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1.
Let and . We are interested in the lower bounds of the integral:
where h > 0 and . Using the lower bounds for these integrals we obtain in particular for the so-called Fejér operator of the following asymptotic expression
which essentially improves the results concerning the approximation behavior of this operator. Received: 10 January 2006  相似文献   

2.
Ibαf ( x) =∫R ∏mj=1( bj( x) - bj( y) ) 1| x - y| n-αf ( y) dyare considered.The following priori estimates are proved.For 1 01Φ1t| {y∈Rn:| Ibαf( y) | >t}| 1q ≤csupt>01Φ1t| {y∈Rn:ML( log L) 1r ,α(‖b‖f ) ( y) >t}| 1q,where‖b‖=∏mj=1‖bj‖Oscexp Lrj,Φ( t) =t( 1 + log+t) 1r,1r =1r1+ ...+ 1rm,ML(…  相似文献   

3.
By coincidence degree, the existence of solution to the boundary value problem of a generalized Liénard equation
(1)
is proved, where are all constants, . An example is given as an application. Supported by NNSF of China (19831030).  相似文献   

4.
FINITETRAVELINGWAVESFORAREACTION┐DIFFUSIONSYSTEMWITHN(3)COMPONENTSWANGSHU,WENSHIHLIANGANDYEQIXIAOAbstract.Inthispaper,theex...  相似文献   

5.
§ 1  IntroductionIn[1 ] ,Karakostas and Tsamatos studied the existence of positive solutions for two-pointboundary value problemx″+ sign( 1 -c) q( t) f( x,x′) x′=0 ,( 1 .1 )x( 0 ) =0 ,x′( 1 ) =cx′( 0 ) ,( 1 .2 )where c∈ ( 0 ,1 )∪ ( 1 ,∞ ) .By using indices ofconvergence ofthe nonlinearity at0 and +∞and fixed point theorem in cones,they provided a priori upper and lower bounds for theslope of the solutions.The“c∈ ( 0 ,1 ) part”of their results has been extended to the fol-lowing …  相似文献   

6.
§ 1  IntroductionRecently,certain three-point boundary value problems for nonlinear ordinarydifferential equations have been studied by many authors[1— 6] .However,few papers havebeen published on the same problems for nonlinear functional differential equations.In thispaper,we are concerned with the following second order differential equation with anadvanced argumentu″(t) +λa(t) f(u(h(t) ) ) =0 ,t∈ (0 ,1 ) (1 .1 )with the three-point boundary conditionsu(0 ) =0 ,αu(η) =u(1 ) ,(1 .2 )…  相似文献   

7.
Let be a sequence of Borel measurable functions satisfying, for a function the inequalities
and suppose
Then there exists a sequence of increasing homeomorphisms converging to a homeomorphism weakly in and locally uniformly, such that
Dedicated to the memory of Jean Leray  相似文献   

8.
§ 1 IntroductionConsiderthenonautonomousdelaylogisticdifferenceequationΔyn =pnyn( 1 - yτ(n) )  ,n =0 ,1 ,2 ,...,( 1 1 )wherepn ∞n =0 isasequenceofpositiverealnumbers ,τ(n) ∞n =0 isanondecreasingsequenceofintegers,τ(n) <nandlimn→∞τ(n) =∞ ,Δyn=yn +1- yn.Motivatedbyplausibleapplications…  相似文献   

9.
Starting with an integral representation for the class of continuously differentiable solutions of the system
where is the complex Clifford algebra constructed over are some suitable Clifford vectors and their corresponding Dirac operators, we define the isotonic Cauchy transform and establish the Sokhotski-Plemelj formulae. Some consequences of this result are also derived.  相似文献   

10.
Let {X, X n;n≥1} be a strictly stationary sequence of ρ-mixing random variables with mean zero and finite variance. Set . Suppose lim n→∞ and , where d=2, if −1<b<0 and d>2(b+1), if b≥0. It is proved that, for any b>−1,
, where Γ(•) is a Gamma function. Research supported by the National Natural Science Foundation of China (10071072).  相似文献   

11.
We show that if μ is a finite Borel measure on the complex plane such that
for μ-a.e. , then μ must be the addition of some point masses, plus some measure absolutely continuous with respect to arc length on countably many rectifiable curves, plus another measure with zero linear density. We also prove that the same conclusion holds if instead of the condition μ-a.e. one assumes as -a.e. Partially supported by grants MTM2004-00519 and Acción Integrada HF2004-0208 (Spain), and 2001-SGR-00431 (Generalitat de Catalunya). Received: July 2005 Accepted: October 2005  相似文献   

12.
This paper discusses the oscillation of solutions for systems of nonlinear neutral type parabolic partial fuctional differential equations of the form  相似文献   

