summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJaron Kent-Dobias <jaron@kent-dobias.com>2022-02-07 12:22:03 +0100
committerJaron Kent-Dobias <jaron@kent-dobias.com>2022-02-07 12:22:03 +0100
commit35f67091ec755281f38898aaff9b9d23610c43af (patch)
treebbb2b86ea762cf5262f6cd12bdae2f649372a80d
parentc560253e75777e7789bb596776ec41f70d0e368b (diff)
downloadJPA_55_434006-35f67091ec755281f38898aaff9b9d23610c43af.tar.gz
JPA_55_434006-35f67091ec755281f38898aaff9b9d23610c43af.tar.bz2
JPA_55_434006-35f67091ec755281f38898aaff9b9d23610c43af.zip
Changed order of paragraphs.
-rw-r--r--stokes.tex32
1 files changed, 16 insertions, 16 deletions
diff --git a/stokes.tex b/stokes.tex
index ce01b52..3c8af84 100644
--- a/stokes.tex
+++ b/stokes.tex
@@ -442,22 +442,6 @@ eigenvalue problem. If we did not know the eigenvalues were real, we could
still see it from the second implied equation, $(\beta\partial\partial\mathcal
S)^*v^*=\lambda v$, which is the conjugate of the first if $\lambda^*=\lambda$.
-The effect of changing the phase of $\beta$ is revealed by
-\eqref{eq:generalized.eigenproblem}. Writing $\beta=|\beta|e^{i\phi}$ and
-dividing both sides by $|\beta|e^{i\phi/2}$, one finds
-\begin{equation}
- \partial\partial\mathcal S(e^{i\phi/2}v)
- =\frac{\lambda}{|\beta|}e^{-i\phi/2}v^*
- =\frac{\lambda}{|\beta|}(e^{i\phi/2}v)^*
-\end{equation}
-Therefore, one only needs to consider solutions to the eigenproblem for the
-action alone, $\partial\partial\mathcal Sv_0=\lambda_0 v_0^*$, and then rotate the
-resulting vectors by a constant phase corresponding to half the phase of
-$\beta$ or $v(\phi)=v_0e^{-i\phi/2}$. One can see this in the examples of Figs. \ref{fig:1d.stokes} and
-\ref{fig:thimble.orientation}, where increasing the argument of $\beta$ from
-left to right produces a clockwise rotation in the thimbles in the
-complex-$\theta$ plane.
-
Something somewhat hidden in the structure of the real hessian but more clear
in its complex form is that each eigenvalue comes in a pair, since
\begin{equation}
@@ -474,6 +458,22 @@ real eigenvectors which determine its index in the real problem are accompanied
by $N$ purely imaginary eigenvectors, pointing into the complex plane and each
with the negative eigenvalue of its partner.
+The effect of changing the phase of $\beta$ is revealed by
+\eqref{eq:generalized.eigenproblem}. Writing $\beta=|\beta|e^{i\phi}$ and
+dividing both sides by $|\beta|e^{i\phi/2}$, one finds
+\begin{equation}
+ \partial\partial\mathcal S(e^{i\phi/2}v)
+ =\frac{\lambda}{|\beta|}e^{-i\phi/2}v^*
+ =\frac{\lambda}{|\beta|}(e^{i\phi/2}v)^*
+\end{equation}
+Therefore, one only needs to consider solutions to the eigenproblem for the
+action alone, $\partial\partial\mathcal Sv_0=\lambda_0 v_0^*$, and then rotate the
+resulting vectors by a constant phase corresponding to half the phase of
+$\beta$ or $v(\phi)=v_0e^{-i\phi/2}$. One can see this in the examples of Figs. \ref{fig:1d.stokes} and
+\ref{fig:thimble.orientation}, where increasing the argument of $\beta$ from
+left to right produces a clockwise rotation in the thimbles in the
+complex-$\theta$ plane.
+
These eigenvalues and vectors can be further related to properties of the
complex symmetric matrix $\beta\partial\partial\mathcal S$. Suppose that
$u\in\mathbb R^N$ satisfies the eigenvalue equation