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1.
Let ƒ be a birational map of C
d
,and consider the degree complexity or asymptotic degree growth rate δ(ƒ) = limn → ∞ (deg(ƒn))1/n.We introduce a family of elementary maps, which have the form ƒ = L o J, where L is (invertible) linear, and J(x
1
−1
,..., xd) = (x
1
−1
,...,x
d
−1
.We develop a method of regularization and show how it can be used to compute δ for an elementary map. 相似文献
2.
In this paper, we prove the algebraic independence of the reciprocal sums of odd terms in Fibonacci numbers ∑
n=1∞
F
2n−1−1, ∑
n=1∞
F
2n−1−2, ∑
n=1∞
F
2n−1−3 and write each ∑
n=1∞
F
2n−1−s
(s≥4) as an explicit rational function of these three numbers over ℚ. Similar results are obtained for various series including
the reciprocal sums of odd terms in Lucas numbers.
相似文献
3.
Hao Li 《Graphs and Combinatorics》2000,16(3):319-335
Let G be a 3-connected graph of order n and S a subset of vertices. Denote by δ(S) the minimum degree (in G) of vertices of S. Then we prove that the circumference of G is at least min{|S|, 2δ(S)} if the degree sum of any four independent vertices of S is at least n+6. A cycle C is called S-maximum if there is no cycle C
′ with |C
′∩S|>|C∩S|. We also show that if ∑4
i=1
d(a
i)≥n+3+|⋂4
i=1
N(a
i)| for any four independent vertices a
1, a
2, a
3, a
4 in S, then G has an S-weak-dominating S-maximum cycle C, i.e. an S-maximum cycle such that every component in G−C contains at most one vertex in S.
Received: March 9, 1998 Revised: January 7, 1999 相似文献
4.
Let S′ be the class of tempered distributions. For ƒ ∈ S′ we denote by J
−α
ƒ the Bessel potential of ƒ of order α. We prove that if J
−α
ƒ ∈ BMO, then for any λ ∈ (0, 1), J
−α
(f)λ ∈ BMO, where (f)λ = λ−n
f(φ(λ−1)), φ ∈ S. Also, we give necessary and sufficient conditions in order that the Bessel potential of a tempered distribution of order
α > 0 belongs to the VMO space. 相似文献
5.
Shiri Artstein-Avidan Omer Friedland Vitali Milman Sasha Sodin 《Israel Journal of Mathematics》2006,156(1):141-155
We present a quantitative form of the result of Bai and Yin from [2], and use to show that the section of ℓ
1
(1+δ)n
spanned byn random independent sign vectors is with high probability isomorphic to euclidean with isomorphism constant polynomial in
δ−1.
Partially supported by BSF grant 2002-006.
Supported by the National Science Foundation under agreement No. DMS-0111298.
Supported in part by the Israel Science Academy. 相似文献
6.
LetF be a distribution and letf be a locally summable function. The distributionF(f) is defined as the neutrix limit of the sequenceF
n
(f), whereF
n
(x) = F(x) * δ
n
(x) andδ
n
(x) is a certain sequence of infinitely differentiable functions converging to the Dirac delta-functionδ(x). The distribution (xr)−s is valuated forr, s = 1,2, …. 相似文献
7.
Hyunsuk Moon 《The Ramanujan Journal》2008,16(1):73-81
Let F(z)=∑
n=1∞
A(n)q
n
denote the unique weight 6 normalized cuspidal eigenform on Γ0(4). We prove that A(p)≡0,2,−1(mod 11) when p≠11 is a prime. We then use this congruence to give an application to the number of representations of an integer by quadratic
form of level 4.
相似文献
8.
Nariaki Sugiura 《Annals of the Institute of Statistical Mathematics》1974,26(1):117-125
Summary LetS
i have the Wishart distributionW
p(∑i,ni) fori=1,2. An asymptotic expansion of the distribution of
for large n=n1+n2 is derived, when∑
1∑
2
−1
=I+n−1/2θ, based on an asymptotic solution of the system of partial differential equations for the hypergeometric function2
F
1, obtained recently by Muirhead [2]. Another asymptotic formula is also applied to the distributions of −2 log λ and −log|S
2(S
1+S
2)−1| under fixed∑
1∑
2
−1
, which gives the earlier results by Nagao [4]. Some useful asymptotic formulas for1
F
1 were investigated by Sugiura [7]. 相似文献
9.
Let f(z)=∑
n=1∞
λ
f
(n)n
(κ−1)/2
e(nz) be a holomorphic cusp form of weight κ for the full modular group SL
2(ℤ). In this paper we study the cancellation of the coefficients λ
f
(n) over primes in exponential sums. 相似文献
10.
