共查询到20条相似文献，搜索用时 15 毫秒
1.
Let X, Y be vector spaces. It is shown that if a mapping f ： X → Y satisfies f（（x＋y）/2＋z）＋f（（x-y）/2＋z=f（x）＋2f（z）,（0.1） f（（x＋y）/2＋z）-f（（x-y）/2＋z）f（y）,（0.2） or 2f（（x＋y）/2＋x）=f（x）＋f（y）＋2f（z）（0.3）for all x, y, z ∈ X, then the mapping f ： X →Y is Cauchy additive.
Furthermore, we prove the Cauchy-Rassias stability of the functional equations （0.1）, （0.2） and （0.3） in Banach spaces. The results are applied to investigate isomorphisms between unital Banach algebras. 相似文献
2.
The aim of this paper is to study the stability problem of the generalized sine functional equations as follows： g（x）f（y）=f（x＋y/2）^2-f（x-y/2）^2 f（x）g（y）=f（x＋y/2）^2-f（x-y/2）^2,g（x）g（y）=f（x＋y/2）^-f（x-y/2）^2 Namely, we have generalized the Hyers Ulam stability of the （pexiderized） sine functional equation. 相似文献
3.
In this paper, we establish the general solution and the generalized Hyers-Ulam-Rassias stability problem for a cubic Jensen-type functional equation,4f（（3x＋y）/4）＋4f（（x＋3y）/4）=6f（（x＋y）/2）＋f（x）＋f（y）,9f（（2x＋y/3）＋9f（（x＋2y）/3）=16f（（x＋y）/2＋f（x）＋f（y）in the spirit of D. H. Hyers, S. M. Ulam, Th. M. Rassias and P. Gaevruta. 相似文献
4.
The connection between the functional inequalities
|
$f\left( {\frac{{x + y}}
{2}} \right) \leqslant \frac{{f\left( x \right) + f\left( y \right)}}
{2} + \alpha _J \left( {x - y} \right), x,y \in D,$f\left( {\frac{{x + y}}
{2}} \right) \leqslant \frac{{f\left( x \right) + f\left( y \right)}}
{2} + \alpha _J \left( {x - y} \right), x,y \in D, 相似文献
5.
Let U(λ, μ) denote the class of all normalized analytic functions f in the unit disk | z| < 1 satisfying the condition
|
$
\frac{{f(z)}}
{z} \ne 0and\left| {f'(z)\left( {\frac{z}
{{f(z)}}} \right)^{\mu + 1} - 1} \right| < \lambda ,\left| z \right| < 1.
$
\frac{{f(z)}}
{z} \ne 0and\left| {f'(z)\left( {\frac{z}
{{f(z)}}} \right)^{\mu + 1} - 1} \right| < \lambda ,\left| z \right| < 1.
相似文献
6.
Let $
\mathbb{B}
$
\mathbb{B}
be the unit ball in ℂ
n
and let H($
\mathbb{B}
$
\mathbb{B}
) be the space of all holomorphic functions on $
\mathbb{B}
$
\mathbb{B}
. We introduce the following integral-type operator on H($
\mathbb{B}
$
\mathbb{B}
):
|
$
I_\phi ^g (f)(z) = \int\limits_0^1 {\operatorname{Re} f(\phi (tz))g(tz)\frac{{dt}}
{t}} ,z \in \mathbb{B},
$
I_\phi ^g (f)(z) = \int\limits_0^1 {\operatorname{Re} f(\phi (tz))g(tz)\frac{{dt}}
{t}} ,z \in \mathbb{B},
相似文献
7.
Some problems involving the classical Hardy function
|
$
Z\left( t \right) = \zeta \left( {\frac{1}
{2} + it} \right)\left( {\chi \left( {\frac{1}
{2} + it} \right)} \right)^{ - {1 \mathord{\left/
{\vphantom {1 2}} \right.
\kern-\nulldelimiterspace} 2}} , \zeta \left( s \right) = \chi \left( s \right) \zeta \left( {1 - s} \right)
$
Z\left( t \right) = \zeta \left( {\frac{1}
{2} + it} \right)\left( {\chi \left( {\frac{1}
{2} + it} \right)} \right)^{ - {1 \mathord{\left/
{\vphantom {1 2}} \right.
\kern-\nulldelimiterspace} 2}} , \zeta \left( s \right) = \chi \left( s \right) \zeta \left( {1 - s} \right)
相似文献
8.
Zeta-generalized-Euler-constant functions,
|
$
\gamma \left( s \right): = \sum\limits_{k = 1}^\infty {\left( {\frac{1}
{{k^s }} - \int_k^{k + 1} {\frac{{dx}}
{{x^s }}} } \right)}
$
\gamma \left( s \right): = \sum\limits_{k = 1}^\infty {\left( {\frac{1}
{{k^s }} - \int_k^{k + 1} {\frac{{dx}}
{{x^s }}} } \right)}
相似文献
9.
