INITIAL COEFFICIENT ESTIMATES FOR SOME SUBCLASSES OF M-FOLD SYMMETRIC BI-UNIVALENT FUNCTIONS

In the present investigation,we consider two new general subclasses B_(Σm)(τ,λ;α)and B*_(Σm)(τ,λ;β) of Σ_m consisting of analytic and m-fold symmetric bi-univalent functions in the open unit disk U.For functions belonging to the two classes introduced here,we derive non-sharp estimates on the initial coefficients |a_(m+1)| and |a_(2m+1)|.Several connections to some of the earlier known results are also pointed out.     

New Subclasses of Biholomorphic Mappings and the Modified Roper-Suffridge Operator

The authors propose a new approach to construct subclasses of biholomorphic mappings with special geometric properties in several complex variables. The RoperSuffridge operator on the unit ball B~n in C~n is modified. By the analytical characteristics and the growth theorems of subclasses of spirallike mappings, it is proved that the modified Roper-Suffridge operator [Φ_(G,γ)(f)](z) preserves the properties of S_Ω~*(A, B), as well as strong and almost spirallikeness of type β and order α on B~n. Thus, the mappings in S_Ω~*(A, B), as well as strong and almost spirallike mappings, can be constructed through the corresponding functions in one complex variable. The conclusions follow some special cases and contain the elementary results.     

一类解析函数的Fekete-Szeg不等式(英文)

The Fekete-Szego inequality for a subclass H(α,λ,A,B) of the class H of normalized analytic functions is studied.For each f(z)=z+~∞∑_(n=2)αnz~n ∈ H(α,λ,A,B),the sharp upper bounds of |α_3-α_2~2|for any complex parameter u are obtained by using the fundamental inequalities of analytic functions and analytical techniques and the applications of the inequality of functions defined with Hadaniard product are proved.     

Regularity of discrete multisublinear fractional maximal functions

We investigate the regularity properties of discrete multisublinear fractional maximal operators,both in the centered and uncentered versions.We prove that these operators are bounded and continuous from?~1(Z~d)×?~1(Z~d)×···×?~1(Z~d)to BV(Z~d),where BV(Z~d)is the set of functions of bounded variation defined on Zd.Moreover,two pointwise estimates for the partial derivatives of discrete multisublinear fractional maximal functions are also given.As applications,we present the regularity properties for discrete fractional maximal operator,which are new even in the linear case.     

Singular Integrals with Bilinear Phases

We prove the boundedness from Lp（T2） to itself, 1 〈 p 〈∞, of highly oscillatory singular integrals Sf（x, y） presenting singularities of the kind of the double Hilbert transform on a non-rectangular domain of integration, roughly speaking, defined by ｜y′｜ 〉 ｜x′｜, and presenting phases λ（Ax ＋ By） with 0≤ A, B ≤ 1 and λ≥ 0. The norms of these oscillatory singular integrals are proved to be independent of all parameters A1 B and A involved. Our method extends to a more general family of phases. These results are relevant to problems of almost everywhere convergence of double Fourier and Walsh series.     

On new classes of strongly Janowski type functions of complex order

We investigate some new subclasses of analytic functions of Janowski type of complex order. We also study inclusion properties, distortion theorems, coefficient bounds and radius of convexity of the functions. Moreover, analytic properties of these classes under certain integral operator are also discussed. Our findings are more comprehensive than the existing results in the literature.     

满足Lipshitz条件的密度估计的最优收敛速度

Chen Guijing showed that for the onedimensional density functions satisfying λ-order Lipshitz conditions (λ∈(0,1]) the convergence rates of kernel estimates is of o ((]og n/n)~(λ/2λ+1) log log n), and he conjectured that λ/2λ+1 cannot be improved ([2]).In this paper we proved this conjecture being true.     

