II. Lower semi-continuity of the area
Published online by Cambridge University Press: 24 October 2008
In 1914 Carathéodory defined m–dimensional measure in n–dimensional space. He considered one-dimensional measure as a generalization of length and he proved that the length of a rectifiable curve coincides with its one-dimensional measure.
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‡ The surface quoted above has an important bearing on the classical problem of the minimum value of the area of the surface of a solid, whose volume has a fixed value. It gives the answer that if the L. -F. definition is adopted, the area may be as small as we please. Since my paper was published it has been pointed out more than once that if the interior volume is constant then the old answer remains valid. Of course, I have never said that any application, past or future, of the L. F. definition has led or would lead necessarily to unexpected results.
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