Existence of double Walsh series universal in weighted $L_{\mu }^1[0,1{]}^2$ spaces

Abstract

In this paper we consider a question on existence of double Walsh series universal in weighted $L_{\mu }^1[0,1{]}^2$ spaces. We construct a weighted function $\mu (x,y)$ and a series by double Walsh system of the form $$\sum_{n,k=1}^\infty c_{n,k}W_n(x)W_k(y)\ \ \mbox{with} \ \ \sum_{n,k=1}^\infty \left | c_{n,k} \right|^q <\infty\ \mbox{for all}\ q>2,$$ which is universal in $L_{\mu }^1[0,1{]}^2$ concerning subseries with respect to convergence, in the sense of both spherical and rectangular partial sums.

appears in International Journal of Modern Mathematics, 2007. arXiv admin note: substantial text overlap with arXiv:1407.1495