Fluctuation theorem
= Fluctuation theorem
{wiki}
A fluctuation theorem compares the <probability> of a fluctuating <sample trajectory> with that of its reverse. Positive mean <entropy production> permits negative individual realizations: what is constrained is their relative <probability>, not a prohibition on every reversal. The finite statement below compares specified forward and reverse <probability laws>; replacing the reverse law by the forward law requires an additional symmetry. The <biased-step entropy production model> exhibits that symmetry exactly, while the <Crooks fluctuation theorem> compares two different driving protocols.