标题：On the continuity of principal eigenvalues for boundary value
problems with indefinite weight function with respect to radius
of balls in <mml:math alttext="$\mathbb{R}^N$" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mi>ℝ</mml:mi><mml:mrow><mml:mi>N</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math>
期刊名称：International Journal of Mathematics and Mathematical Sciences
印刷版ISSN：0161-1712
电子版ISSN：1687-0425
出版年度：2002
卷号：29
DOI：10.1155/S0161171202007147
出版社：Hindawi Publishing Corporation
摘要：We investigate the continuity of principal eigenvalues (i.e.,
eigenvalues corresponding to positive eigenfunctions) for the
boundary value problem −Δu(x)=λg(x)u(x), x∈BR(0);u(x)=0, |x|=R, where BR(0) is a ball in ℝN, and g is a smooth function, and we show that λ1