NECESSARY AND SUFFICIENT CONDITIONS OF EXISTENCE AND UNIQUENESS OF LIMIT CYCLES FOR A CLASS OF POLYNOMIAL SYSTEM

In this paper, we discuss the limit cycles of the systemdx/dt=y·[1+(A(x)]oy/dt=(-x+δy+α_1x~2+α_2xy+α_5x~2y)[1+B(x)] (1)where A(x)=sum form i=1 to n(a_ix~), B(x)=sum form j=1 to m(β_jx~j) and 1+B(x)>0. We prove that (1) possesses at most one limit cycle and give out the necessary and sufficient conditions of existence and uniqueness of limit cycles.     

On three differential equations associated with Chebyshev polynomials of degrees 3, 4 and 6

We shall study the differential equation y'~2= T_n(y)-(1-2μ~2);where μ~2 is a constant, T_n(x) are the Chebyshev polynomials with n = 3, 4, 6.The solutions of the differential equations will be expressed explicitly in terms of the Weierstrass elliptic function which can be used to construct theories of elliptic functions based on _2F_1(1/4, 3/4; 1; z),_2F_1(1/3, 2/3; 1; z), _2F_1(1/6, 5/6; 1; z) and provide a unified approach to a set of identities of Ramanujan involving these hypergeometric functions.     

SUBCLASSES OF BIHOLOMORPHIC MAPPINGS UNDER THE EXTENSION OPERATORS

In this article, we mainly study the invariance of some biholomorphic mappings with special geometric characteristics under the extension operators. First we generalize the Roper-Suffridge extension operators on Bergman-Hartogs domains. Then, by the geometric characteristics of subclasses of biholomorphic mappings, we conclude that the modified Roper-Suff ridge operators preserve the properties of S_Ω~*(β,A, B), parabolic and spirallike mappings of type β and order p, strong and almost spirallike mappings of type 0 and orderα as well as almost starlike mappings of complex order λ on Ω_(p1,…,ps,q)~(B~n) under different conditions, respectively. The conclusions provide new approaches to construct these biholomorphic mappings in several complex variables.     

由广义微分算子定义的某些解析函数类的优化性质

本文首先引入了由广义微分算子定义的某些$p$叶解析函数新子类$S_{p,q,\lambda}^{m,j,l}[A,B;\gamma]$ 和 $H_{p,q,\lambda}^{m,j,l}(\alpha,\beta)$, 然后研究了该子类的优化性质, 所得结果推广了某些已知结论.     

卷入Hohlov 算子的双单值函数某些子类的Fekete-Szeg\"o泛函问题

In the paper the new subclasses■and■of the function class∑of bi-univalent functions involving the Hohlov operator are introduced and investigated.Then,the corresponding Fekete-Szeg functional inequalities as well as the bound estimates of the coefficients a2 and a3 are obtained.Furthermore,several consequences and connections to some of the earlier known results also are given.     

The Starlikeness of Analytic Functions of Koebe Type with Complex Order

For α 0, λ 0 and β,η∈R, we consider the M(α,λ)_b of normalized analyticα—λ convex functions defined in the open unit disc U. In this paper we investigate the class M(α, λ,β,η)_b,with f_b := z/(1-z~n)~b being Koebe type. By making use of Jack's Lemma as well as several differential and other inequalities, the authors derive sufficient conditions for starlikeness of the class M(α, λ, β, η)_b of n-fold symmetric analytic functions of Koebe type. Relevant connections of the results presented here with those given in earlier works are also indicated.     

Janowski星形和凸函数族相关的非线性积分算子性质

In this paper, we consider a general nonlinear integral operator H_(αi),β_i(f_1,..., f_n;g_1,..., g_n)(z). Some results including coefficient problems, univalency condition and radius of convexity for this integral operator are given. Furthermore, we discuss the mapping properties between H_(αi),β_i(f_1,..., f_n; g_1,..., g_n)(z) and subclasses of analytic functions with bounded boundary rotation. The same subjects for some corresponding classes are shown upon specializing the parameters in our main results.     

Salagean算子定义的双单叶函数子类的系数估计

In this paper, a new subclass N_Σ~(h,p)(m, λ, μ) of analytic and bi-univalent functions in the open unit disk U is defined by salagean operator. We obtain coefficients bounds |a_2| and |a_3| for functions of the class. Moreover, we verify Brannan and Clunie's conjecture |a_2| ≤2~(1/2)for some of our classes. The results in this paper extend many results recently researched by many authors.     

