共查询到20条相似文献,搜索用时 109 毫秒
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Let ■ be a k-uniform hypergraph on n vertices with degree sequence △= d1≥…≥ dn =δ. In this paper, in terms of degree di , we give some upper bounds for the Z-spectral radius of the signless Laplacian tensor (Q(■)) of ■. Some examples are given to show the efficiency of these bounds. 相似文献
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Xindong XU 《Frontiers of Mathematics in China》2018,13(1):227-254
We consider Hamiltonian partial differential equations utt +|∂x|u+ σu = f(u), x ∈ , t ∈ , with periodic boundary conditions, where f(u) is a real-analytic function of the form f(u) = u5 + o(u5) near u = 0, σ ∈ (0, 1) is a fixed constant, and T= R/2πZ. A family of quasi-periodic solutions with 2-dimensional are constructed for the equation above with σ ∈ (0, 1)\ . The proof is based on infinite-dimensional KAM theory and partial Birkhoff normal form. 相似文献
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Weili YAO 《Frontiers of Mathematics in China》2020,15(1):205-213
Let f be a holomorphic Hecke cusp form with even integral weight k≥2 for the full modular group,and letχbe a primitive Dirichlet character modulo q.Let Lf(s,χ)be the automorphic L-function attached to f andχ-We study the mean-square estimate of Lf(s,χ)and establish an asymptotic formula. 相似文献
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Xiaoguang HE 《Frontiers of Mathematics in China》2018,13(6):1355-1368
Let f be a Hecke-Maass cusp form for SL(3; ) with Fourier coefficients Af(m; n); and let (x) be a -function supported on [1; 2] with derivatives bounded by 1. We prove an asymptotic formula for the nonlinear exponential sum , where and 相似文献
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Yuchao WANG 《Frontiers of Mathematics in China》2015,10(6):1449
value of a given binary linear form at prime arguments. Let λ1 and λ2 be positive real numbers such that λ1/λ2 is irrational and algebraic. For any (C, c) well-spaced sequence V and δ>0, let E(V , X, δ) denote the number of υ∈V with υ≤X for which the inequality | λ 1 p 1 + λ 2 ρ 2 − υ | < υ − δ has no solution in primes p1, p2. It is shown that for any ε>0,we have E(V , X, δ) «max(X 3 5 + 2 δ + ε , X 2 3 + 4 3 δ + ε ). 相似文献
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Consider the flag-transitive 2-(v, k, λ) symmetric designs with (k, λ) = 1. We prove that if is a nontrivial 2-(v, k, λ) symmetric design with (k, λ) = 1 and G≤Aut( ) is flag-transitive with Soc(G) = An for n≥5, then is the projective space PG2(3,2) and G = A7. 相似文献
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Let be a complete Riemannian manifold with , and let be two complete totally geodesic submanifolds in M. We prove that if n1 + n2 = n − 2 and if the distance , then Mi is isometric to , or with the canonical metric when ni>0, and thus, M is isometric to , or except possibly when n = 3 and M1 (or M2) with or n = 4 and M1 (or M2) . 相似文献
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Xie-Bin CHEN 《Frontiers of Mathematics in China》2019,14(6):1117
We consider the problem of existence of a Hamiltonian cycle containing a matching and avoiding some edges in an n-cube , and obtain the following results. Let , and with . If M is a matching and every vertex is incident with at least two edges in the graph , then all edges of M lie on a Hamiltonian cycle in . Moreover, if or , then the upper bound of number of faulty edges tolerated is sharp. Our results generalize the well-known result for . 相似文献
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We study a superminimal surface M immersed into a hyperquadric Q2 in several cases classified by two global defined functions and , which were introduced by X. X. Jiao and J. Wang to study a minimal immersion f : . In case both and are not identically zero, it is proved that f is superminimal if and only if f is totally real or is also minimal, where is the standard inclusion map. In the rest case that or , the minimal immersion f is automatically superminimal. As a consequence, all the superminimal two-spheres in Q2 are completely described. 相似文献
