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1.
We find some logarithmic and exact small deviation asymptotics for the L
2-norms of certain Gaussian processes closely connected with a Wiener process. In particular, processes obtained by centering and integrating Brownian motion and Brownian bridge are examined. Bibliography: 28 titles.__________Published in Zapiski Nauchnykh Seminarov POMI, Vol. 298, 2003, pp. 5–21. 相似文献
2.
A.I. Nazarov 《Journal of Mathematical Sciences》2003,117(3):4185-4210
We find the sharp constant in the small L
2-deviation asymptotics for a wide class of Gaussian processes including the m-times integrated Wiener process and the m-times integrated Ornstein–Uhlenbeck process. Extremal properties of usual and Euler integration are proved. Bibliography: 19 titles. 相似文献
3.
We find the exact small ball asymptotics under weighted L
2-norm for a wide class of Gaussian processes which generate boundary-value problems for ordinary differential equations. Sharp
constants in the asymptotics are derived for a number of processes connected with special functions. Bibliography: 23 titles. 相似文献
4.
A. Muthusamy 《Graphs and Combinatorics》2004,20(3):377-382
A necessary and sufficient condition for the existence of a km–factorization of the complete symmetric k–partite multi-digraph K*(n1,n2,...,nk) is obtained for odd k. As a consequence, a resolvable (k,n,km,) multipartite km–design exists for odd k if and only if m|n. This deduces a result of Ushio when m=1 and k=3. Further, a necessary and sufficient condition for the existence of a km–factorization of is established for even k, where denotes the wreath product of graphs. Finally, a simple and short proof for the non-existence of a k–factorization of is obtained for odd k.Acknowledgments.The author thanks Dr. P. Paulraja for his useful ideas in writing this paper and the Department of Science and Technology, New Delhi, for its support (Project Grant No. DST/MS/103/99).Final version received: November 17, 2003 相似文献
5.
The following results are proved. In Theorem 1, it is stated that there exist both finitely presented and not finitely presented
2-generated nonfree groups which are k-free-like for any k ⩾ 2. In Theorem 2, it is claimed that every nonvirtually cyclic (resp., noncyclic and torsion-free) hyperbolic m-generated group is k-free-like for every k ⩾ m + 1 (resp., k ⩾ m). Finally, Theorem 3 asserts that there exists a 2-generated periodic group G which is k-free-like for every k ⩾ 3.
Supported by NSF (grant Nos. DMS 0455881 and DMS-0700811). (A. Yu. Olshanskii, M. V. Sapir)
Supported by RFBR project No. 08-01-00573. (A. Yu. Olshanskii)
Supported by BSF grant (USA–Israel). (M. V. Sapir)
Translated from Algebra i Logika, Vol. 48, No. 2, pp. 245–257, March–April, 2009. 相似文献
6.
S. B. Yakubovich 《Lithuanian Mathematical Journal》2005,45(1):102-122
We establish the boundedness properties in L
p
for a class of integral transformations with respect to an index of hypergeometric functions. In particular, by using the Riesz-Thorin interpolation theorem, we get the corresponding results in L
p
(R
+), 1 p 2, for the Kontorovich-Lebedev, Mehler-Fock, and Olevskii index transforms. An inversion theorem is proved for a general index transformation. The case p=2 is known as the Plancherel-type theory for this class of transformations.__________Published in Lietuvos Matematikos Rinkinys, Vol. 45, No. 1, pp. 127–147, January–March, 2005. 相似文献
7.
Multivariate Refinement Equations and Convergence of Cascade Algorithms in Lp(0〈p〈1)Spaces 总被引:1,自引:0,他引:1
SongLI 《数学学报(英文版)》2003,19(1):97-106
We consider the solutions of refinement equations written in the form
where the vector of functions ϕ = (ϕ
1, ..., ϕ
r
)
T
is unknown, g is a given vector of compactly supported functions on ℝ
s
, a is a finitely supported sequence of r × r matrices called the refinement mask, and M is an s × s dilation matrix with m = |detM|. Inhomogeneous refinement equations appear in the construction of multiwavelets and the constructions of wavelets on a finite
interval. The cascade algorithm with mask a, g, and dilation M generates a sequence ϕ
n
, n = 1, 2, ..., by the iterative process
from a starting vector of function ϕ
0. We characterize the L
p
-convergence (0 < p < 1) of the cascade algorithm in terms of the p-norm joint spectral radius of a collection of linear operators associated with the refinement mask. We also obtain a smoothness
property of the solutions of the refinement equations associated with the homogeneous refinement equation.