Boundary Values of Generalized Harmonic Functions Associated with the Rank-One Dunkl Operator

We consider the local boundary values of generalized harmonic functions associated with the rank-one Dunkl operator $D$ in the upper half-plane $R^{2}_+=R\times(0,\infty)$, where $$(Df)(x)=f'(x)+(\lambda/x)[f(x)-f(-x)]$$ for given $\lambda\ge0$. A $C^2$ function $u$ in $R^{2}_+$ is said to be $\lambda$-harmonic if $(D_x^2+\partial_{y}^2)u=0$. For a $\lambda$-harmonic function $u$ in $R^{2}_+$ and for a subset $E$ of $\partial R^{2}_+=R$ symmetric about $y$-axis, we prove that the following three assertions are equivalent: (i) $u$ has a finite non-tangential limit at $(x,0)$ for a.e. $x\in E$; (ii) $u$ is non-tangentially bounded for a.e. $x\in E$; (iii) $(Su)(x)<\infty$ for a.e. $x\in E$, where $S$ is a Lusin-type area integral associated with the Dunkl operator $D$.     

On the Univalence of an Integral on Subclasses of Meromorphic Functions

We study the integral operator $P_\lambda |f|(\zeta ) = \int {_{\zeta _0 }^\zeta } \left( {f\prime \left( t \right)} \right)^\lambda dt,{\text{ }}|\zeta |{\text{ }} > 1$ , acting on the class ∑ of functions meromorphic and univalent in the exterior of the unit disk. We refine the ranges of the parameter λ for which the operator preserves univalence either on ∑ or on its subclasses consisting of convex functions. As a consequence, a two-sided estimate is deduced for the separating constant in the sufficient condition for the univalent solvability of exterior inverse boundary-value problems.     

New Sobolev-Weinstein Spaces and Applications

In this paper, we consider the generalized Weinstein operator $\Delta_{W}^{d,\alpha,n}$, we introduce new Sobolev-Weinstein spaces denoted $\mathscr H_{\alpha,d,n}^{s}(\mathbb{R}_{+}^{d+1}),$ $s\in\mathbb{R},$ associated with the generalized Weinstein operator and we investigate their properties. Next, as application, we study the extremal functions on the spaces $\mathscr H_{\alpha,d,n}^{s}(\mathbb{R}_{+}^{d+1})$ using the theory of reproducing kernels.     

由$q$-积分算子定义的某些亚纯函数类的Fekete-Szeg\"{o}问题

本文首先引入满足如下条件$$-\frac{qzD_{q}f(z)}{f(z)}\prec \varphi (z)$$和$$\frac{-(1-\frac{\alpha }{q})qzD_{q}f(z)+\alpha qzD_{q}[zD_{q}f(z)]}{(1-\frac{\alpha}{q})f(z)-\alpha zD_{q}f(z)}\prec \varphi (z)~(\alpha \in\mathbb{C}\backslash (0,1],\ 0相似文献   

单位方体上沿曲面的振荡积分在Sobolev空间上的有界性

研究了欧氏空间R~2中单位方体Q~2=[0,1]~2上沿曲面(t,s,γ(t,s))的振荡奇异积分算子T_(α,β)f(u,v,x)=∫_(Q~2)f(u-t,v-s,x-γ(t,s))e~(it~(-β_1)s~(-β_2))t~(-1-α_1)s~(-1-α_2)dtds从Sobolev空间L_τ~p(R~(2+n))到L~p(R~(2+n))中的有界性,其中x∈R~n,(u,v)∈R~2,(t,s,γ(t,s))=(t,s,t~(P_1)s~(q_1),t~(p_2)s~(q_2),…,t~(p_n)s~(q_n))为R~(2+n)上一个曲面,且β_1α_1≥0,β_2α_20.这些结果推广和改进了R~3上的某些已知的结果.作为应用,得到了乘积空间上粗糖核奇异积分算子的Sobolev有界性.