Astrophysics (index)

Linear Theory

(theory of operators satisfying the property of superposition)

Linear Theory, i.e., the study of Linear Systems concerns operators (functions) that satisfy the property of Superposition, i.e., if function F is such that A = F(x) and B = F(y), then A + B = F(x+y).

Such a system has nice properties when the Fourier Transform is applied: the sum of sine waves according to the transform's output matches the input.

Linear Theory is used in signal processing and analysis of time-variant functions.