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1.
Zhu  Li 《The Ramanujan Journal》2020,51(2):307-318
The Ramanujan Journal - Suppose that $$\lambda _1,\ldots ,\lambda _5$$ are nonzero real numbers, not all of the same sign, satisfying that $$\frac{\lambda _1}{\lambda _2}$$ is irrational. Then for...  相似文献   

2.
We study the threshold θ ≥ 2 contact process on a homogeneous tree of degree κ = b + 1, with infection parameter λ ≥ 0 and started from a product measure with density p. The corresponding mean-field model displays a discontinuous transition at a critical point and for it survives iff , where this critical density satisfies , . For large b, we show that the process on has a qualitatively similar behavior when λ is small, including the behavior at and close to the critical point . In contrast, for large λ the behavior of the process on is qualitatively distinct from that of the mean-field model in that the critical density has . We also show that , where 1 < Φ2 < Φ3 < ..., , and . The work of L.R.F. was partially supported by the Brazilian CNPq through grants 307978/2004-4 and 475833/2003-1, and by FAPESP through grant 04/07276-2. The work of R.H.S. was partially supported by the American N.S.F. through grant DMS-0300672.  相似文献   

3.
Czechoslovak Mathematical Journal - Let $${{\cal D}_{\lambda ,\mu }}$$ be the space of linear differential operators on weighted densities from $${{\cal F}_\lambda }$$ to $${{\cal F}_\mu }$$ as...  相似文献   

4.
Qu  Yunyun  Zeng  Jiwen 《The Ramanujan Journal》2020,52(3):625-639
The Ramanujan Journal - Suppose that $$\lambda _1, \lambda _2, \lambda _3, \lambda _4$$ are positive real numbers and $$\frac{\lambda _1}{\lambda _2}$$ is irrational and algebraic. Let $$\mathcal...  相似文献   

5.
We characterize the group Aut for the symmetrized bidisc
Both authors were supported in part by KBN grant no. 5 P03A 033 21 and by DFG grant no. 227/8-1.  相似文献   

6.
Solutions with asymptotics in integral and fractional powers of the parameter ? are constructed for the vector differential equation $$\varepsilon ^h \dot X = A(t,\varepsilon ) X + \varepsilon ^{\alpha _1 } p(t,\varepsilon ) \exp \left( {\varepsilon ^{ - h} \int\limits_0^t {\lambda (\tau )d\tau } } \right)$$ in the case of resonance and multiple spectrum of the limit matrix. $$\varepsilon ^h \dot X = A(t,\varepsilon ) X + \varepsilon ^{\alpha _1 } p(t,\varepsilon ) \exp \left( {\varepsilon ^{ - h} \int\limits_0^t {\lambda (\tau )d\tau } } \right)$$   相似文献   

7.
We establish a symbol calculus for the C*-subalgebra of generated by the operators of multiplication by slowly oscillating and piecewise continuous functions and the operators where is the Cauchy singular integral operator and The C*-algebra is invariant under the transformations
where Uz is the rotation operator Using the localtrajectory method, which is a natural generalization of the Allan-Douglas local principle to nonlocal type operators, we construct symbol calculi and establish Fredholm criteria for the C*-algebra generated by the operators and for the C*-algebra generated by the operators and and for the C*-algebra generated by the algebras and The C*-algebra can be considered as an algebra of convolution type operators with piecewise slowly oscillating coefficients and shifts acting freely.  相似文献   

8.
We consider *-automorphisms and *-antiautomorphisms of real and complex factors. We establish both the uniqueness of the class of *-automorphisms (with ) of a real injective factor and the uniqueness of the class of *-antiautomorphisms (with ) of a complex injective factor. It is well known that, for complex factors, the notions of hyperfiniteness and injectivity are equivalent. Here we prove that, for real factors, the two notions are no longer equivalent. Bibliography: 15 titles.  相似文献   

