Sharp estimates for Lebesgue constants
Sharp estimates for Lebesgue constants
Suppose <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C subset-of upper R Superscript upper N"> <mml:semantics> <mml:mrow> <mml:mi>C</mml:mi> <mml:mo>⊂<!-- ⊂ --></mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mi>R</mml:mi> <mml:mi>N</mml:mi> </mml:msup> </mml:mrow> </mml:mrow> <mml:annotation encoding="application/x-tex">C \subset {R^N}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> is a closed convex bounded body containing 0 in its interior. If <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" …