Characterizations of positive selfadjoint extensions
نویسندگان
چکیده
منابع مشابه
ACTA UNIVERSITATIS APULENSIS No 15/2008 CHARACTERIZATIONS OF NONNEGATIVE SELFADJOINT EXTENSIONS
The set of all nonnegative selfadjoint extensions of a nonnegative linear relation (multi-valued operator) is described by using a partial order defined on the set of the corresponding quadratic forms. This characterization leads to a generalization of a result due to M.G. Krĕın. 2000 Mathematics Subject Classification: 47A06, 47A20, 47B25, 47A63.
متن کاملRank One Perturbations, Approximations, and Selfadjoint Extensions
of a semibounded selfadjoint operator A are studied with the help of distribution theory. It is shown that such perturbations can be defined for finite values of : even if the element . does not belong to H&1(A). Approximations of the rank one perturbations are constructed in the strong operator topology. It is proven that rank one H&2 perturbations can be defined uniquely for the homogeneous o...
متن کاملCharacterizations of various matching extensions in graphs
Let n be a positive integer with n $; (V(O)-2)/2. A graph G is nextendable if it contains a set of n independent edges and every set of n independent edges can be extended to a perfect matching of G. In this paper, we give a characterization of n-extendable graphs. The characterizations of other matching extension are also discussed.
متن کاملComputing power indices: Multilinear extensions and new characterizations
Johnston (1978), Deegan and Packel (1979), and Holler (1982) proposed three power indices for simple games: Johnston index, Deegan-Packel index, and the Public Good Index. In this paper, methods to compute these indices by means of the multilinear extension of the game are presented. Furthermore, a new characterization of the Public Good Index is given. Our methods are applied to two real-world...
متن کاملNon-selfadjoint Perturbations of Selfadjoint Operators in 2 Dimensions I
This is the first in a series of works devoted to small non-selfadjoint perturbations of selfadjoint h-pseudodifferential operators in dimension 2. In the present work we treat the case when the classical flow of the unperturbed part is periodic and the strength ǫ of the perturbation is ≫ h (or sometimes only ≫ h2) and bounded from above by hδ for some δ > 0. We get a complete asymptotic descri...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the American Mathematical Society
سال: 2007
ISSN: 0002-9939
DOI: 10.1090/s0002-9939-06-08590-x