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1.
Let Γ≡(Γ, +,·) be the commutative ring of formal power series with real or complex coefficients, in which the ordinary addition and Cauchy multiplication are defined.Forφ,ψ∈Γ the composition φ(ψ(t) just means a formal substitution of u=ψ(t) into φ(u) in which the operations+and·can be performed indefinitely.We have the following  相似文献   

2.
In this paper, we give the following dominated theorem: Let φ(g) ∈ L1(G//K),φε(t)=ε> 0, and the least radical decreasing dominatedfunction φ(t) = sup |φ(y)| ∈L1(G//K). If shtφ(t) is monotonically decreasingon (0, ∞), then for any f∈L1loc(G//K) , the following inequality holds:sup |φε * f(x)| ≤ Cmf(x),where mf(x) is the Hardy-Littlewood maximal function of f, and C = ||φ||1.An application of this dominated theorem is also given.  相似文献   

3.
Here announced is an extension of the basic result presented in my fomernote (cf. The Fibonacci Quarterly,4 (1987),346-351). Denote by Г the ring of formal power series. Two elements φ and ψ are calledreciprocal elements if φ (ψ(t))=t With φ(0)=ψ(0)=0. Definition 1 A sequence of polynomials {P_n(t)} is said to be normal ifdeg p_n(t)=n, p_0(t)=1 and p_n(0)=0, (n1).  相似文献   

4.
Let(M, g(t)) be a compact Riemannian manifold and the metric g(t) evolve by the Ricci flow. We derive the evolution equation for the eigenvalues of geometric operator-△φ+ c R under the Ricci flow and the normalized Ricci flow, where △φis the Witten-Laplacian operator, φ∈ C∞(M), and R is the scalar curvature with respect to the metric g(t). As an application, we prove that the eigenvalues of the geometric operator are nondecreasing along the Ricci flow coupled to a heat equation for manifold M with some Ricci curvature condition when c 14.  相似文献   

5.
Let B(H) be the C*-algebra of all bounded linear operators on a complex Hilbert space H. It is proved that an additive surjective map φ on B(H) preserving the star partial order in both directions if and only if one of the following assertions holds.(1) There exist a nonzero complex number α and two unitary operators U and V on H such that φ(X) = αUXV or φ(X) = αUX*V for all X ∈ B(H).(2)There exist a nonzero α and two anti-unitary operators U and V on H such thatφ(X) = αUXV or φ(X) = αUX*V for all X ∈ B(H).  相似文献   

6.
Let σ(n) denote the set of partitions of n, usually denoted by 1~(k_1)2~(k_2)…n~(k_n) with k_1 2k_2 …nk_n. Let φ_i (t) (i=1,…, r) be power series in t (over comp lex field C) with positive radii of convergence and φ_i(0)=1.For every let the power-type generating function  相似文献   

7.
Let the time series {X(t),t=1,2,…}satisfy φ(B)(1-B)~dX(t)=θ(B)e(t),where B is a backward shift operator,defined by BX(t)=X(t-1),and φ(z)=1+φz+…+φ_pz~p,θ(z)=1+θ_1z+…+θ_qz~q%,and all the roots of φ(z)lie outside the unit circle;{e(t)}is a sequence of iid random variables with mean zero and E|e(t)|~(4+r)<∞(r>0).In this paper,the limit properties of S_n=sum from t=1 X(t)~2/t~(2d)log n,where the integer d≥1,have been considered.  相似文献   

8.
Let(Ai,φi,i+1) be a generalized indue Live system of a sequeiiee (Ai) of unital separable C^*-algebras,with A =limi→∞(Ai,φi,i+1). Set φj,i=φi-1,i^0…0φj+1,j+2^0 φj,j+1 for all i>j. We prove that if φj,i are order zero completely positive contractions for all j and i>j, And L:=inf{λ|λ∈σ(φj,i(1Aj)) for all j uud i>j}>0, where σ(φj,i(1Aj)) is the speetrum of φj,i(1Aj),than limi→∞(Cu(Ai),Cu((φi,i+1))=Cu(A), where Cu(A) is a stable version of the Cuntz semigroup of C^*-algebra A. Let (An,φm,n) be a generalized inductive syfitem of C^*-algahrafl, with the ipmkn order zero completely positive contractions. We also prove that if the decomposition rank (nuclear dimension) of ,4n is no more t han some integer k for each n, then the decompostition rank (nuclear dimension) of A is also no more than k.  相似文献   

