On Walsh series with monotone coefficients
Gegham Grigor'evich Gevorkyan, Karen Arshaluicobich Navasardyan · Izvestiya Mathematics · 1999
We prove that if and then the Walsh series has the following property. For any measurable function which is finite almost everywhere, there are numbers such that the series converges to almost everywhere. This assertion complements and strengthens previously known results about universal Walsh series and Walsh null-series.