Properties

Label 3.2.B.d1
  
Name \(N(\mathrm{U}(1))\)
Weight $3$
Degree $2$
Real dimension $1$
Components $2$
Contained in \(\mathrm{U}(2)\)
Identity component \(\mathrm{U}(1)\)
Component group \(D_{1}\)

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Invariants

Weight:$3$
Degree:$2$
$\mathbb{R}$-dimension:$1$
Components:$2$
Contained in:$\mathrm{U}(2)$
Rational:yes

Identity component

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

Component group

Name:$D_{1}$
Order:$2$
Abelian:yes
Generators:$\left\{\begin{bmatrix} 0 & 1\\ -1 & 0\end{bmatrix}, \begin{bmatrix} 1 & 0 \\ 0 & \zeta_{1}\end{bmatrix}\right\}$

Subgroups and supergroups

Maximal subgroups:
Minimal supergroups:$\mathrm{U}(1)[D_{2}]$, $\mathrm{U}(1)[D_{3}]$, $\mathrm{U}(1)[D_{5}]$, $\ldots$

Moment sequences

$x$ $\mathrm{E}[x^{0}]$ $\mathrm{E}[x^{1}]$ $\mathrm{E}[x^{2}]$ $\mathrm{E}[x^{3}]$ $\mathrm{E}[x^{4}]$ $\mathrm{E}[x^{5}]$ $\mathrm{E}[x^{6}]$ $\mathrm{E}[x^{7}]$ $\mathrm{E}[x^{8}]$ $\mathrm{E}[x^{9}]$ $\mathrm{E}[x^{10}]$ $\mathrm{E}[x^{11}]$ $\mathrm{E}[x^{12}]$
$a_1$ $1$ $0$ $1$ $0$ $3$ $0$ $10$ $0$ $35$ $0$ $126$ $0$ $462$