stationary phase

The stationary phase refers to points in a mathematical or physical process where the behavior of a system changes gradually, and certain features remain stable over time. In contexts like wave analysis or integrals, it indicates the location where phase variations are minimal, allowing the main contributions to a result to originate there. Essentially, it's where oscillations or changes are slowest, helping us focus on key areas that dominate the system's behavior. This concept helps simplify complex problems by identifying the regions that have the most significant impact on the outcome.