An infinite series of trigonometric functions that represents an expansion or approximation of a periodic function, used in Fourier analysis.
- ‘In mathematics he worked on the calculus of variations, Fourier series, function spaces, Hamiltonian geometrical optics, Schrödinger wave mechanics, and relativity.’
- ‘From this he was able to prove that if a function was representable by a trigonometric series then this series is necessarily its Fourier series.’
- ‘He carried out many important and fruitful investigations in number theory, in the theory of Bessel functions and of Fourier series, in ordinary and partial differential equations, and in analytical mechanics and potential theory.’
- ‘His work led him to study the acceleration of convergence of Fourier series and the approximate solutions to differential equations.’
- ‘Hardy's interests covered many topics of pure mathematics - Diophantine analysis, summation of divergent series, Fourier series, the Riemann zeta function, and the distribution of primes.’