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Integral inequalities for ovaloids in Euclidean space

Published online by Cambridge University Press:  26 February 2010

Th. Koufogiorgos
Affiliation:
Department of Mathematics, University of Ioannina, Ioannina 45332, Greece.
Ch. Baikoussis
Affiliation:
Department of Mathematics, University of Ioannina, Ioannina 45332, Greece.
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Extract

Let M be a smooth surface in Euclidean space E3 and L the Weingarten map. The fundamental forms I1, I2, I3,… on M are defined in terms of L and the usual inner product 〈, 〉 of E3 as follows. If X and Y are in the tangent space TPM of M (Pε M), then I1(X, Y) = 〈X, Y), I2(X, Y) = 〈LX, Y〉, I3(X, Y) = 〈L2X, Y), etc. Moreover, if M is convex, i.e., the Gaussian curvature K = k1k2, where ki, (i = l,2) are the principal curvatures of M, is everywhere positive, then one can also define on M the forms I0(X, Y) = 〈L−1X, Y), I−1,(X, Y) = 〈L−2X, Y), I−2(X, Y) = 〈 L−3X, Y) etc., where L−1 is the inverse of L. Since L is self-adjoint, the forms Im are, for any integer m, symmetric bilinear functions on TPM × TPM. Furthermore Im are C in the sense that if X and Y are vector fields with domain AM, then 〈 LmX, YP = 〉LmXP, YP) is a C real function on A. If the convex surface M is appropriately oriented, then the forms Im define metrics on M, which we also denote by 〈, 〉m (〈, 〉1)≡ 〈, 〉).

Type
Research Article
Copyright
Copyright © University College London 1987

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