Spectral Density
- Modern Physics -
Quantum Mechanics Dictionary
Definition
A quantum mechanics concept defining a model element, mathematical object, or experimental method used to predict measurable outcomes. It applies when required assumptions and definitions are specified and yields computable probabilities and expectation values. It does not ensure correctness without validation of approximations, numerical stability, and consistency of units and conventions.
Spectral Density
Natural & Formal Sciences Dictionary
Definition
A function that allocates a nonnegative weight to each frequency value characterizing how variance or power of a stationary signal or process is distributed across temporal frequencies, serving as the frequency-domain description of second-order structure.