The property of positive fourier series.
89003
Finding a trigonometric polynomial
144104
Show that a positive operator on a complex Hilbert space is self-adjoint
136635
Proving that the Fourier Basis is complete for C(R/$2*\pi$ , C) with $L^2$ norm
100606
Fourier transform of a radial function is radial
99117
Existence of a sequence of positive continuous functions on $\mathbb R$ which is unbounded precisely on $\mathbb Q$
56818
Prove that if $A$ is positive, then $\exists\;\alpha>0$ such that $\langle Ax, x \rangle\geq \alpha|x|^2$ for $x\in\Bbb{R}^n$
58321
Convergence of "alternating" harmonic series where sign is +, --, +++, ----, etc.
120676
A certain element which makes functionals positive
151919
Cauchy-Product of non-absolutely convergent series
79132
Fourier transform of modified Bessel function of the second kind
52137
Equivalence of conditions for Convergence of Non-negative Random Series
10478
Matrix reciprocal positive to prove $λ_{max⁡}=n$
93312
Fourier transform of the indicator of the unit ball
34590
Fourier series of Log sine and Log cos
124335
An identity for Fourier transform of measure
9944
Fourier series identity
137289
Applying Fourier transform to a gaussian