Cases

Conditions

Bounds

5th case sparse matrix

$\left|a_0\right|+\cdots +\left|a_3\right|<1$

$\left|\lambda \right|\le 32$

Cauchy

${\Vert .\Vert }_{\infty }$

$\left|\lambda \right|\le 32$

Montel

${\Vert .\Vert }_1$

$\left|\lambda \right|\le 121$

Carmichel-Mason

${\Vert .\Vert }_2$

$\left|\lambda \right|\le 57.1139212$

Ovals of Cassini

$\gamma$ , $\delta$

$\left|\lambda \right|\le 32$

Dehmer

$M_1$ , ${\varphi }_2$

$\left|\lambda \right|\le 12.66$