9.
Liu  Yuhui 《The Ramanujan Journal》2021,56(2):411-423
The Ramanujan Journal - Let k be a positive integer with $$k \ge 5$$ , $$\lambda _1, \lambda _2, \lambda _3, \lambda _4$$ be nonzero real numbers, not all of the same sign, with $$\lambda...  相似文献   

10.
This paper considers the approximation of the Kantorovich–Shepard operators in spaces for . For the Kantorovich–Shepard operators are defined by (1.1). Then
where is a positive number depending only on and , and $$ \varepsilon_{n} =\cases{ n^{-1}, & if \ 2$$ " align="middle" border="0"> ; \cr\nosm n^{-1}\log n, & if \ ; \cr\nosm n^{1-\lambda}, & if \ . \cr} $$  相似文献   

11.
This paper concerns boundary value problems for quasilinear second order elliptic systems which are, for example, of the type
Here Ω is a Lipschitz domain in νj are the components of the unit outward normal vector field on ∂Ω, the sets Γβ are open in ∂Ω and their relative boundaries are Lipschitz hypersurfaces in ∂Ω. The coefficient functions are supposed to be bounded and measurable with respect to the space variable and smooth with respect to the unknown vector function u and to the control parameter λ. It is shown that, under natural conditions, such boundary value problems generate smooth Fredholm maps between appropriate Sobolev-Campanato spaces, that the weak solutions are H?lder continuous up to the boundary and that the Implicit Function Theorem and the Newton Iteration Procedure are applicable.  相似文献   

12.
Acta Mathematica Hungarica - We get a version of the colouring property Pr1 proving $$\Pr_1(\lambda,\lambda,\lambda,\partial)$$ always when $$\lambda= \partial^+,\partial $$ are regular cardinals...  相似文献   

13.
For an idealJ on an infinite setX with add(J)=κ, let be the smallest size of any subfamilyY ofJ with the property that any member ofJ can be covered by less than κ members ofY. We study the value of forA in , where denotes the smallest [δ] ideal onP κ(λ). We also discuss the problem of whether there exists a setA such that , or even . Some of the material in this paper originally appeared as part of the author's doctoral dissertation completed at the Université de Caen, 1998. Partially supported by the Israel Science Foundation. Publication 813.  相似文献   

14.
Journal of Algebraic Combinatorics - Recently, Skjelnes and Smith classified which Hilbert schemes on projective space are smooth in terms of integer partitions $$\lambda = (\lambda _1,\ldots...  相似文献   

15.
A constructive method of obtaining unbiased estimates of the unknown parameters and characteristics of a continuous finite Markow chain (CMC) ν(t), t≥0, with states 1, 2, ..., k and constant transition intensitiesλ i,j<∞, i≠j, i, j=1, 2,..., k; $$\lambda _{i,i} = 0,\quad q_i = \sum\limits_{j = 1}^k {\lambda _{i,j} } ,\quad i = 1, 2,..., k,$$ is considered in the present paper for a wide class of stopping rules.  相似文献   

