Abstract:
In the classical space $L^2(-\pi,\pi)$ there exists the unconditional basis $\{e^{ikt}\}$ ($k$ is integer). In the work we study the existence of unconditional bases in weighted Hilbert spaces $L^2(I,\exp h)$ of the functions square integrable on an interval $I$ in the real axis with the weight $\exp(- h)$, where $h$ is a convex function. We obtain conditions showing that unconditional bases of exponents can exist only in very rare cases.
Keywords:Riesz bases, unconditional bases, series of exponents, Hilbert space, Fourier–Laplace transform.
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