9.
In this paper, we study the existence of nodal solutions for the following problem:-(φ_p(x′))′= α(t)φ_p(x~+) + β(t)φ_p(x~-) + ra(t)f(x), 0 t 1,x(0) = x(1) = 0,where φ_p(s) = |s|~(p-2)s, a ∈ C([0, 1],(0, ∞)), x~+= max{x, 0}, x~-=- min{x, 0}, α(t), β(t) ∈C[0, 1]; f ∈ C(R, R), sf(s) 0 for s ≠ 0, and f_0, f_∞∈(0, ∞), where f_0 = lim_|s|→0f(s)/φ_p(s), f_∞ = lim|s|→+∞f(s)/φ_p(s).We use bifurcation techniques and the approximation of connected components to prove our main results.  相似文献   

10.
Let Un be the unit polydisc of Cn and φ= (φ1,...,φn? a holomorphic self-map of Un. Let 0≤α< 1. This paper shows that the composition operator Cφ, is bounded on the Lipschitz space Lipa(Un) if and only if there exists M > 0 such thatfor z∈Un. Moreover Cφ is compact on Lipa(Un) if and only if Cφ is bounded on Lipa(Un) and for every ε > 0, there exists a δ > 0 such that whenever dist(φ(z),σUn) <δ  相似文献   

11.
Let C be the Cantor triadic set and let Cα=C+α={β+α: β∈C} for -1≤α≤ 1. Let Hp={α∈C: dim H(Cα∩C)=dim B(C α∩C)=(1-p)log 2/log 3}, 0< p< 1. The authors give the dimensions of C α∩C and Hp. In additionthe characteristic of Hp is described by means of some measure μ supported on C.  相似文献   

12.
Let λ(τ)be the elliptic function.We define the function t∶(0,∞);→(0,∞) byλ(1 it(α))=-α.The functiorl t(α)is a decreasing functiorl of a with t(1)= 1.In the following we need the function g(a)=ae~(πt).Let S denote the class of functions which are analytic in the unit disc D and omit 0 and 1.Schottky's theorem asserts the existence of a function K(α,γ)sueh that  相似文献   

13.
In this note, some conditions of composition operators on Dτspaces to be bounded are given by means of Carleson measures and pointwisemultipliers, for some ranges of τ. The authors prove that (i) Let 1<τ n+2 and 2k<τ 2k+1 (or 2k-1<τ 2k) for somepositive integer k. Suppose φ=(φ1,...,φn) be aunivalent mapping from B into itself, denote dμj(l)(z)=R(l)φj(z)2(k-l+2)(1-|z|2)2k-τ+1 dν(z) for l=1,2,...,k+1. If μj(l)φ-1 are (τ-2k+2l-4)-Carleson measures for all l, then the composition operator Cφon Dτis bounded; (ii) Let 1<τ n+2, φ=(φ1,...,φn)be univalent and the Fr echet derivativeof φ-1 be bounded onφ(B). If Rφj∈M(Dτ-2) forall j, then the composition operator Cφ on Dτis bounded; (iii) Let τ>n+2 and φ as in (ii).If φj∈Dτ for all j, then the compositionoperator Cφ on Dτ is bounded.  相似文献   