16.
Получены новые оценк иL-нормы тригонометр ических полиномов $$T_n (t) = \frac{{\lambda _0 }}{2} + \mathop \sum \limits_{k = 1}^n \lambda _k \cos kt$$ в терминах коэффицие нтовλ k и их разностейΔλ k=λ k?λ k?1: (1) $$\mathop \smallint \limits_{ - \pi }^\pi |T_n (t)|dt \leqq \frac{c}{n}\mathop \sum \limits_{k = 0}^n |\lambda _\kappa | + c\left\{ {x(n,\varphi )\mathop \sum \limits_{k = 0}^n \Delta \lambda _\kappa \mathop \sum \limits_{l = 0}^n \Delta \lambda _l \delta _{\kappa ,l} (\varphi )} \right\}^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} ,$$ где $$\kappa (n,\varphi ) = \mathop \smallint \limits_{1/n}^\pi [t^2 \varphi (t)]^{ - 1} dt, \delta _{k,1} (\varphi ) = \mathop \smallint \limits_0^\infty \varphi (t)\sin \left( {k + \frac{1}{2}} \right)t \sin \left( {l + \frac{1}{2}} \right)t dt,$$ a ?(t) — произвольная фун кция ≧0, для которой опр еделены соответствующие инт егралы. Из (1) следует, что методы $$\tau _n (f;t) = (N + 1)^{ - 1} \mathop \sum \limits_{k = 0}^{\rm N} S_{[2^{k^\varepsilon } ]} (f;t), n = [2^{N\varepsilon } ],$$ являются регулярным и для всех 0<ε≦1/2. ЗдесьS m (f, x) частные суммы ряда Фу рье функцииf(x). В статье исследуется многомерный случай. П оказано, что метод суммирования (о бобщенный метод Рисса) с коэффиц иентами $$\lambda _{\kappa ,l} = (R^v - k^\alpha - l^\beta )^\delta R^{ - v\delta } (0 \leqq k^\alpha + l^\beta \leqq R^v ;\alpha \geqq 1,\beta \geqq 1,v< 0)$$ является регулярным, когда δ > 1.  相似文献   

17.
The zero-mean process is said to be almost periodically correlated whenever its shifted covariance kernel is almost periodic in t uniformly with respect to . Then it admits a Fourier–Bohr decomposition: . This paper deals with the estimation of the spectral covariance a(λ,τ) from a discrete time observation of the process , when jitter and delay phenomena are present in conjunction with periodic sampling. Under mixing conditions, we establish the consistency and the asymptotic normality of empirical estimators as the sampling time step tends to 0 and the sampling period tends to infinity.   相似文献   

18.
In this paper, we consider a linearly elastic shell, i.e. a three-dimensional linearly elastic body with a small thickness denoted by 2ε, which is clamped along its part of the lateral boundary and subjected to the regular loads. In the linear case, one can use the two-dimensional models of Ciarlet or Koiter to calculate the displacement for the shell. Some error estimates between the approximate solution of these models and the three-dimensional displacement vector field of a flexural or membrane shell have been obtained. Here we give a new model for a linear and nonlinear shell, prove that there exists a unique solution U of the two-dimensional variational problem and construct a three-dimensional approximate solutions UKT(x,ξ) in terms of U: We also provide the error estimates between our model and the three-dimensional displacement vector field :‖u-UKT‖1,Ω≤C∈r,r=3/2, an elliptic membrane, r = 1/2, a general membrane, where C is a constant dependent only upon the data‖u‖3,Ω,‖UKT‖3,Ω,θ.  相似文献   

19.
The locally best invariant test for the hypothesis of independence in bivariate distributions with exponentially distributed marginals is derived. The model consists of a family of bivariate exponential distributions with probability density function $$f_\theta (x_1 ,x_2 ;\lambda _1 ,\lambda _2 ) = \lambda _1 \lambda _2 \exp [ - (\lambda _1 x_1 + \lambda _2 x_2 )]g(\lambda _1 x_1 ,\lambda _2 x_2 ;\theta )$$ with unknown scale parameter γ j (j=1, 2) and association parameter ? which includes the independence situation. The locally best invariant (LBI) test is derived and the asymptotic null and nonnull distributions are also derived under some regularity conditions. The results are applied to the Gumbel (1960,J. Amer. Statist. Assoc.,55, 698–707), Frank (1979,Aequationes Math.,19, 194–226, and Cook and Johnson (1981),J. Roy. Statist. Soc. Ser. B,43, 210–218) families.  相似文献   

20.
Yee  Ae Ja 《The Ramanujan Journal》2001,5(3):247-262
A lecture hall partition of length n is an integer sequence satisfying Bousquet-Mélou and Eriksson showed that the number of lecture hall partitions of length n of a positive integer N whose alternating sum is k equals the number of partitions of N into k odd parts less than 2n. We prove the fact by a natural combinatorial bijection. This bijection, though defined differently, is essentially the same as one of the bijections found by Bousquet-Mélou and Eriksson.  相似文献   

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