In the “lost notebook”, Ramanujan recorded infinite product expansions for
|
$\frac{1}
{{\sqrt r }} - \left( {\frac{{1 - \sqrt 5 }}
{2}} \right)\sqrt r and \frac{1}
{{\sqrt r }} - \left( {\frac{{1 + \sqrt 5 }}
{2}} \right)\sqrt r ,$\frac{1}
{{\sqrt r }} - \left( {\frac{{1 - \sqrt 5 }}
{2}} \right)\sqrt r and \frac{1}
{{\sqrt r }} - \left( {\frac{{1 + \sqrt 5 }}
{2}} \right)\sqrt r , 相似文献
10.
Let Θ be a bounded open set in ℝ
n
, n ⩾ 2. In a well-known paper Indiana Univ. Math. J., 20, 1077–1092 (1971) Moser found the smallest value of K such that
|
$
\sup \left\{ {\int_\Omega {\exp \left( {\left( {\frac{{\left| {f(x)} \right|}}
{K}} \right)^{{n \mathord{\left/
{\vphantom {n {(n - 1)}}} \right.
\kern-\nulldelimiterspace} {(n - 1)}}} } \right):f \in W_0^{1,n} (\Omega ),\left\| {\nabla f} \right\|_{L^n } \leqslant 1} } \right\} < \infty
$
\sup \left\{ {\int_\Omega {\exp \left( {\left( {\frac{{\left| {f(x)} \right|}}
{K}} \right)^{{n \mathord{\left/
{\vphantom {n {(n - 1)}}} \right.
\kern-\nulldelimiterspace} {(n - 1)}}} } \right):f \in W_0^{1,n} (\Omega ),\left\| {\nabla f} \right\|_{L^n } \leqslant 1} } \right\} < \infty
相似文献
11.
The Cauchy problem for the higher order equations in the mKdV hierarchy is investigated with data in the spaces $
\hat H_s^r \left( \mathbb{R} \right)
$
\hat H_s^r \left( \mathbb{R} \right)
defined by the norm
|
$
\left\| {v_0 } \right\|_{\hat H_s^r \left( \mathbb{R} \right)} : = \left\| {\left\langle \xi \right\rangle ^s \widehat{v_0 }} \right\|_{L_\xi ^{r'} } , \left\langle \xi \right\rangle = \left( {1 + \xi ^2 } \right)^{\frac{1}
{2}} , \frac{1}
{r} + \frac{1}
{{r'}} = 1
$
\left\| {v_0 } \right\|_{\hat H_s^r \left( \mathbb{R} \right)} : = \left\| {\left\langle \xi \right\rangle ^s \widehat{v_0 }} \right\|_{L_\xi ^{r'} } , \left\langle \xi \right\rangle = \left( {1 + \xi ^2 } \right)^{\frac{1}
{2}} , \frac{1}
{r} + \frac{1}
{{r'}} = 1
相似文献
12.
In this paper,the parameterized Marcinkiewicz integrals with variable kernels defined by μΩ^ρ（f）（x）=（∫0^∞│∫│1-y│≤t Ω（x,x-y）/│x-y│^n-p f（y）dy│^2dt/t1＋2p）^1/2 are investigated.It is proved that if Ω∈ L∞（R^n） × L^r（S^n-1）（r〉（n-n1p＇/n） is an odd function in the second variable y,then the operator μΩ^ρ is bounded from L^p（R^n） to L^p（R^n） for 1 〈 p ≤ max{（n＋1）/2,2}.It is also proved that,if Ω satisfies the L^1-Dini condition,then μΩ^ρ is of type（p,p） for 1 〈 p ≤ 2,of the weak type（1,1） and bounded from H1 to L1. 相似文献
13.
In this paper, we establish the generalized Hyers–Ulam–Rassias stability of C*-ternary ring homomorphisms associated to the Trif functional equation 相似文献
14.
We consider the extended Rayleigh problem of hydrodynamic stability dealing with the stability of inviscid homogeneous shear
flows in sea straits of arbitrary cross section. We prove a short wave stability result, namely, if k > 0 is the wave number of a normal mode then k > k
c (for some critical wave number k
c) implies the stability of the mode for a class of basic flows. Furthermore, if $
K(z) = \frac{{ - (U'_0 - T_0 U'_0 )}}
{{U_0 - U_{0s} }}
$
K(z) = \frac{{ - (U'_0 - T_0 U'_0 )}}
{{U_0 - U_{0s} }}
, where U
0 is the basic velocity, T
0 (a constant) the topography and prime denotes differentiation with respect to vertical coordinate z then we prove that a sufficient condition for the stability of basic flow is $
0 < K(z) \leqslant \left( {\frac{{\pi ^2 }}
{{D^2 }} + \frac{{T_0^2 }}
{4}} \right)
$
0 < K(z) \leqslant \left( {\frac{{\pi ^2 }}
{{D^2 }} + \frac{{T_0^2 }}
{4}} \right)
, where the flow domain is 0 ≤ z ≤ D. 相似文献
15.
