2 \ u}\right)}+ 1}\over 4}&{{-{\sinh \left({2 \ v}\right)}-{\sinh \left({{2 \ v}-{2 \ u}}\right)}-{\sinh \left({2 \ u}\right)}}\over 4}& 0 & 0 \ {{{\sinh \left({2 \ v}\right)}-{\sinh \left({{2 \ v}-{2 \ u}}\right)}+{\sinh \left({2 \ u}\right)}}\over 4}&{{-{\cosh \left({2 \ v}\right)}+{\cosh \left({{2 \ v}-{2 \ u}}\right)}-{\cosh \left({2 \ u}\right)}+ 1}\over 4}& 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0$

(36)

Type: Matrix(Expression(Integer))

Unit

fricas

n:=map(Simplify,PP*QQ+QQ*PP-PP-QQ);

Type: Matrix(Expression(Integer))

fricas

N:=map(Simplify,2/trace(n)*n);

Type: Matrix(Expression(Integer))

fricas

Simplify trace N

$\label{eq37}2$

(37)

Type: Expression(Integer)

fricas

Is?(N*N=N)

$\label{eq38} \mbox{\rm true}$

(38)

Type: Boolean

fricas

Is?(PP*N=PP)

$\label{eq39} \mbox{\rm true}$

(39)

Type: Boolean

fricas

Is?(QQ*N=QQ)

$\label{eq40} \mbox{\rm true}$

(40)

Type: Boolean

fricas

Is?(N*PP=PP)

$\label{eq41} \mbox{\rm true}$

(41)

Type: Boolean

fricas

Is?(N*QQ=QQ)

$\label{eq42} \mbox{\rm true}$

(42)

Type: Boolean

fricas

--SS*TT+TT*SS-SS-TT;
--2/trace(%)*%
PP*RR+RR*PP-PP-RR;

Type: Matrix(Expression(Integer))

fricas

2/trace(%)*%

$\label{eq43}\left[ \begin{array}{cccc} 1 & 0 & 0 & 0 \ 0 &{{{p 1}^{2}}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}}&{{p 1 \ p 2}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}}&{{p 1 \ p 3}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}} \ 0 &{{p 1 \ p 2}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}}&{{{p 2}^{2}}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}}&{{p 2 \ p 3}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}} \ 0 &{{p 1 \ p 3}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}}&{{p 2 \ p 3}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}}&{{{p 3}^{2}}\over{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}}}$

(43)

Type: Matrix(Expression(Integer))

fricas

SS*RR+RR*SS-SS-RR;

Type: Matrix(Expression(Integer))

fricas

2/trace(%)*%

$\label{eq44}\left[ \begin{array}{cccc} 1 & 0 & 0 & 0 \ 0 &{{{s 1}^{2}}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}}&{{s 1 \ s 2}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}}&{{s 1 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}} \ 0 &{{s 1 \ s 2}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}}&{{{s 2}^{2}}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}}&{{s 2 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}} \ 0 &{{s 1 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}}&{{s 2 \ s 3}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}}&{{{s 3}^{2}}\over{{{s 3}^{2}}+{{s 2}^{2}}+{{s 1}^{2}}}}$

(44)

Type: Matrix(Expression(Integer))

fricas

UU*RR+RR*UU-UU-RR;

Type: Matrix(Expression(Integer))

fricas

map(Simplify,2/trace(%)*%)

$\label{eq45}\left[ \begin{array}{cccc} 1 & 0 & 0 & 0 \ 0 & 1 & 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0$

(45)

Type: Matrix(Expression(Integer))

fricas

UU*VV+VV*UU-UU-VV;

Type: Matrix(Expression(Integer))

fricas

map(Simplify,2/trace(%)*%)

$\label{eq46}\left[ \begin{array}{cccc} 1 & 0 & 0 & 0 \ 0 & 1 & 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0$

(46)

Type: Matrix(Expression(Integer))

Momentum

fricas

m:=(PP*QQ+QQ*PP)/dot(P,Q)-PP-QQ;

Type: Matrix(Expression(Integer))

fricas

M:=1/trace(m)*m;

Type: Matrix(Expression(Integer))

fricas

trace M

$\label{eq47}1$

(47)

Type: Expression(Integer)

fricas

Is?(M*M=M)

$\label{eq48} \mbox{\rm true}$

(48)

Type: Boolean

fricas

(PP*RR+RR*PP)/dot(P,R)-PP-RR;

Type: Matrix(Expression(Integer))

fricas

map(x+->(sqrt(p1^2+p2^2+p3^2+1)*numer(x))/(sqrt(p1^2+p2^2+p3^2+1)*denom(x)),1/trace(%)*%)

$\label{eq49}\left[ \begin{array}{cccc} {{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 2}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}&{p 1 \over 2}&{p 2 \over 2}&{p 3 \over 2} \ -{p 1 \over 2}& -{{{p 1}^{2}}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}& -{{p 1 \ p 2}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}& -{{p 1 \ p 3}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}} \ -{p 2 \over 2}& -{{p 1 \ p 2}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}& -{{{p 2}^{2}}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}& -{{p 2 \ p 3}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}} \ -{p 3 \over 2}& -{{p 1 \ p 3}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}& -{{p 2 \ p 3}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}& -{{{p 3}^{2}}\over{{2 \ {\sqrt{{{p 3}^{2}}+{{p 2}^{2}}+{{p 1}^{2}}+ 1}}}+ 2}}$

(49)

Type: Matrix(Expression(Integer))

fricas

trace %

$\label{eq50}1$

(50)

Type: Expression(Integer)

fricas

--(SS*RR+RR*SS)/dot(S,R)-SS-RR;
--map(Simplify,1/trace(%)*%)
--(UU*VV+VV*UU)/dot(U,V)-UU-VV;
--1/trace(%)*%
(UU*RR+RR*UU)/dot(U,R)-UU-RR;

Type: Matrix(Expression(Integer))

fricas

map(Simplify,1/trace(%)*%)

$\label{eq51}\left[ \begin{array}{cccc} {{{\cosh \left({3 \ u}\right)}+{4 \ {\cosh \left({2 \ u}\right)}}+{7 \ {\cosh \left({u}\right)}}+ 4}\over{{4 \ {\cosh \left({2 \ u}\right)}}+{8 \ {\cosh \left({u}\right)}}+ 4}}&{{-{\sinh \left({3 \ u}\right)}-{2 \ {\sinh \left({2 \ u}\right)}}-{\sinh \left({u}\right)}}\over{{4 \ {\cosh \left({2 \ u}\right)}}+{8 \ {\cosh \left({u}\right)}}+ 4}}& 0 & 0 \ {{{\sinh \left({3 \ u}\right)}+{2 \ {\sinh \left({2 \ u}\right)}}+{\sinh \left({u}\right)}}\over{{4 \ {\cosh \left({2 \ u}\right)}}+{8 \ {\cosh \left({u}\right)}}+ 4}}&{{-{\cosh \left({3 \ u}\right)}+{\cosh \left({u}\right)}}\over{{4 \ {\cosh \left({2 \ u}\right)}}+{8 \ {\cosh \left({u}\right)}}+ 4}}& 0 & 0 \ 0 & 0 & 0 & 0 \ 0 & 0 & 0 & 0$

(51)

Type: Matrix(Expression(Integer))