13.
Let Z/(pe) be the integer residue ring modulo pe with p an odd prime and integer e ≥ 3. For a sequence (a) over Z/(pe), there is a unique p-adic decomposition (a) = (a)0 (a)1·p … (a)e-1 ·pe-1, where each (a)i can be regarded as a sequence over Z/(p), 0 ≤ i ≤ e - 1. Let f(x) be a primitive polynomial over Z/(pe) and G' (f(x), pe) the set of all primitive sequences generated by f(x) over Z/(pe). For μ(x) ∈ Z/(p)[x] with deg(μ(x)) ≥ 2 and gcd(1 deg(μ(x)),p- 1) = 1,set ψe-1 (x0, x1,…, xe-1) = xe-1·[ μ(xe-2) ηe-3 (x0, x1,…, xe-3)] ηe-2 (x0, x1,…, xe-2),which is a function of e variables over Z/(p). Then the compressing map ψe-1: G'(f(x),pe) → (Z/(p))∞,(a) (→)ψe-1((a)0, (a)1,… ,(a)e-1) is injective. That is, for (a), (b) ∈ G' (f(x), pe), (a) = (b) if and only if ψe - 1 ((a)0, (a)1,… , (a)e - 1) =ψe - 1 ((b)0,(b)1,… ,(b)e-1). As for the case of e = 2, similar result is also given. Furthermore, if functions ψe-1 and ψe-1 over Z/(p) are both of the above form and satisfy ψe-1((a)0,(a)1,… ,(a)e-1) = ψe-1((b)0,(b)1,… ,(b)e-1) for (a),(b) ∈ G'(f(x),pe), the relations between (a) and (b), ψe-1 and ψe-1 are discussed.  相似文献   

14.
Let Δ(x) denote the error term in the Dirichlet divisor problem, and E(T) the error term in the asymptotic formula for the mean square of . If E *(t)=E(t)-2πΔ*(t/2π) with , then we obtain
and
It is also shown how bounds for moments of | E *(t)| lead to bounds for moments of .  相似文献   

15.
A SIMPLIFIED BRAUER'S THEOREM ON MATRIX EIGENVALUES   总被引:1,自引:0,他引:1  
Let A=(a ij)∈C n×n and . Suppose that for each row of A there is at least one nonzero off-diagonal entry. It is proved that all eigenvalues of A are contained in . The result reduces the number of ovals in original Brauer’s theorem in many cases. Eigenvalues (and associated eigenvectors) that locate in the boundary of are discussed. The project is supported in part by Natural Science Foundation of Guangdong.  相似文献   

16.
In the paper, we study the sufficient conditions for the lower-order coefficient of the parabolic equation
under which its solution satisfying the initial condition
stabilizes to zero, i.e., there exists the limit
uniform in x from every compact set K in ℝN for any function u 0(x) belonging to a certain uniqueness class of the problem considered and growing not rapidly than with a > 0 and b < 0 at infinity. __________ Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 12, No. 4, pp. 79–97, 2006.  相似文献   

17.
Let be a C*-algebra and X a Hilbert C* -module. If is a projection, let be the p-sphere of X. For φ a state of with support p in and consider the modular vector state φx of given by The spheres provide fibrations
and
These fibrations enable us to examine the homotopy type of the sets of modular vector states, and relate it to the homotopy type of unitary groups and spaces of projections. We regard modular vector states as generalizations of pure states to the context of Hilbert C*-modules, and the above fibrations as generalizations of the projective fibration of a Hilbert space.  相似文献   

18.
Let u(x) xR q be a symmetric nonnegative definite function which is bounded outside of all neighborhoods of zero but which may have u(0)=. Let p x, (·) be the density of an R q valued canonical normal random variable with mean x and variance and let {G x, ; (x, )R q ×[0,1 ]} be the mean zero Gaussian process with covariance
A finite positive measure on R q is said to be in with respect to u, if
When , a multiple Wick product chaos is defined to be the limit in L 2, as 0, of
where
,
denotes the Wick product of the m j normal random variables .Consider also the associated decoupled chaos processes , defined as the limit in L 2, as 0, of
where are independent copies of G x,.Define
Note that a neighborhood of the diagonals of in is excluded, except those points on the diagonal which originate in the same Wick product in (i). Set
One of the main results of this paper is: Theorem A. If is continuous on (R q ) r for all then is continuous on .When u satisfies some regularity conditions simple sufficient conditions are obtained for the continuity of on (R q ) r . Also several variants of (i) are considered and related to different types of decoupled processes. These results have applications in the study of intersections of Lévy process and continuous additive functionals of several Lévy processes.  相似文献   

19.
Let E be a non empty set, let P : = E × E, := {x × E|xE}, := {E × x|xE}, and := {C ∈ 2 P |∀X ∈ : |CX| = 1} and let . Then the quadruple resp. is called chain structure resp. maximal chain structure. We consider the maximal chain structure as an envelope of the chain structure . Particular chain structures are webs, 2-structures, (coordinatized) affine planes, hyperbola structures or Minkowski planes. Here we study in detail the groups of automorphisms , , , related to a maximal chain structure . The set of all chains can be turned in a group such that the subgroup of generated by the left-, by the right-translations and by ι the inverse map of is isomorphic to (cf. (2.14)).  相似文献   

20.
We solve the Dirichlet problem for line integrals of holomorphic functions in the unit ball For a function u which is lower semi-continuous on we give necessary and sufficient conditions in order that there exists a holomorphic function f ∈ such that
.  相似文献   

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