Abstract
LetA 1,...,An andK bem×m symmetric matrices withK positive definite. Denote byC the convex hull of {A 1,...An}. Let {λ p (KA)} n1 be then real eigenvalues ofKA arranged in decreasing order. We show that maxλ p (KA) onC is attained for someA *=Σ = 1/n i for which at mostp(p+1)/2 of α i * do not vanish. We extend this result in several directions and consider applications to classes of integral equations.
Similar content being viewed by others
References
S. Friedland and Z. Nehari,Univalence conditions and Sturm-Liouville eigenvalues, Proc. Amer. Math. Soc.24 (1970), 595–603.
F.R. Gantmacher,The Theory of Matrices, I and II, Chelsea Publishing Company, New York, 1964.
F. R. Gantmacher and M. G. Krein,Oscillating Matrices and Kernels and Small Vibrations of Mechanical Systems, Moscow, 1950.
S. Karlin,Total Positivity, Vol. I, Stanford University Press, California, 1968.
S. Karlin,Total positivity, interpolation by splines and Green’s functions of differential operators, J. Approximation Theory4 (1971), 91–112.
S. Karlin,Some extremal problems for eigenvalues of certain matrix and integral operators, Advances in Math.9 (1972), 93–136.
Z. Nehari,Some eigenvalues estimates, J. Analyse Math.7 (1959), 79–88.
P. Nowosad,Isoperimetric eigenvalue problems in algebras, Comm. Pure Appl. Math.21 (1968), 401–465.
G. Pólya and M. Schiffer,Convexity of functionals by transplantation, J. Analyse Math.3 (1953/54), 245–345.
Author information
Authors and Affiliations
Additional information
This paper is based mainly on the author’s doctoral dissertation written at the Technion—Israel Institute of Technology, March 1971, under the direction of Professor B. Schwarz. I wish to thank Professor Schwarz for his advice and encouragement. I am also grateful to Professor S. Karlin for supplying simplifications of several of my arguments. Some extensions discussed here are joint results of Karlin and the author.
Rights and permissions
About this article
Cite this article
Friedland, S. Extremal eigenvalue problems for convex sets of symmetric matrices and operators. Israel J. Math. 15, 311–331 (1973). https://doi.org/10.1007/BF02787574
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02787574