14.
Let A be an expansive dilation on R~n and φ:R~n× [0,∞)→[0,∞) an anisotropic Musielak–Orlicz function.Let H_A~φ(R~n) be the anisotropic Hardy space of Musielak–Orlicz type defined via the grand maximal function.In this article,the authors establish its molecular characterization via the atomic characterization of H_A~φ(R~n).The molecules introduced in this article have the vanishing moments up to order s and the range of s in the isotropic case(namely,A:=2I_(n×n)) coincides with the range of well-known classical molecules and,moreover,even for the isotropic Hardy space H~p(R~n)with p∈(0,1](in this case,A:=2I_(n×n),φ(x,t) :=t~p for all x∈R~n and t∈[0,∞)),this molecular characterization is also new.As an application,the authors obtain the boundedness of anisotropic Calderón–Zygmund operators from H_A~φ(R~n) to L~φ(R~n) or from H_A~φ(R~n) to itself.  相似文献   

15.
Let φ1, φ2 be nonnegative nondecreasing functions, and φl be concave. The authors prove the equivalence of the following two conditions:(i) Eφ1 (Mf) ≤ cEφ2(Zo+A∞) for every nonnegative submartingale f = (fn)n≥0 with it's Doob's Decomposition: f = Z + A, where Z is a martingale in L1 and A is a nonnegative incrasing and predictable process.(ii) There exists positive constants c, to such that ft∞φ1(s)/s2 ds ≤ c φ2(t)/t, t > to.When φ1 = φ2 the condition (ii) above is equivalent to the classical condition -Pφ<1. As a consequence, for a concave function φ, -Pφ< 1 if and only if Eφ1 (Mf) ≤ cEφ2 (Z0 + A∞)for every nonnegative submartingale f.  相似文献   

16.
Let [a,b] be a compact set containing at least n+1 points,C the set ofall continuous real valued functions defined on with uniform norm If φ_n=span{φ_1,…,φ_n),φ_i∈C([a,b])and φ_1,…,φ_n is an extended Chebyshev system of or-der,r(1≤r≤n),then we call K={q∈φ_n:l(x)≤q(x)≤u(x),x∈[a,b]} the set ofgeneralized polynomials having restricted ranges,where l and u are extended real  相似文献   

17.
Let Γ?R~2 be a regular anisotropic fractal. We discuss the problem of the negative spectrum for the Schr?dinger operators associated with the formal expression H_β=id-?+βtr_b~Γ,β∈R,acting in the anisotropic Sobolev space W_2~(1,α)(R~2), where ? is the Dirichlet Laplanian in R~2 and tr_b~Γ is a fractal potential(distribution) supported by Γ.  相似文献   

18.
Let Un be the unit polydisc of Cn and φ = (φ1,…,φn) a holomorphic self map of Un. This paper shows that the composition operator Cφ induced by φ is bounded on the little Bloch space β0*(Un) if and only if φ∈β0*(Un) for every l=1,2,…,n, and also gives a sufficient and necessary condition for the composition operator Cφ to be compact on the little Bloch spaceβ0* (Un).  相似文献   

19.
Let n>1 and B be the unit ball in n dimensions complex space Cn.Suppose thatφis a holomorphic self-map of B andψ∈H(B)withψ(0)=0.A kind of integral operator,composition Cesàro operator,is defined by Tφψ(f)(z)=∫10f[φ(tz)]Rψ(tz)dt/t,f∈(B)z∈B.In this paper,the authors characterize the conditions that the composition Cesàro operator T_φ,ψis bounded or compact on the normal weight Zygmund space Z_μ(B).At the same time,the sufficient and necessary conditions for all cases are given.  相似文献   

20.
Let f(x) = sum from t=0 to n α_ix~i∈GF(p)[x],we associate it with a ploynomial f~*(x)=sum from i=0 to n α_ix~(p~i),f(x) and f~*(x)are called p-associates of each other. f~*(x) is called a p-ploynomial,customary to speak of linearized polynomial. Let f(x)=x~m- 1/g(x), m = m_1~r, q = p~m, g(x)∈GF(p)[x],r be the order of g(x). Cohen and the author observed that if m_1≥2, there alwaysexsists a primitive roots ζ∈GF(q) suck that f~*(ζ) = f~*(c), here f~*(c)≠0. In fact  相似文献   

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