. 2020 Jul 20;9:130. doi: 10.1038/s41377-020-0331-y

Table 1.

Overview of symmetries discussed in this review

Symmetries	Operation
Time-reversal symmetry²¹ ( $T$ )	t → −t, x → x, E → E, H → −H
Inversion symmetry²¹ (or parity symmetry, $P$ )	x → −x, t → t, E → −E, H → H
Glide reflection symmetry²²	Reflection + translation ${\hat{G}}_{x} : (x, y, z) \to (1 / 2 - x, 1 / 2 + y, z)$
Screw symmetry²²	Rotation + translation along the rotational axis ${\hat{S}}_{x} : (x, y, z) \to (x + 1 / 2, - y, - z)$
Electromagnetic duality²³	E → −cB, cB → E, ε = αμ (α is a constant scalar)

The bold values indicate that the quantity is a vector