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1.
In this paper, we prove that for an algebroid function w(z), the singular direction arg z =φ0 , satisfying that for arbitrary ε(0 < ε < π 2 ) and any given a ∈ C, lim r → + ∞ n(r,φ0-ε,φ0 +ε,w=a)/ log r = +∞ holds with at most 2v possible exceptional values of a, is the Nevanlinna direction of w(z).  相似文献   

2.
Inclines are the additively idempotent semirings in which products are less than or equal to either factor. In this paper, some necessary and sufficient conditions for a matrix over L to be invertible are given, where L is an incline with 0 and 1. Also it is proved that L is an integral incline if and only if GLn(L) = PLn (L) for any n (n 〉 2), in which GLn(L) is the group of all n × n invertible matrices over L and PLn(L) is the group of all n × n permutation matrices over L. These results should be regarded as the generalizations and developments of the previous results on the invertible matrices over a distributive lattice.  相似文献   

3.
We consider the properties on solutions of some q-difference equations of the form ∑ n j=0 aj(z)f(qj z)=an+1(z), where a0(z),..., an+1(z) are meromorphic functions, a0(z)an(z) ≠ 0 and q ∈ C such that 0 〈 |q| ≤ 1. We give estimates on the upper bound for the length of the gap in the power series of entire solutions of (*) when the coefficients a0(z),..., an+1(z) are polynomials and 0 〈 |q| 〈 1. For some special cases, we give estimates of growth of f(z). And we also show that the case 0 〈 |q| 〈 1 is different from the case |q|=1.  相似文献   

4.
The main purpose of this paper is to study the lower order and type of second order differential equation w"(z)-A(z)w=0,where A(z)is a polynomial.In the case of A(z)=a_dz~d,the authors prove that the lower order and the type of all non-trivial solutions w of w"(z)-A(z)w=0 are equal to(d+2)/2 and(2(|a_d|)~(1/2))/(d+2)respectively.In the case of A(z)=a_dz~d+a_(d-1)z~(d-1)+…a_1z+a_0,a_d0,a_(d-1)0,…,a_1≥0,a_0≥0,the authors prove that the lower order of all non-trivial solutions w of w"(z)-A(z)w=0 is(d+2)/2.  相似文献   

5.
In this paper,the zeros of solutions of periodic second order linear differential equation y + Ay = 0,where A(z) = B(e z ),B(ζ) = g(ζ) + p j=1 b ?j ζ ?j ,g(ζ) is a transcendental entire function of lower order no more than 1/2,and p is an odd positive integer,are studied.It is shown that every non-trivial solution of above equation satisfies the exponent of convergence of zeros equals to infinity.  相似文献   

6.
7.
Bang Yen  CHEN 《数学学报(英文版)》2009,25(12):1987-2022
It is well known that a totally geodesic Lagrangian surface in a Lorentzian complex space form M12(4ε) of constant holomorphic sectional curvature 4s is of constant curvature 6. A natural question is "Besides totally geodesic ones how many Lagrangian surfaces of constant curvature εin M12(46) are there?" In an earlier paper an answer to this question was obtained for the case e = 0 by Chen and Fastenakels. In this paper we provide the answer to this question for the case ε≠0. Our main result states that there exist thirty-five families of Lagrangian surfaces of curvature ε in M12(4ε) with ε ≠ 0. Conversely, every Lagrangian surface of curvature ε≠0 in M12(4ε) is locally congruent to one of the Lagrangian surfaces given by the thirty-five families.  相似文献   

8.
In this paper, we investigate the Hadamard factorization theorem of analytic functions in the finite disc DR = {z ∈ C : |z| = r R ∞}, where C is the whole complex plane. Examples are given to show that our results are sharp.  相似文献   

9.
In an anonymous secret sharing scheme the secret can be reconstructed without knowledge ofwhich participants hold which shares.In this paper some constructions of anonymous secret sharing schemeswith 2 thresholds by using combinatorial designs are given.Let v(t,w,q)denote the minimum size of the setof shares of a perfect anonymous(t,w)threshold secret sharing scheme with q secrets.In this paper we provethat v(t,w,q)=(q)if t and w are fixed and that the lower bound of the size of the set of shares in[4]is notoptimal under certain condition.  相似文献   

10.
Let Z be a topological space and mapping A2 :Z→B(H) with closed range R(A2 ) be continuous . Some necessary and sufficient conditions of the continuity of M-P inverses A z+ are given in [1], [2]. It is one of them that AZ+ is continuous if ana only if AZ+ is locallybounded. In this paper, we discuss the following problem: if limA n = A0 in B(H) and ||An+||is unbounded (i.e. the above necessary and sufficient condition fails), what h in H will make the equations: limAm+ h = A0+ h or w-limAn+ h= A 0+ h be true. For this purpose three theorems and an error estimation are given in this paper.  相似文献   

11.
D是由复平面z中一条Jordal闭曲线Γ围成的单连区域,z=0∈D.函数u(z)在D内调和且在Γ上u(q)∈L中α(0α1).基于复插值逼近理论证明了:存在唯一的调和插值多项式u_n~*(z),它与调和函数u(z)在Γ的摄动Fejer点{z_k~*}_0~(n-1)上有相同的值,在D上一致收敛于u(z),且收敛是稳定的.所得结果改进并推广了同类课题中已有的工作.  相似文献   

12.
设w(z)为单位圆盘U到约当区域Ω?C上的调和映照.给出w(z)具有Lipschitz性质的等价条件.进一步地,若Ω为有界凸区域,对其边界函数给出一个较弱的条件,使得w=P[f](z)为调和拟共形映照.  相似文献   

