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1.
As in [N], [LN] the Newton diagram is used in order to get information about the first terms of the Puiseux expansions of the eigenvalues () of the perturbed matrix pencilT(, )=A()+B(, ) in the neighbourhood of an unperturbed eigenvalue () ofA(). In fact sufficient conditions are given which assure that the orders of these first terms correspond to the partial multiplicities of the eigenvalue 0 ofA(). 相似文献
2.
Summary For each in some domainD in the complex plane, letF() be a linear, compact operator on a Banach spaceX and letF be holomorphic in . Assuming that there is a so thatI–F() is not one-to-one, we examine two local methods for approximating the nonlinear eigenvalue . In the Newton method the smallest eigenvalue of the operator pencil [I–F(),F()] is used as increment. We show that under suitable hypotheses the sequence of Newton iterates is locally, quadratically convergent. Second, suppose 0 is an eigenvalue of the operator pencil [I–F(),I] with algebraic multiplicitym. For fixed leth() denote the arithmetic mean of them eigenvalues of the pencil [I–F(),I] which are closest to 0. Thenh is holomorphic in a neighborhood of andh()=0. Under suitable hypotheses the classical Muller's method applied toh converges locally with order approximately 1.84. 相似文献
3.
B. T. Rumov 《Mathematical Notes》1976,19(4):376-382
This paper proves the existence of resolvable block designs with divisibility into groups GD(v; k, m; 1, 2) without repeated blocks and with arbitrary parameters such that 1 = k, (v–1)/(k–1) 2 vk–2 (and also 1 k/2, (v–1)/(2(k–1)) 2 vk–2 in case k is even) k 4 andp=1 (mod k–1), k < p for each prime divisor p of number v. As a corollary, the existence of a resolvable BIB-design (v, k, ) without repeated blocks is deduced with X = k (and also with = k/2 in case of even k) k
, where a is a natural number if k is a prime power and=1 if k is a composite number.Translated from Matematicheskie Zametki, Vol. 19, No. 4, pp. 623–634, April, 1976. 相似文献
4.
Bo Deng Gary H. Meisters Gaetano Zampieri 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1995,46(6):872-882
We consider Keller's functions, namely polynomial functionsf:C
n C
n with detf(x)=1 at allx C
n. Keller conjectured that they are all bijective and have polynomial inverses. The problem is still open.Without loss of generality assumef(0)=0 andf'(0)=I. We study the existence of certain mappingsh
, > 1, defined by power series in a ball with center at the origin, such thath(0)=I andh
(f(x))=h
(x). So eachh
conjugates f to its linear part I in a ball where it is injective.We conjecture that for Keller's functionsf of the homogeneous formf(x)=x +g(x),g(sx)=s
dg(x),g(x)n=0,xC
n,sC the conjugationh
for f is anentire function. 相似文献
5.
Giovanna Cerami 《Annali di Matematica Pura ed Applicata》1988,150(1):119-127
Summary In this paper a necessary and sufficient condition for the existence of negative eigenvalues for the problem-u – u=(x)¦u¦p–2u in u¦=0 is given. Here Rn is supposed a smooth bounded domain, 0 a bounded nonnegative function, (1, 2), 1 and 1 being the first and the second eigenvalue of - in with zero Dirichlet boundary data, p2 and, if n 3, p < 2n¦(n–2). Moreover in the linear case (p=2) a uniqueness result is proved.Work supported by G.N.A.F.A. and by M.P.I, of Italy Fondi 40% Equazioni Differenziali e Calcolo delle Variazioni and Fondi 60% Analisi matematica. 相似文献
6.
Kirsten Mackenzie-Fleming 《Designs, Codes and Cryptography》1998,13(2):159-164
This paper contains two main results: given a symmetric (v, k, ) design, D, and a resolvable design which has the parameters of a residual design of D, there exists a symmetric (dv + 1, v, k) design, where d = (v - k)/(k - ), and d is a prime power; given a symmetric (v, k, ) design, D, and a resolvable design with the parameters of a derived design of D, there exists a 2 - (ek + v, 2k, k) design, where e = k/,and e is a prime power. 相似文献
7.
Bruno Zwahlen 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1979,30(4):709-712
Summary For a non-linear boundary value problem with a positive and increasing non-linearity there exists a critical value* of the parameter, beyond which there are no solutions. We give a minimax characterization of*.
