timereversallike

Timereversallike is a term used in physics, mathematics, and related fields to characterize phenomena or models that display a time-reversal–like symmetry or behavior. It denotes a looser notion than strict time-reversal invariance and is often used when a system is approximately reversible over a limited duration or under certain conditions.

A system is timereversallike if, when the time variable is reversed and the dynamics are evolved with the same governing laws, the observable state closely retraces its prior trajectory or remains statistically indistinguishable from the forward evolution within measurement error.

In numerical simulation, timereversallike tests help assess the reversibility of integrators and numerical accuracy. In physics, the concept can describe quasi-reversible processes where dissipative effects are weak or controlled, allowing near-reversibility over short timescales. It is distinct from exact time-reversal symmetry, which is a fundamental property of certain equations of motion.

Examples include elastic billiards with near-perfect elasticity, certain Hamiltonian systems with weak damping, or digital signal processing techniques that apply time reversal to signals for analysis. In quantum theory, timereversallike may refer to approximate symmetries in open systems or in semiclassical approximations.

See also: time reversal symmetry, reversible computing, time-reversal test, reversibility in dynamical systems.