Complexity of indefinite elliptic problems
Complexity of indefinite elliptic problems
This paper deals with the approximate solution of a linear regularly-elliptic 2<italic>m</italic>th-order boundary-value problem <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L u equals f"> <mml:semantics> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>u</mml:mi> <mml:mo>=</mml:mo> <mml:mi>f</mml:mi> </mml:mrow> <mml:annotation encoding="application/x-tex">Lu = f</mml:annotation> </mml:semantics> </mml:math> </inline-formula>, with <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="f element-of upper H Superscript r Baseline left-parenthesis …