Elliptic problems involving an indefinite weight
Elliptic problems involving an indefinite weight
We consider a selfadjoint elliptic eigenvalue problem, which is derived formally from a variational problem, of the form <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper L u equals lamda omega left-parenthesis x right-parenthesis u"> <mml:semantics> <mml:mrow> <mml:mi>L</mml:mi> <mml:mi>u</mml:mi> <mml:mo>=</mml:mo> <mml:mi>λ<!-- λ --></mml:mi> <mml:mi>ω<!-- ω --></mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>x</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mi>u</mml:mi> </mml:mrow> …