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721.
Gesztesy and Simon recently have proven the existence of the strong resolvent limit A, for A, = A + (·), where A is a self-adjoint positive operator,
being the A-scale). In the present note it is remarked that the operator A, also appears directly as the Friedrichs extension of the symmetric operator
:=A \{f
(A)| f,=0\}. It is also shown that Krein's resolvents formula: (A_b,-z)-1 =(A-z)-1+
(·,
) z, with b=b-(1+z) (z,-1),z= (A-z)-1 defines a self-adjoint operator Ab, for each
and b R1. Moreover it is proven that for any sequence n
which goes to in
there exists a sequence n0 such that
Ab, in the strong resolvent sense. 相似文献
722.
Schehrazad Selmane. 《Mathematics of Computation》1999,68(225):333-344
We give the lists of all non-primitive number fields of degree eight having two, four and six real places of discriminant less than 6688609, 24363884 and 92810082, respectively, in absolute value. For each field in the lists, we give its discriminant, the discriminant of its subfields, a relative polynomial generating the field over one of its subfields and its discriminant, the corresponding polynomial over , and the Galois group of its Galois closure.
723.
本文研究对角占优矩阵奇异-非奇异的充分必要条件.基于Taussky定理,本文得出,可约对角占优矩阵的奇异性由其独立Frobenius块的奇异性决定,从而将这一问题化为不可约对角占优矩阵的奇异-非奇异性问题;运用Taussky定理研究奇异不可约对角占优矩阵的相似性和酉相似性,获得这类矩阵元素辐角间的关系;并与Taussky定理给出的这类矩阵元素模之间的关系结合在一起,研究不可约对角占优矩阵奇异的充分必要条件;最后给出不可约对角占优矩阵奇异-非奇异性的判定方法. 相似文献
724.
In a recent paper Dubrovin et al. (1998), it is proved that the genus two free energy of an arbitrary semisimple Frobenius manifold can be represented as a sum of contributions associated with dual graphs of certain stable algebraic curves of genus two plus the so called genus two -function, and for a certain class of Frobenius manifolds it is conjectured that the associated genus two -functions vanish. In this paper, we prove this conjecture for the Frobenius manifolds associated with simple singularities of type A. 相似文献
726.
文章类似于A-上环(coring)给出T-余单子(comonad)的一些性质(这里A是代数,T是单子(monad)).首先定义了实(firm)单子等相关概念,其次研究了与Frobenius函子等价的两个命题,最后给出了与余单子可分等价的五个命题. 相似文献
727.
设0→I→A■B→0为C~*-代数扩张,其中I为AF-代数,A为有单位元的C~*-代数.设D为一类AF-代数.本文利用投影元的保序提升和K_0-群的归纳极限来研究K_0(D)到K_0(B)的群同态被K_0(π)提升的问题.从而得到,如果Φ为从K_0(D)到K_0(B)的正的群同态且Φ([1_D]_0)=[1_B]_0,则Φ可以被K_0(π)提升. 相似文献
728.
Extension results, expressed in terms of complete boundedness, leading to necessary and sufficient conditions for the solvability of power moment problems with unbounded operator data are given. As an application, necessary and sufficient conditions for the existence of selfadjoint and normal extensions for some classes of commuting tuples of unbounded linear operators are obtained. 相似文献
729.
Figen Öke 《Applied mathematics and computation》2011,218(3):956-958
Let v be a valuation of a field K, Gv its value group and kv its residue field. Let w be an extension of v to K(x1, … , xn). w is called a residual transcendental extension of v if kw/kv is a transcendental extension. In this study a residual transcendental extension w of v to K(x1, … , xn) such that transdegkw/kv = n is defined and some considerations related with this valuation are given. 相似文献
730.
Iskander Aliev 《Journal of Combinatorial Theory, Series A》2011,118(2):525-531
Given a primitive positive integer vector a, the Frobenius number F(a) is the largest integer that cannot be represented as a non-negative integral combination of the coordinates of a. We show that for large instances the order of magnitude of the expected Frobenius number is (up to a constant depending only on the dimension) given by its lower bound. 相似文献