13.
Let $s_n(f,z):=\sum_{k=0}^{n}a_kz^k$ be the $n$th partial sum of $f(z)=\sum_{k=0}^{\infty{}}a_kz^k$. We show that $\RE s_n(f/z,z)>0$ holds for all $z\in\D,\ n\in\N$, and all starlike functions $f$ of order $\lambda$ iff $\lambda_0\leq\lambda<1$ where $\lambda_0=0.654222...$ is the unique solution $\lambda\in(\frac{1}{2},1)$ of the equation $\int_{0}^{3\pi/2}t^{1-2\lambda}\cos t \,dt=0$. Here $\D$ denotes the unit disk in the complex plane $\C$. This result is the best possible with respect to $\lambda_0$. In particular, it shows that for the Gegenbauer polynomials $C_{n}^{\mu}(x)$ we have $\sum_{k=0}^n C_{k}^{\mu}(x)\cos k \theta>0$ for all $n\in\N,\ x\in[-1,1]$, and $0<\mu\leq\mu_0:=1-\lambda_0=0.345778...$. This result complements an inequality of Brown, Wang, and Wilson (1993) and extends a result of Ruscheweyh and Salinas (2000).  相似文献   

14.
§1.IntroductionandMainResultsThispaperisanextensionofthework[8].Weconsidertheexistenceofinfinitelymanyhomoclinicorbitsforthef...  相似文献   

15.
研究了代数体函数w(z)的Borel方向和确定该代数体函数的复方程A_k(z)w~k+_(Ak-1)(z)w~_(k-1)+…+A_0(z)=0的系数函数A_k(z),A_(k-1)(z),…,A_0(z)的Borel方向之间的关系.  相似文献   

16.
Let β 〉 0 and Sβ := {z ∈ C : |Imz| 〈β} be a strip in the complex plane. For an integer r ≥ 0, let H∞^Г,β denote those real-valued functions f on R, which are analytic in Sβ and satisfy the restriction |f^(r)(z)| ≤ 1, z ∈ Sβ. For σ 〉 0, denote by Bσ the class of functions f which have spectra in (-2πσ, 2πσ). And let Bσ^⊥ be the class of functions f which have no spectrum in (-2πσ, 2πσ). We prove an inequality of Bohr type
‖f‖∞≤π/√λ∧σ^r∑k=0^∞(-1)^k(r+1)/(2k+1)^rsinh((2k+1)2σβ),f∈H∞^r,β∩B1/σ,
where λ∈(0,1),∧and ∧′are the complete elliptic integrals of the first kind for the moduli λ and λ′=√1- λ^2,respectively,and λ satisfies
4∧β/π∧′=1/σ.
The constant in the above inequality is exact.  相似文献   

17.
Let $T(\cdot)$ be an analytic $C_0$-semigroup of operators in a sector $S_{\theta}$, such that $||T(\cdot)||$ is bounded in each proper subsector $S_{\theta_0}$. Let $A$ be its generator, and let $D^{\infty}(A)$ be its set of $C^{\infty}$-vectors. It is observed that the (general) Cauchy integral formula implies the following extension of Theorem 5.3 in [1] and Theorem 1 in [4]: for each proper subsector $S_{\theta_0}$, there exist positive constants $M,\,\delta$ depending only on $\theta_0$, such that $(\delta^n/n!)||z^nA^nT(z)x||\leq M\,||x||$ for all $n\in\Bbb N,\, z\in S_{\theta_0}$, and $x\in D^{\infty}(A)$. It follows in particular that the vectors $T(z)x$ (with $z\in S_{\theta}$ and $x\in D^{\infty}(A)$) are analytic vectors for $A$ (hence $A$ has a dense set of analytic vectors).  相似文献   

18.
Let denote the linear space over spanned by . Define the (real) inner product , where V satisfies: (i) V is real analytic on ; (ii) ; and (iii) . Orthogonalisation of the (ordered) base with respect to yields the even degree and odd degree orthonormal Laurent polynomials , and . Define the even degree and odd degree monic orthogonal Laurent polynomials: and . Asymptotics in the double-scaling limit such that of (in the entire complex plane), , and (in the entire complex plane) are obtained by formulating the odd degree monic orthogonal Laurent polynomial problem as a matrix Riemann-Hilbert problem on , and then extracting the large-n behaviour by applying the non-linear steepest-descent method introduced in [1] and further developed in [2],[3].  相似文献   

19.
Let $S$ be a semigroup of words over an alphabet $A$. Let $\Omega(S)$ consist of those elements $w$ of $S$ for which every prefix and suffix of $w$ belongs to $S$. We show that $\Omega(S)$ is a free semigroup. Moreover, $S$ is called separative if also the complement $S^c = A^+\setminus S$ is a semigroup. There are uncountably many separative semigroups over $A$, if $A$ has at least two letters. We prove that if $S$ is separative, then every word $w \in A^+$ has a unique minimum factorization $w = z_1z_2 \cdots z_n$ with respect to $\Omega(S)$ and $\Omega(S^c)$, where $z_i \in \Omega(S) \cup \Omega(S^c)$ and $n$ is as small as possible.  相似文献   

20.
A closed subspace $M$ of the Hardy space $H^2(\mathbb{D}^2)$ over the bidisk is called submodule if it is invariant under multiplication by coordinate functions $z$ and $w.$ Whether every finitely generated submodule is Hilbert-Schmidt is an unsolved problem. This paper proves that every finitely generated submodule $M$ containing $θ(z)−\varphi(w)$ is Hilbert-Schmidt, where $θ(z),$ $\varphi(w)$ are two finite Blaschke products.  相似文献   

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