Zusammenfassung In der Randwertaufgabe –u(x)=f(x, u(x)), u(a)=u(b)=0, seif positiv und wachsend im zweiten Argument. Dann gibt es einen Wert*, so dass keine Lösung existiert für>*. In dieser Arbeit wird* durch ein Minimaxprinzip charakterisiert. Der Beweis beruht auf der Anwendung von Ober- und Unterlösungen und monotonen Iterationen.相似文献
8.
Let H be a real Hilbert space and let <..,.> denote the corresponding scalar product. Given a
function
that is bounded from below, we consider the following dynamical system:
where (x) corresponds to a quadratic approximation to a linear search technique in the direction –(x). The term (x) is connected intimately with the normal curvature radius (x) in the direction (x). The remarkable property of (SDC) lies in the fact that the gradient norm |(x(t))| decreases exponentially to zero when t+.When is a convex function which is nonsmooth or lacks strong convexity, we consider a parametric family {, >0} of smooth strongly convex approximations of and we couple this approximation scheme with the (SDC) system. More precisely, we are interested in the following dynamical system:
where (t, x) is a time-dependent function involving a curvature term. We find conditions on the approximating family and on () ensuring the asymptotic convergence of the solution trajectories x() toward a particular solution of the problem min {(x), xH}. Applications to barrier and penalty methods in linear programming and to viscosity methods are given. 相似文献
9.
T. I. Akhobadze 《Analysis Mathematica》1982,8(2):79-102
. , , –1<<0. .
The present work was written on the basis of two earlier works received byAnalysis Mathematica on January 16, 1979, and July 20, 1979. 相似文献
The present work was written on the basis of two earlier works received byAnalysis Mathematica on January 16, 1979, and July 20, 1979. 相似文献
10.
Suppose that A is an n × n nonnegative matrix whose eigenvalues are = (A), 2, ..., n. Fiedler and others have shown that \det( I -A) n - n, for all > with equality for any such if and only if A is the simple cycle matrix. Let a
i be the signed sum of the determinants of the principal submatrices of A of order i × i, i=1, ..., n - 1. We use similar techniques to Fiedler to show that Fiedler's inequality can be strengthened to:
for all . We use this inequality to derive the inequality that:
. In the spirit of a celebrated conjecture due to Boyle-Handelman, this inequality inspires us to conjecture the following inequality on the nonzero eigenvalues of A: If 1 = (A), 2,...,k
are (all) the nonzero eigenvalues of A, then
. We prove this conjecture for the case when the spectrum of A is real. 相似文献
11.
G. J. Cooper 《BIT Numerical Mathematics》1996,36(1):77-85
This article examines stability properties of some linear iterative schemes that have been proposed for the solution of the nonlinear algebraic equations arising in the use of implicit Runge-Kutta methods to solve a differential systemx =f(x). Each iteration step requires the solution of a set of linear equations, with constant matrixI –hJ, whereJ is the Jacobian off evaluated at some fixed point. It is shown that the stability properties of a Runge-Kutta method can be preserved only if is an eigenvalue of the coefficient matrixA. SupposeA has minimal polynomial (x – )
m
p(x),p() 0. Then stability can be preserved only if the order of the method is at mostm + 2 (at mostm + 1 except for one case).This work was partially supported by a grant from the Science and Engineering Research Council. 相似文献
12.
Osvaldo Marrero 《Aequationes Mathematicae》1977,16(3):195-220
This work is an attempt to give a complete survey of all known results about pseudo (v, k, )-designs. In doing this, the author hopes to bring more attention to his conjecture given in Section 6; an affirmative answer to this conjecture would settle completely the existence and construction problem for a pseudo (v, k, )-design in terms of the existence of an appropriate (v, k, )-design. 相似文献
13.
T. Ya. Kon'kova V. N. Kublanovskaya L. T. Savinova 《Journal of Mathematical Sciences》1980,13(2):230-240
This paper examines the solving of the eigenvalue problem for a matrix M () with a nonlinear occurrence of the spectral parameter. Two methods are suggested for replacing the equation dat M()=0 by a scalar equationf()=0. Here the functionf() is not written formally, but a rule for computingf() at a fixed point of the domain in which the desired roots lie is indicated. Müller's method is used to solve the equationf()=0. The eigenvalue found is refined by Newton's method based on the normalized expansion of matrix M(), and the linearly independent vectors corresponding to it are computed. An ALGOL program and test examples are presented.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 58, pp. 54–66, 1976. 相似文献
14.
