E. Zikkos

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math.FA2025

On Markushevich bases ${x^{I^»_{n}}}_{n = 1}^{\infty}$ for their closed span in weighted $L^{2} (A)$ spaces over sets $A \subset [0, \infty)$ of positive Lebesgue measure, hereditary completeness, and moment problems

Elias Zikkos

Inspired by the work of Borwein and Erdelyi \cite{BE1997JAMS} on generalizations of MÃ¼ntz's theorem, we investigate the properties of the system ${x^{I^»_{n}}}_{n = 1}^{\infty}$ in w…

math.FA2025

On Strong Markushevich bases ${t^{I^»_{n}}}_{n = 1}^{\infty}$ in their closed span in $L^{2} (0, 1)$ and characterizing a subspace of $H^{2} (D)$

Elias Zikkos

Let $I^ = {I^»_{n}}_{n = 1}^{\infty}$ be a strictly increasing sequence of positive real numbers such that $\sum_{n = 1}^{\infty} \frac{1}{I ^ » _{n}} < \infty$ and $in f (I^»_{n + 1} - I^»_{n}) > 0$ . We inv…

math.FA2024

On exact systems ${t^{I^} \pm \cdot e^{2 I ¨ in t}}_{n \in Z ∖ A}$ in $L^{2} (0, 1)$ which are not Schauder Bases and their generalizations

Elias Zikkos

Let ${e^{i I^»_{n} t}}_{n \in Z}$ be an exponential Schauder Basis for $L^{2} (0, 1)$ , for $I^»_{n} \in R$ , and let ${r_{n} (t)}_{n \in Z}$ be its dual Schauder Basis.…

On Markushevich bases {xI^»n​}n=1∞​ for their closed span in weighted L2(A) spaces over sets A⊂[0,∞) of positive Lebesgue measure, hereditary completeness, and moment problems

On Strong Markushevich bases {tI^»n​}n=1∞​ in their closed span in L2(0,1) and characterizing a subspace of H2(D)

On exact systems {tI^±⋅e2I¨int}n∈Z∖A​ in L2(0,1) which are not Schauder Bases and their generalizations

On Markushevich bases ${x^{I^»_{n}}}_{n = 1}^{\infty}$ for their closed span in weighted $L^{2} (A)$ spaces over sets $A \subset [0, \infty)$ of positive Lebesgue measure, hereditary completeness, and moment problems

On Strong Markushevich bases ${t^{I^»_{n}}}_{n = 1}^{\infty}$ in their closed span in $L^{2} (0, 1)$ and characterizing a subspace of $H^{2} (D)$

On exact systems ${t^{I^} \pm \cdot e^{2 I ¨ in t}}_{n \in Z ∖ A}$ in $L^{2} (0, 1)$ which are not Schauder Bases and their generalizations