This project is supported by the NSF of China under Grant No. 10071071 相似文献
8.
The j-function j(z) = q−1+ 744 + 196884q + ⋅s plays an important role in many problems. In [7], Zagier, presented an interesting series of functions obtained from the
j-function: jm(ζ) = (j(ζ) – 744)∨T0(m), where T0(m) is the usual m′th normalized weight 0 Hecke operator. In [3], Bruinier et al. show how this series of functions can be used to describe
all meromorphic modular forms on SL2(ℤ). In this note we use these functions and basic notions about modular forms to determine previously unidentified congruence
relations between the coefficients of Eisenstein series and the j-function.
2000 Mathematics Subject Classification: Primary–11B50, 11F03, 11F30
The author thanks the National Science Foundation for their generous support. 相似文献
9.
We determine the L
p
discrepancy of the two-dimensional Hammersley point set in base b. These formulas show that the L
p
discrepancy of the Hammersley point set is not of best possible order with respect to the general (best possible) lower bound
on L
p
discrepancies due to Roth and Schmidt. To overcome this disadvantage we introduce permutations in the construction of the
Hammersley point set and show that there always exist permutations such that the L
p
discrepancy of the generalized Hammersley point set is of best possible order. For the L
2 discrepancy such permutations are given explicitly.
F.P. is supported by the Austrian Science Foundation (FWF), Project S9609, that is part of the Austrian National Research
Network “Analytic Combinatorics and Probabilistic Number Theory”. 相似文献
10.
Jan De Beule Patrick Govaerts Anja Hallez Leo Storme 《Designs, Codes and Cryptography》2009,50(2):187-201
Minihypers are substructures of projective spaces introduced to study linear codes meeting the Griesmer bound. Recently, many
results in finite geometry were obtained by applying characterization results on minihypers (De Beule et al. 16:342–349, 2008;
Govaerts and Storme 4:279–286, 2004; Govaerts et al. 28:659–672, 2002). In this paper, using characterization results on certain
minihypers, we present new results on tight sets in classical finite polar spaces and weighted m-covers, and on weighted m-ovoids of classical finite generalized quadrangles. The link with minihypers gives us characterization results of i-tight sets in terms of generators and Baer subgeometries contained in the Hermitian and symplectic polar spaces, and in terms
of generators for the quadratic polar spaces. We also present extendability results on partial weighted m-ovoids and partial weighted m-covers, having small deficiency, to weighted m-covers and weighted m-ovoids of classical finite generalized quadrangles. As a particular application, we prove in an alternative way the extendability
of 53-, 54-, and 55-caps of PG(5,3), contained in a non-singular elliptic quadric Q−(5,3), to 56-caps contained in this elliptic quadric Q−(5,3).
相似文献
11.
Let {εt;t ∈ Z} be a sequence of m-dependent B-valued random elements with mean zeros and finite second moment. {a3;j ∈ Z} is a sequence of real numbers satisfying ∑j=-∞^∞|aj| 〈 ∞. Define a moving average process Xt = ∑j=-∞^∞aj+tEj,t ≥ 1, and Sn = ∑t=1^n Xt,n ≥ 1. In this article, by using the weak convergence theorem of { Sn/√ n _〉 1}, we study the precise asymptotics of the complete convergence for the sequence {Xt; t ∈ N}. 相似文献
12.
(t,m,s)-Nets were defined by Niederreiter [Monatshefte fur Mathematik, Vol. 104 (1987) pp. 273–337], based on earlier work by Sobol’ [Zh. Vychisl Mat. i mat. Fiz, Vol. 7 (1967) pp. 784–802], in the context of quasi-Monte Carlo methods of numerical integration. Formulated in combinatorial/coding theoretic terms a binary linear (m−k,m,s)2-net is a family of ks vectors in F2m satisfying certain linear independence conditions (s is the length, m the dimension and k the strength: certain subsets of k vectors must be linearly independent). Helleseth et al. [5] recently constructed (2r−3,2r+2,2r−1)2-nets for every r. In this paper, we give a direct and elementary construction for (2r−3,2r+2,2r+1)2-nets based on a family of binary linear codes of minimum distance 6.Communicated by: T. Helleseth 相似文献
13.