We study the regularity of the minimizer u
for the functional F
(u,f)=|u|2 + |u–f{2 over all maps uH
1(, S
2). We prove that for some suitable functions f every minimizer u
is smooth in if 0 and for the same functions f, u
has singularities when is large enough.
Résumé On étudie la régularité des minimiseurs u du problème de minimisation minueH 1(,S2)(|u|2 + |u–f{2. On montre que pour certaines fonctions f, u est régulière lorsque 0 et pour les mêmes f, si est assez grand, alors u possède des singularités.相似文献
15.
Consider a functionL() defined on an interval of the real axis whose values are linear bounded selfadjoint operators in a Hilbert spaceH. A point 0 and a vector
0 H(
0 0) are called eigenvalue and eigenvector ofL() ifL() ifL(0)
0 = 0. Supposing that the functionL() can be represented as an absolutely convergent Fourier integral, the interval is sufficiently small and the derivative will be positive at some point, it has been proved that all the eigenvectors of the operator-functionL() corresponding to the eigenvalues from the interval form an unconditional basis in the subspace spanned by them. 相似文献
16.
Haim Brezis Luis A. Caffarelli Avner Friedman 《Annali di Matematica Pura ed Applicata》1980,123(1):219-246
Summary Consider the Dirichlet problem for an elliptic equation in a domain , with coefficients having discontinuity on a surface . Suppose divides into 1 2(2 the inner core), the thickness of 1 is of order of magnitude , and the modulus of ellipticity in 1 is of order magnitude 1. The asymptotic behavior of the solution is studied as 0, 1 0, provided lim (/1) exists. Other questions of this type are studied both for elliptic equations and for elliptic variational inequalities.The second author is partially supported by National Science Foundation Grant 7406375 A01. The third author is partially supported by National Science Foundation Grant MC575-21416 A01. 相似文献
17.
We consider a selfadjoint and smooth enough operator-valued functionL() on the segment [a, b]. LetL(a)0,L(b)0, and there exist two positive numbers and such that the inequality |(L()f, f)|< ([a, b] f=1) implies the inequality (L'()f, f)>. Then the functionL() admits a factorizationL()=M()(I-Z) whereM() is a continuous and invertible on [a, b] operator-valued function, and operatorZ is similar to a selfadjoint one. This result was obtained in the first part of the present paper [10] under a stronge conditionL()0 ( [a,b]). For analytic functionL() the result of this paper was obtained in [13]. 相似文献
18.
Let be a probability measure on n 2 × 2 stochastic matrices, n an arbitrary positive integer, and = (w) lim
n
n
, such that the support of consists of 2 × 2 stochastic matrices of rank one, and as such, can be regarded as a probability measure on [0, 1]. We present simple sufficient conditions for to be continuous singular w.r.t. the Lebesgue measure on [0, 1]. We also determine , given . 相似文献
19.
B. D. Sleeman E. M. E. Zayed 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1984,35(1):106-115
Summary The trace function
where {
m}
m=1
are the eigenvalues of the Laplacian is studied for a variety of domains. The dependence of(t) on the connectivity of a domain and the boundary conditions is analysed. Particular attention is given to annular domains.
Résumé Pour divers domaines, on étudie la fonction trace , où 1, 2, 3, sont les valeurs propres du laplacien. On analyse comment(t) dépend du domaine et des conditions aux limites. On considère notamment le cas de couronnes circulaires.相似文献
20.
Sharad Sane 《Designs, Codes and Cryptography》2001,23(3):291-296
A proof of the following conjecture of Jungnickel and Tonchev on quasi-multiple quasi-symmetric designs is given: Let D be a design whose parameter set (v,b,r,k,) equals (v,sv,sk,k, s) for some positive integer s and for some integers v,k, that satisfy (v-1) = k(k-1) (that is, these integers satisfy the parametric feasibility conditions for a symmetric (v,k,)-design). Further assume that D is a quasi-symmetric design, that is D has at most two block intersection numbers. If (k, (s-1)) = 1, then the only way D can be constructed is by taking multiple copies of a symmetric (v,k, )-design. 相似文献