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Next: Appendix C: Adjoint-state tomography Up: Li et al.: DSR Previous: Appendix A: Causal discretization

Appendix B: Frechét derivative of DSR tomography

To derive the Frechét derivative, we start from equations 13 and 14. Applying $\partial / \partial w_s$ to both sides of equation 13 results in

$\displaystyle D_z \frac{\partial t^{dsr}}{\partial w_s}$ $\textstyle =$ $\displaystyle - \frac{1}{2 \sqrt{w_s - D_s t^{dsr} \cdot D_s t^{dsr}}}$  
  $\textstyle +$ $\displaystyle \left(\frac{D_s t^{dsr} \cdot D_s}{\sqrt{w_s - D_s t^{dsr} \cdot ...
..._r t^{dsr} \cdot D_r t^{dsr}}}\right)
\frac{\partial t^{dsr}}{\partial w_s}\;.$ (35)

Analogously
$\displaystyle D_z \frac{\partial t^{dsr}}{\partial w_r}$ $\textstyle =$ $\displaystyle - \frac{1}{2 \sqrt{w_r - D_r t^{dsr} \cdot D_r t^{dsr}}}$  
  $\textstyle +$ $\displaystyle \left(\frac{D_s t^{dsr} \cdot D_s}{\sqrt{w_s - D_s t^{dsr} \cdot ...
..._r t^{dsr} \cdot D_r t^{dsr}}}\right)
\frac{\partial t^{dsr}}{\partial w_r}\;.$ (36)

Inserting equations B-1 and B-2 into 14 and regrouping the terms, we prove equation 15
\begin{displaymath}
J^{dsr} = B^{-1} (C_s + C_r)\;,
\end{displaymath} (37)

where
\begin{displaymath}
B = D_z
- \left( \frac{D_s t^{dsr} \cdot D_s}{\sqrt{w_s - D...
...ot D_r}{\sqrt{w_r - D_r t^{dsr} \cdot D_r t^{dsr}}} \right)\;,
\end{displaymath} (38)

and
\begin{displaymath}
C_s =
- \frac{1}{2 \sqrt{w_s - D_s t^{dsr} \cdot D_s t^{dsr}}}\,
\frac{\partial w_s}{\partial w}\;;
\end{displaymath} (39)


\begin{displaymath}
C_r =
- \frac{1}{2 \sqrt{w_r - D_r t^{dsr} \cdot D_r t^{dsr}}}\,
\frac{\partial w_r}{\partial w}\;.
\end{displaymath} (40)

At the singularity of DSR eikonal equation, the operators $B$, $C_s$ and $C_r$ take simpler forms and can be derived directly from equation 3.


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Next: Appendix C: Adjoint-state tomography Up: Li et al.: DSR Previous: Appendix A: Causal discretization

2013-10-16