$b^2$b^2

$b^{0{,}25}$b^{0{,}25}

$\displaystyle b^{ \frac{8}{3} }$\displaystyle b^{ \frac{8}{3} }

$\displaystyle b^{ \frac{4}{3} }$\displaystyle b^{ \frac{4}{3} }