# Properties

 Label 1.4.F.4.1a Name $$C_{4,1}$$ Weight $1$ Degree $4$ Real dimension $1$ Components $4$ Contained in $$\mathrm{USp}(4)$$ Identity component $$\mathrm{U}(1)_2$$ Component group $$C_4$$

## Invariants

 Weight: $1$ Degree: $4$ $\mathbb{R}$-dimension: $1$ Components: $4$ Contained in: $\mathrm{USp}(4)$ Rational: yes

## Identity component

 Name: $\mathrm{U}(1)_2$ $\mathbb{R}$-dimension: $1$ Description: $\left\{\begin{bmatrix}\alpha I_2&0\\0&\bar\alpha I_2\end{bmatrix}: \alpha\bar\alpha = 1,\ \alpha\in\mathbb{C}\right\}$ Symplectic form: $\begin{bmatrix}0&I_2\\-I_2&0\end{bmatrix}$ Hodge circle: $u\mapsto\mathrm{diag}(u, u,\bar u,\bar u)$

## Component group

 Name: $C_4$ Order: $4$ Abelian: yes Generators: $\begin{bmatrix}0&0&0&\zeta_8\\0&0&-\zeta_8^7&0\\0&-\zeta_8^7&0&0\\\zeta_8&0&0&0\end{bmatrix}$

## Moment sequences

$x$ $\mathrm{E}[x^{0}]$ $\mathrm{E}[x^{1}]$ $\mathrm{E}[x^{2}]$ $\mathrm{E}[x^{3}]$ $\mathrm{E}[x^{4}]$ $\mathrm{E}[x^{5}]$ $\mathrm{E}[x^{6}]$ $\mathrm{E}[x^{7}]$ $\mathrm{E}[x^{8}]$ $\mathrm{E}[x^{9}]$ $\mathrm{E}[x^{10}]$ $\mathrm{E}[x^{11}]$ $\mathrm{E}[x^{12}]$
$a_1$ $1$ $0$ $2$ $0$ $24$ $0$ $320$ $0$ $4480$ $0$ $64512$ $0$ $946176$
$a_2$ $1$ $1$ $5$ $22$ $115$ $606$ $3314$ $18348$ $102883$ $581494$ $3308470$ $18920628$ $108665902$

## Moment simplex

 $\left(\mathrm{E}\left[a_1^{e_1}a_2^{e_2}\right]:\sum ie_i=2\right)\colon$ $\left(\mathrm{E}\left[a_1^{e_1}a_2^{e_2}\right]:\sum ie_i=4\right)\colon$ $\left(\mathrm{E}\left[a_1^{e_1}a_2^{e_2}\right]:\sum ie_i=6\right)\colon$ $\left(\mathrm{E}\left[a_1^{e_1}a_2^{e_2}\right]:\sum ie_i=8\right)\colon$ $\left(\mathrm{E}\left[a_1^{e_1}a_2^{e_2}\right]:\sum ie_i=10\right)\colon$ $\left(\mathrm{E}\left[a_1^{e_1}a_2^{e_2}\right]:\sum ie_i=12\right)\colon$ $1$ $2$ $5$ $10$ $24$ $22$ $52$ $128$ $320$ $115$ $278$ $696$ $1760$ $4480$ $606$ $1516$ $3840$ $9792$ $25088$ $64512$ $3314$ $8388$ $21424$ $54976$ $141568$ $365568$ $946176$

## Moment matrix

$\mathrm{E}\left[\chi_i\chi_j\right] = \begin{bmatrix}1&0&0&1&0&2&0&3&0&2\\0&2&0&0&6&0&6&0&12&0\\0&0&4&4&0&5&0&13&0&12\\1&0&4&9&0&11&0&24&0&18\\0&6&0&0&20&0&22&0&42&0\\2&0&5&11&0&16&0&30&0&23\\0&6&0&0&22&0&26&0&48&0\\3&0&13&24&0&30&0&77&0&61\\0&12&0&0&42&0&48&0&92&0\\2&0&12&18&0&23&0&61&0&52\end{bmatrix}$

$\ \ \ \mathrm{E}\left[\chi_i^2\right] = \begin{bmatrix}1&2&4&9&20&16&26&77&92&52\end{bmatrix}$

## Event probabilities

$-$$a_2\in\mathbb{Z}$$a_2=-2$$a_2=-1$$a_2=0$$a_2=1$$a_2=2$
$-$$1$$1/2$$0$$0$$1/2$$0$$0 a_1=0$$3/4$$1/2$$0$$0$$1/2$$0$$0$