intermittence

Intermittence refers to the quality or condition of being intermittent, characterized by alternating periods of activity and inactivity, occurrence and non-occurrence, or bursts of signal with intervening quiet. The term is used across disciplines to describe non-continuous temporal behavior that cannot be captured by a single steady state.

In physics and engineering, intermittence is a notable feature in systems exhibiting irregular switching between different states. In turbulence, for example, the flow shows intermittent bursts of intense fluctuations within a generally calmer background, a phenomenon often described as intermittence. A related concept, on-off intermittence, describes a process that toggles stochastically between near-zero (off) and burst (on) phases, typically influenced by noise and slowly varying parameters. In electronics and communications, intermittent signals produce bursts of activity separated by gaps, complicating detection and decoding.

In biology and neuroscience, intermittent activity appears as episodes of firing or signaling interspersed with quiescence, seen in neuronal networks or hormonal release patterns.

Modeling intermittence commonly uses two-state or multi-state stochastic processes, such as Markov chains, renewal processes with heavy-tailed inter-burst intervals, or dynamical systems with noise-induced switching. Metrics include burst duration distributions, duty cycle (the fraction of time in the active state), and inter-burst intervals.

Etymology: Intermittence derives from Latin intermittere, meaning to stop and begin again, through French intermittence, and into English.