In this paper, let Σ R2n be a symmetric compact convex hypersurface which is ( r, R )- pinched with R/r (5/3)1/2 . Then Σ carries at least two elliptic symmetric closed characteristics; moreover, Σ carries at least E [ n-1/2 ] + E [ n-1/3 ] non-hyperbolic symmetric closed characteristics. 相似文献
16.
Suppose that X is a complex Banach space with the norm ‖·‖ and n is a positive integer with dim X ⩾ n ⩾ 2. In this paper, we consider the generalized Roper-Suffridge extension operator $
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)
$
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)
on the domain $
\Omega _{p_1 ,p_2 , \ldots ,p_{n + 1} }
$
\Omega _{p_1 ,p_2 , \ldots ,p_{n + 1} }
defined by
|
$
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)(x) = {*{20}c}
{\sum\limits_{j = 1}^n {\left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)} ^{\beta _j } (f'(x_1^* (x)))^{\gamma _j } x_1^* (x)x_j } \\
{ + \left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)^{\beta _{n + 1} } (f'(x_1^* (x)))^{\gamma _{n + 1} } \left( {x - \sum\limits_{j = 1}^n {x_1^* (x)x_j } } \right)} \\
$
\Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)(x) = \begin{array}{*{20}c}
{\sum\limits_{j = 1}^n {\left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)} ^{\beta _j } (f'(x_1^* (x)))^{\gamma _j } x_1^* (x)x_j } \\
{ + \left( {\frac{{f(x_1^* (x))}}
{{x_1^* (x)}}} \right)^{\beta _{n + 1} } (f'(x_1^* (x)))^{\gamma _{n + 1} } \left( {x - \sum\limits_{j = 1}^n {x_1^* (x)x_j } } \right)} \\
\end{array}
相似文献
17.
In this paper, we give a characterization of tori S^1 （ √ nr＋2-n/nr）×S^n-1（√ n-2/nr） and S^m （ √n/m ） ×S^n-m （√n-m/n）. Our result extends the result due to Li （1996）on the condition that M is an n-dimensional complete hypersurface in Sn＋1 with two distinct principal curvatures. Keywords principal curvature, Clifford torus, Gauss equations 相似文献
18.
Realization of Boolean functions in the class of oriented contact circuits (OCCs) with certain restrictions on the weight,
number, and types of adjacent contacts is studied. Oriented contact circuits are considered in which, from an arbitrary vertex,
at most λ arcs issue and at most ν different Boolean variables are used in the marks of the issuing arcs. The weight of a
vertex of an OCC is defined as being equal to λ if one arc enters a vertex and equal to λ(1 + ω), where ω > 0, otherwise.
Then, as usual, the weight of an OCC is defined as the sum of the weights of its vertices; the weight of a Boolean function,
as the minimum weight of OCCs realizing it; and Shannon function W
λ, ν, ω( n), as the maximum weight of the Boolean function of n variables. For this Shannon function, the so-called high-accuracy bound
|
$
W_{\lambda ,v,\omega } (n) = \frac{\lambda }
{{\lambda - 1}}\frac{{2^n }}
{n}\left( {1 + \frac{{\frac{{2\lambda - v - 2}}
{{\lambda - 1}}\log n \pm O(1)}}
{n}} \right),
$
W_{\lambda ,v,\omega } (n) = \frac{\lambda }
{{\lambda - 1}}\frac{{2^n }}
{n}\left( {1 + \frac{{\frac{{2\lambda - v - 2}}
{{\lambda - 1}}\log n \pm O(1)}}
{n}} \right),
相似文献
19.
This paper, by using of windowed Fourier transform (WFT), gives a family of embedding operators Tn:L^2(R)→L^2(C,e^-|z|^2/2dzd-↑z/4πi), s.t. TnL^2(R) lontain in L^2(C,e^-|z|^2/2dzd-↑z/4πi) are reproducing subspaces (n=0, Bargmann Space); and gives a reproducing kernel and an orthonormal basis (ONB) of TnL^2(R), Furthermore, it shows the orthogonal spaces decomposition of L^2(C,e^-|z|^2/2dzd-↑z/4πi). Finally, by using the preceding results, it shows the eigenvalues and eigenfunctions of a class of localization operators associated with WFT, which extends the result of Daubechies in [1] and [6]. 相似文献
20.
In this paper we generalize the method used to prove the Prime Number Theorem to deal with finite fields, and prove the following
theorem:
|
$
\pi (x) = \frac{q}
{{q - 1}}\frac{x}
{{\log _q x}} + \frac{q}
{{(q - 1)^2 }}\frac{x}
{{\log _q^2 x}} + O\left( {\frac{x}
{{\log _q^3 x}}} \right),x = q^n \to \infty
$
\pi (x) = \frac{q}
{{q - 1}}\frac{x}
{{\log _q x}} + \frac{q}
{{(q - 1)^2 }}\frac{x}
{{\log _q^2 x}} + O\left( {\frac{x}
{{\log _q^3 x}}} \right),x = q^n \to \infty
相似文献
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