The rigidity of Clifford torusS^1 \left( {\sqrt {\frac{1}{n}} } \right) \times S^{n - 1} \left( {\sqrt {\frac{{n - 1}}{n}} } \right)

In this paper, we prove that ifM is ann-dimensional closed minimal hypersurface with two distinct principal curvatures of a unit sphereS ⁿ⁺¹ (1), thenS=n andM is a Clifford torus ifn≤S≤n+[2n ²(n+4)/3(n(n+4)+4)], whereS is the squared norm of the second fundamental form ofM.     

Unbounded solutions of the max-type difference equation x_{n + 1} = max\left\{ {\frac{{A_n }} {{X_n }},\frac{{B_n }} {{X_{n - 2} }}} \right\}

We investigate the boundedness nature of positive solutions of the difference equation $$ x_{n + 1} = max\left\{ {\frac{{A_n }} {{X_n }},\frac{{B_n }} {{X_{n - 2} }}} \right\},n = 0,1,..., $$ where {A _n } _n=0 ^∞ and {B _n } _n=0 ^∞ are periodic sequences of positive real numbers.     

Remarks on the differential equation\frac{{dy}}{{dx}} = \frac{{y(y + x + 2)}}{{x(2x - y)}}

Zusammenfassung Es wird eine Übersicht über den Verlauf der Integralkurven einer in der Grenzschichttheorie auftretenden Differentialgleichung gegeben. Die Lösungen wurden mittels eines Analogrechners berechnet.     

Central limit theorem: Covergence in the norm\left\| u \right\|\left( {\int\limits_{ - \infty }^\infty {u^2 \left( x \right)e^{\frac{{x^2 }}{2}} dx} } \right)^{{\raise0.7ex\hbox{

Sufficient conditions for convergence in the central limit theorem (for identically distributed random variables) with respect to the topology specified in the title are given. These conditions hold for the uniform distribution although there exist distributions with smooth densities concentrated on a bounded interval for which the convergence result does not hold.     

The estimate for mean values on prime numbers relative to \frac{4} {p} = \frac{1} {{n_1 }} + \frac{1} {{n_2 }} + \frac{1} {{n_3 }}

If n is a positive integer,let f （n） denote the number of positive integer solutions （n 1,n 2,n 3） of the Diophantine equation 4/n=1/n₁ + 1/n₂ + 1/n₃.For the prime number p,f （p） can be split into f 1 （p） + f 2 （p）,where f i （p） （i=1,2） counts those solutions with exactly i of denominators n 1,n 2,n 3 divisible by p.In this paper,we shall study the estimate for mean values ∑ p相似文献   

L'equazioney\frac{{dy}}{{dx}} + y + \left| x \right|^v sgnx=0, (1≥v≥0)sgnx=0, (1≥v≥0)

Sunto Come viene indicato nell'introduzione l'A, studia il comportamento di tutti gli integrali dell'equazione oggetto della presente memoria, nel piano reale, per v ∈[0, 1], metendo in luce l'esistenza di due integrali fondamentali. Memoria dedicata a Masuo Hukuhara e Mitio Nagumo     

Existence of multiple positive solutions for - \Delta u = \lambda u + u^{\frac{{N + 2}}{{N - 2}}} + \mu f\left( x \right)*

In this paper, we discuss the existence and nonexistence of solutions for the problem311-2 where Ω is a bounded smoothness domain inR ^N, γ ε R¹, μ>-0,f(x) is a given non-negative function. Some interesting resultus have been obtained. This work was completed in Institute of Math. Academia Sinica as a visiting scholar     

On the Evaluation of the Integral $$\int_0^{{\pi \mathord{\left/ {\vphantom {\pi 4}} \right. \kern-\nulldelimiterspace} 4}} {\ln \left( {\cos ^{{m \mathord{\left/ {\vphantom {m n}} \right. \kern-\nulldelimiterspace} n}} \theta \pm \sin ^{{m \mathord{\left/ {\vphantom {m n}} \right. \kern-\nulldelimiterspace} n}} \theta } \right)d\theta } $$

The integral $$\int_0^{{\pi \mathord{\left/ {\vphantom {\pi 4}} \right. \kern-\nulldelimiterspace} 4}} {\ln \left( {\cos ^{{m \mathord{\left/ {\vphantom {m n}} \right. \kern-\nulldelimiterspace} n}} \theta \pm \sin ^{{m \mathord{\left/ {\vphantom {m n}} \right. \kern-\nulldelimiterspace} n}} \theta } \right)d\theta } $$ where m and n are relatively prime positive integers, is evaluated exactly in terms of elementary functions and the Catalan constant G.     

ALTERNATING BAND CRANK-NICOLSON METHOD FOR δu／δt=δ^2u／δx^2＋δ^2u／δy^2

the Alternating Segment Crank-Nicolson scheme for one-dimensional diffusion equation has been developed in [1],and the Alternating Block Crank-Nicolson method for two-dimensional problem in [2].The methods have the advantages of parallel computing,stability and good accuracy.In this paper for the two-dimensional diffusion equation,the net region is divided into bands,a special kind of block.This method is called the alternating Band Crank-Nicolson method.     

$${\left( \frac{G^{\prime }}{G}\right)}$$-expansion method for the generalized Zakharov equations

In this paper, we modified the so-called generalized (G′/G)-expansion method to obtain new traveling wave solutions for nonlinear differential equations. The generalized Zakharov equations are chosen to illustrate the method in detail.     

Three explicit formulas for the Taylor coefficients of the function\left( {\frac{{1 - z}}{{1 - xz}}} \right)^\lambda

We give three explicit formulas for the Taylor coefficients of the function in the title. As an application we prove a conjecture ofSilverman andSilvia for the fourth Taylor coefficient of a class of univalent functions starlike with respect to a boundary point.