update: auto commit

This commit is contained in:
2026-04-09 16:15:13 -04:00
parent ad28c073ec
commit 2d3415b383
+3 -3
View File
@@ -245,11 +245,11 @@
\begin{equation} \begin{equation}
\pdvt{u^I} + \tensor{A}{^i^I_J} \pdv{u^J}{x^i} = S^I, \pdvt{u^I} + \tensor{A}{^i^I_J} \pdv{u^J}{x^i} = S^I,
\end{equation} \end{equation}
where both $A$ and $S$ can depend on $u^I$ but not their derivatives. For any unit covector $\xi_i$, the \emph{Principal symbol} matrix is defined as $P(\xi) := \tensor{A}{^i^I_J} \xi_i$. where both $A$ and $S$ can depend on $u^I$ but not their derivatives. For any unit covector $\xi_i$, the \emph{Principal symbol} matrix is defined as $\tensor{P}{^I_J}(\xi) := \tensor{A}{^i^I_J} \xi_i$.
The system is said to be: The system is said to be:
\begin{itemize} \begin{itemize}
\item \emph{weekly hyperbolic} if for any $\xi_i$, $P(\xi)$ has only real eigenvalues. \item \emph{weekly hyperbolic} if for any $\xi_i$, $\tensor{P}{^I_J}(\xi)$ has only real eigenvalues.
\item \emph{strongly hyperbolic} if for any $\xi_i$, $P(\xi)$ has only real eigenvalues and a complete set of eigenvectors, i.e., it is diagonalizable. \item \emph{strongly hyperbolic} if for any $\xi_i$, $\tensor{P}{^I_J}(\xi)$ has only real eigenvalues and a complete set of eigenvectors, i.e., it is diagonalizable.
\item \emph{symmetrically hyperbolic} if there exists a positive definite symmetrizer matrix $H_{IJ}$ such that $H_{IK} \tensor{A}{^i^K_J}$ is symmetric for each $i$. \item \emph{symmetrically hyperbolic} if there exists a positive definite symmetrizer matrix $H_{IJ}$ such that $H_{IK} \tensor{A}{^i^K_J}$ is symmetric for each $i$.
\end{itemize} \end{itemize}
\end{frame} \end{frame}