Temporal symmetry in quantum mechanics: is the microworld blind to the passage of time?

CRISTIAN LÓPEZ

La Plata

Congreso; VI Conference of Foundations of Quantum Mechanics; 2016

IFLP - CONICET

The problem of the arrow of time owes its origin to the intuitive asymmetry between past and future we experience in daily life. From the philosophy of physics point of view, the goal is to ground this intuition on physics by finding a physical correlate to that time-asymmetry. Usually, the clue is to find laws that are non-invariant under time-reversal: those laws would embody time-asymmetry in the context of the physical theories they belong to.In this presentation, the problem of the arrow of time in quantum mechanics will be taken into account. Firstly, I will show there is truly a serious problem when time-reversal operator is carefully thought out in quantum mechanics: at least, two kinds of time-reversal operators can be suitably established in the theory, according to which quantum mechanics turns out to be time invariant and time non-invariant at the same time. Then, I will argue that the commonly accepted way to define a time reversal operator in quantum mechanics (time reversal plus complex conjugation) begs the question about the problem of the arrow of time ?this kind of operator is built upon the assumption that temporal symmetry is a well-established symmetry of quantum mechanics, thus the problem of the arrow of time would be meaningless.