Unitary operators

Unitary operators are mathematical tools used primarily in quantum mechanics to represent the evolution of quantum states. They preserve the total probability, meaning if you start with a certain likelihood of finding a particle in different states, that total likelihood remains the same after applying the operator. This property ensures that information is conserved in quantum processes. Think of a unitary operator like a reversible film that changes the appearance of scenes without losing any details, allowing you to go back to the original version without any loss of information.