next previous
Up: Understanding radio polarimetry


11 Appendix: Mathematical theory


 

 
Table 3: Algebraic entities and their notation as used in this paper
Entity Vector $2 \times 2\ $Matrix Stokes vector Quaternion
         
Coherency $ \vec{e}_{jk \vphantom{'}}= \vec{e}_{j \vphantom{'}}\otimes \vec{e}_{k \vphantom{'}}^* $ $\! \vec{E}_{jk \vphantom{'}}= \vec{e}_{j \vphantom{'}}\vec{e}_{k \vphantom{'}}^{\dagger}$ $ \vec{s}_{jk \vphantom{'}}\!=\!
\left( \begin{array}{cccc}
1 &0 &0 &1
\\ 1 ...
...\ 0 &1 &1 &0
\\ 0 &-i &i &0 \end{array} \right)
\!\vec{e}_{jk \vphantom{'}}$  
         
General element $ \left( \begin{array}{l} a_{11}\\ a_{12}\\ a_{21}\\ a_{22} \end{array} \right) $ $\! \begin{array}{l}
\vec{A}= \left( \begin{array}{cc} a_{11} &a_{12}
\\ a_{21...
... +a_1 & a_2-ia_3
\\ a_2+ia_3 & a - a_1\end{array} \right)
\end{array} \!\!\!$ $ \left( \begin{array}{c} a \\
\!\mbox{- -}\! \\ a_1\\ a_2\\ a_3 \end{array} \...
...left( \begin{array}{c} a \\
\!\!\mbox{- -}\!\! \\ \vec{a}\end{array} \right) $ $ \begin{array}{l}
[a+\vec{a}{]},
\\ %
\qquad \vec{a}\equiv
\left( \begin{array}{ccc} a_1 &a_2 &a_3 \end{array} \right)
\end{array} $
         
Scalar part     intensity a $ [a+\vec{0}] \equiv
[a{]} \equiv a $
         
Vector part     polvector $ \vec{a}$ $ [0+\vec{a}] \equiv
[\vec{a}{]} \not\equiv \vec{a}$
         
Base for vector part   % latex2html id marker 4490
$ \mathbf{Q}, \mathbf{U}, \vec{V}, \mbox{\ \ Eq. (\ref{.eq.Pauli}) }$ % latex2html id marker 4492
$\vec{1}_{\mathbf{q}}, \vec{1}_{\mathbf{u}},
\vec{1}_{\mathbf{v}}, \mbox{\ \ Eq. (\ref{.eq.quv}) }$ $[\vec{1}_{\mathbf{q}}{]}, [\vec{1}_{\mathbf{u}}{]},
[\vec{1}_{\mathbf{v}}{]} $
         
Alternate base   % latex2html id marker 4496
$ \vec{V}, \mathbf{Q}, \mathbf{U}, \mbox{\ \ Eq. (\ref{.eq.A=a0I+a1V...}) }$ $\vec{1}_{\mathbf{v}}, \vec{1}_{\mathbf{q}}, \vec{1}_{\mathbf{u}}$ $[\vec{1}_{\mathbf{v}}{]}, [\vec{1}_{\mathbf{q}}{]},
[\vec{1}_{\mathbf{u}}{]} $
         
Unit element   I   [1] = 1
         
Conjugation   $\vec{A}^{\dagger}$ $\left( \begin{array}{c} a^* \\
\!\!\mbox{- -}\!\! \\ \vec{a}^* \end{array} \right) $ $ [a^* + \vec{a}^*{]} $
         
Multiplication   $ \vec{A}\vec{B}$   Eq. (25)
         
Unimodular unitary matrix   $\vec{Y}$   $ \cos\eta + i\vec{1}_{\vec{y}}\sin\eta $
         
Unimodular positive hermitian matrix   $\vec{H}$   $ \cosh\gamma
+ \vec{1}_{\vec{h}}\sinh\gamma $
         



next previous
Up: Understanding radio polarimetry

Copyright The European Southern Observatory (ESO)