Projections onto translation-invariant subspaces of $H\sp 1({\bf R})$
Projections onto translation-invariant subspaces of $H\sp 1({\bf R})$
Recently I. Klemes has characterized the complemented translation-invariant subspaces of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper H Superscript 1 Baseline left-parenthesis double-struck upper T right-parenthesis"> <mml:semantics> <mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mi>H</mml:mi> <mml:mn>1</mml:mn> </mml:msup> </mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="double-struck">T</mml:mi> </mml:mrow> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:annotation encoding="application/x-tex">{H^1}(\mathbb {T})</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. In …