31 Jul 2025

Multivariate Vector Valued Beurling Algebra Analogues Of Theorems Of Wiener And Ε»elazko


Authors :- PA Dabhi, KB Solanki
Publication :- Communications of the Korean Mathematical Society, 2025

If 0 < p ≀ 1, πœ” is a weight on β„€2, π’œ is a unital complex Banach algebra and if f is a continuous π’œ valued function on 𝕋2 such that ${\sum{_{{(m,n)}{\in}{\mathbb{Z}}^2}}\,{\parallel}{\hat{f}}(m,n){\parallel}^p{\omega}(m,n)\,<\,{\infty}$, where ${\hat{f}}(m,n)$ are Fourier coefficients of f, and f(z, w) is left invertible in π’œ for all (z, w) ∈ 𝕋2, then it is shown that there is a weight 𝜈 on β„€2 and a continuous function g : 𝕋2 β†’ π’œ such that 1 ≀ 𝜈 ≀ πœ”, 𝜈 is constant if and only if πœ” is constant, ${\sum{_{{(m,n)}{\in}{\mathbb{Z}}^2}}\,{\parallel}{\hat{g}}(m,n){\parallel}^p{\omega}(m,n)\,<\,{\infty}$ and g is a left inverse of f. A similar result is obtained for a continuous function f from π•‹βˆž (the countable copies of 𝕋) to π’œ.

DOI Link :- https://doi.org/10.4134/CKMS.c240243