From 8eb4857d9a3d05825e8d96f396526d7de4ae81fd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Gi=C3=B9=20Marcer?= Date: Fri, 5 Jun 2020 23:30:39 +0200 Subject: [PATCH] slides: move things from notes-moyal.md to the sections --- slides/misc/notes-moyal.md | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 slides/misc/notes-moyal.md diff --git a/slides/misc/notes-moyal.md b/slides/misc/notes-moyal.md new file mode 100644 index 0000000..5bb921d --- /dev/null +++ b/slides/misc/notes-moyal.md @@ -0,0 +1,34 @@ +The Moyal distribution, which is a steepest descent approximation of the +Landau distribition, is defines as: +$$ + \exp \left( - \frac{x - \mu }{2 \sigma} + - \frac{1}{2} \exp \left( - \frac{x -\mu}{\sigma} \right) \right) +$$ +Mean $m$ and variance $\sigma$: +$$ + m = \mu + \sigma [ \gamma + \ln(2) ] \et \sigma = \frac{\pi^2 \sigma^2}{2} +$$ +Median: +$$ + \mu - \sigma \left[ 2 \text{erf}^{-1} \left( \frac{1}{2} \right)^2 \right] +$$ +skewness and kurtosis are constant: +$$ + s = \frac{28 \sqrt{2} Z(3)]{\pi^3} \et k = 7 +$$ +max value: +$$ + \frac{1}{\sqrt{2 e \pi}} +$$ +cdf: +$$ + \text{erf} \left( \frac{\exp \left( + - \frac{x - \mu}{2 \sigma} \right)}{\sqrt{2}} \right) +$$ + +$\mu$ is the location parameter and $\sigma$ is the scale parameter. +The Moyal distribution was first proposed in a 1955 paper by physicist J. E. +Moyal. The distribution models the energy lost by a fast charged particle +(and hence the number of ion pairs produced) during ionization. Historically, +the Moyal distribution has been utilized in the approximation of the Landau +Distribution and has since found use in modeling a wide array of phenomena.