The rank of a q-ary code C is the dimension of the subspace spanned by C. The kernel of a q-ary code C of length n can be defined as the set of all translations leaving C invariant. Some relations between the rank and the dimension of the kernel of q-ary 1-perfect codes, over
as well as over the prime field
, are established. Q-ary 1-perfect codes of length n=(qm − 1)/(q − 1) with different kernel dimensions using switching constructions are constructed and some upper and lower bounds for the dimension of the kernel, once the rank is given, are established.Communicated by: I.F. Blake 相似文献
14.
15.
In this paper we study the L
p
-discrepancy of digitally shifted Hammersley point sets. While it is known that the (unshifted) Hammersley point set (which
is also known as Roth net) with N points has L
p
-discrepancy (p an integer) of order (log N)/N, we show that there always exists a shift such that the digitally shifted Hammersley point set has L
p
-discrepancy (p an even integer) of order
which is best possible by a result of W. Schmidt. Further we concentrate on the case p = 2. We give very tight lower and upper bounds for the L
2-discrepancy of digitally shifted Hammersley point sets which show that the value of the L
2-discrepancy of such a point set mostly depends on the number of zero coordinates of the shift and not so much on the position
of these.
This work is supported by the Austrian Research Fund (FWF), Project P17022-N12 and Project S8305. 相似文献
16.
Adaptive approximation (or interpolation) takes into account local variations in the behavior of the given function, adjusts
the approximant depending on it, and hence yields the smaller error of approximation. The question of constructing optimal
approximating spline for each function proved to be very hard. In fact, no polynomial time algorithm of adaptive spline approximation can be designed and no exact
formula for the optimal error of approximation can be given. Therefore, the next natural question would be to study the asymptotic
behavior of the error and construct asymptotically optimal sequences of partitions. In this paper we provide sharp asymptotic
estimates for the error of interpolation by splines on block partitions in
\mathbbRd{\mathbb{R}^d} . We consider various projection operators to define the interpolant and provide the analysis of the exact constant in the
asymptotics as well as its explicit form in certain cases. 相似文献
17.
In this work the classification of filiform Leibniz superalgebras of nilindex n + m, where n and m (m≠0) are dimensions of even and odd parts, respectively, is obtained. 相似文献
18.
Alexander I. Nazarov 《Journal of Theoretical Probability》2009,22(3):640-665
We sharpen a classical result on the spectral asymptotics of boundary-value problems for self-adjoint ordinary differential
operator. Using this result, we obtain the exact L
2-small ball asymptotics for a new class of zero-mean Gaussian processes. This class includes, in particular, the integrated
generalized Slepian process, integrated centered Wiener process, and integrated centered Brownian bridge.
Partially supported by RFFR grant No.07-01-00159 and by grant NSh-227.2008.1. 相似文献
19.
Let X be a smooth closed oriented non-spin 4-manifold with even intersection form kE8nH (n1). The -conjecture states that n is greater than or equal to |k|. In this paper we give a proof of the -conjecture. The strategy of this paper is to use the finite dimensional approximation of the map induced from the Seiberg-Witten equations and equivariant eC-invariants as in the paper of M. Furuta and Y. Kametani.Mathematics Subject Classification (1991): 57R55This work was supported by Korea Research Foundation Grant (KRF–2002–003–C00011). 相似文献
20.
It is proved that association schemes with bipartite basis graphs are exactly 2-schemes. This result follows from a characterization
of p-schemes for an arbitrary prime p in terms of basis digraphs.
Second author work was partially supported by RFFI Grants 07-01-00485, 08-01-00379 and 08-01-00640. First author was visiting
the Euler Institute of Mathematics, St. Petersburg, Russia during the time a part of this paper was written and he thanks
the Euler Institute for its hospitality 相似文献