Symmetry: a bridge between nature and culture

Are symmetries discovered or rather invented by humans ? The stand you may take firmly here reveals a lot of your epistemological position. Conversely, the arguments you may forge for answering to this question, or to one of its numerous narrower or broader variations, shape your whole philosophical thoughts; not specifically about science, by the way. I will try to show how physics helps to (re)consider this issue.

An alternative proof of Wigner theorem on quantum transformations based on elementary complex analysis

According to Wigner theorem, transformations of quantum states which preserve the probabilities are either unitary or antiunitary. This short communication presents an elementary proof of this theorem that significantly departs from the numerous ones already existing in the literature. The main line of the argument remains valid even in quantum field theory where Hilbert spaces are non-separable.