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We study the derivative operator of the generalized spherical mean S^γt. By considering a more general multiplier m^Ωγ,b=Vn-2/2+γ(|ξ|)|ξ|^bΩ(ξ') and finding the smallest γ such that m^Ωγ,b is an Hp multiplier, we obtain the optimal range of exponents (γ,β,p)to ensure the H^p(R^n) boundedness of a^βS^γ1f(x). As an application, we obtain the derivative estimates for the solution for the Cauchy problem of the wave equation on H^p(R^n) spaces. 相似文献
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Let M be a 2n-dimensional closed unitary manifold with a Tn−1-action with only isolated fixed points. In this paper, we first prove that the equivariant cobordism class of a unitary Tn−1-manifold M is just determined by the equivariant Chern numbers [M],where ω= (i1, i2, ..., i6) are the multi-indexes for all i1, i2, ..., i6∈ . Then we show that if Mdoes not bound equivariantly, then the number of fixed points is greater than or equal to , where denotes the minimum integer no less than n/6. 相似文献
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Let c>1 and : We study the solubility of the Diophantine inequality in Piatetski-Shapiro primes p1,p2, .., ps of the form for some , and improve the previous results in the cases s = 2, 3, 4. 相似文献
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We give a two sided estimate on the spectral gap for the Boltzmann measures μh on the circle. We prove that the spectral gap is greater than 1 for any and the spectral gap tends to the positive infinity as with speed . 相似文献
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This paper is a subsequent work of [Invent. Math., 2013, 191: 197-253]. The second fundamental theorem in Ahlfors covering surface theory is that, for each set Eq of q (≥3) distinct points in the extended complex plane ; there is a minimal positive constant H0 (Eq) (called Ahlfors constant with respect to Eq), such that the inequality holds for any simply-connected surface ; where A( ) is the area of ; L( ) is the perimeter of ; and # denotes the cardinality. It is difficult to compute H0 (Eq) explicitly for general set Eq; and only a few properties of H0(Eq) are known. The goals of this paper are to prove the continuity and differentiability of H0 (Eq); to estimate H0 (Eq); and to discuss the minimum of H0 (Eq) for fiixed q. 相似文献
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Submanifolds in space forms satisfy the well-known DDVV inequality. A submanifold attaining equality in this inequality pointwise is called a Wintgen ideal submanifold. As conformal invariant objects, Wintgen ideal submanifolds are investigated in this paper using the framework of M?bius geometry. We classify Wintgen ideal submanfiolds of dimension m ≥ 3 and arbitrary codimension when a canonically defined 2-dimensional distribution ? 2 is integrable. Such examples come from cones, cylinders, or rotational submanifolds over super-minimal surfaces in spheres, Euclidean spaces, or hyperbolic spaces, respectively. We conjecture that if ? 2 generates a k-dimensional integrable distribution ? k and k<m, then similar reduction theorem holds true. This generalization when k = 3 has been proved in this paper. 相似文献
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Consider a time-inhomogeneous branching random walk, generated by the point process Ln which composed by two independent parts: ‘branching’offspring Xn with the mean for and ‘displacement’ with a drift for , where the ‘branching’ process is supercritical for B>0 but ‘asymptotically critical’ and the drift of the ‘displacement’ is strictly positive or negative for but ‘asymptotically’ goes to zero as time goes to infinity. We find that the limit behavior of the minimal (or maximal) position of the branching random walk is sensitive to the ‘asymptotical’ parameter and . 相似文献
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Miao LOU 《Frontiers of Mathematics in China》2019,14(1):123-134
Let f be a full-level cusp form for GLm(Z) with Fourier coefficients Af(cm-2,…, c1, n): Let λ(n) be either the von Mangoldt function Λ(n) or the k-th divisor function τk(n): We consider averages of shifted convolution sums of the type Σ|h|≤H |ΣX相似文献