Antiunitary operator: Difference between revisions

no edit summary
for all <math>x</math> and <math>y</math> in <math>H_1</math>, where the horizontal bar represents the [[complex conjugate]]. If additionally one has <math>H_1 = H_2</math> then U is called an '''antiunitary operator'''.
Antiunitary operators are important in quantum theory because they are used to represent certain symmetries, such as [[T-symmetry#Time reversal in quantum mechanics|time- reversal]] and [C-symmetry|charge conjugation]] symmetry. Their fundamental importance in quantum physics is further demonstrated by [[Wigner's theorem]].
==Invariance transformations==