A hypersurface x : M → S n+1 without umbilic point is called a Möbius isoparametric hypersurface if its Möbius form Φ = ?ρ ?2∑ i (e i (H) + ∑ j (h ij ?Hδ ij )e j (log ρ))θ i vanishes and its Möbius shape operator $ {\Bbb {S}}A hypersurface x : M → S
n
+1 without umbilic point is called a M?bius isoparametric hypersurface if its M?bius form Φ = −ρ−2∑
i
(e
i
(H) + ∑
j
(h
ij
−Hδ
ij
)e
j
(log ρ))θ
i
vanishes and its M?bius shape operator ? = ρ−1(S−Hid) has constant eigenvalues. Here {e
i
} is a local orthonormal basis for I = dx·dx with dual basis {θ
i
}, II = ∑
ij
h
ij
θ
i
⊗θ
i
is the second fundamental form, and S is the shape operator of x. It is clear that any conformal image of a (Euclidean) isoparametric hypersurface in S
n
+1 is a M?bius isoparametric hypersurface, but the converse is not true. In this paper we classify all M?bius isoparametric
hypersurfaces in S
n
+1 with two distinct principal curvatures up to M?bius transformations. By using a theorem of Thorbergsson [1] we also show
that the number of distinct principal curvatures of a compact M?bius isoparametric hypersurface embedded in S
n
+1 can take only the values 2, 3, 4, 6.
Received September 7, 2001, Accepted January 30, 2002 相似文献
11.
B. Djafari Rouhani H. Khatibzadeh 《Journal of Optimization Theory and Applications》2008,137(2):411-417
Let A be a maximal monotone operator in a real Hilbert space H and let {u
n
} be the sequence in H given by the proximal point algorithm, defined by u
n
=(I+c
n
A)−1(u
n−1−f
n
), ∀
n≥1, with u
0=z, where c
n
>0 and f
n
∈H. We show, among other things, that under suitable conditions, u
n
converges weakly or strongly to a zero of A if and only if lim inf
n→+∞|w
n
|<+∞, where w
n
=(∑
k=1
n
c
k
)−1∑
k=1
n
c
k
u
k
. Our results extend previous results by several authors who obtained similar results by assuming A
−1(0)≠φ. 相似文献
12.
In this paper we study the order of growth of the uniform norm of the hyperinterpolation operator on the unit sphere S
r−1
⊂ Rr. The hyperinterpolation approximation L
n
ƒ, where ƒ ∈ C(S
r
−1), is derived from the exact L
2 orthogonal projection Π ƒ onto the space P
n
r
(S
r
−1) of spherical polynomials of degree n or less, with the Fourier coefficients approximated by a positive weight quadrature rule that integrates exactly all polynomials
of degree ≤ 2n. We extend to arbitrary r the recent r = 3 result of Sloan and Womersley [9], by proving that under an additional “quadrature regularity” assumption on the quadrature
rule, the order of growth of the uniform norm of the hyperinterpolation operator on the unit sphere is O(n
r
/2−1), which is the same as that of the orthogonal projection Πn, and best possible among all linear projections onto P
n
r
(S
r
−1). 相似文献
13.
Hei-Chi Chan 《数学学报(英文版)》2011,27(4):625-634
In this paper, we study a certain partition function a(n) defined by Σ
n≥0
a(n)q
n
:= Π
n=1(1 − q
n
)−1(1 − q
2n
)−1. We prove that given a positive integer j ≥ 1 and a prime m ≥ 5, there are infinitely many congruences of the type a(An + B) ≡ 0 (mod m
j
). This work is inspired by Ono’s ground breaking result in the study of the distribution of the partition function p(n). 相似文献
14.
Guizhen LIU 《Frontiers of Mathematics in China》2009,4(2):311-323
Let G be a digraph with vertex set V(G) and arc set E(G) and let g = (g
−, g
+) and ƒ = (ƒ
−, ƒ
+) be pairs of positive integer-valued functions defined on V(G) such that g
−(x) ⩽ ƒ
−(x) and g
+(x) ⩽ ƒ
+(x) for each x ∈ V(G). A (g, ƒ)-factor of G is a spanning subdigraph H of G such that g
−(x) ⩽ id
H
(x) ⩽ ƒ
−(x) and g
+(x) ⩽ od
H
(x) ⩽ ƒ
+(x) for each x ∈ V(H); a (g, ƒ)-factorization of G is a partition of E(G) into arc-disjoint (g, ƒ)-factors. Let
= {F
1, F
2,…, F
m} and H be a factorization and a subdigraph of G, respectively.
is called k-orthogonal to H if each F
i
, 1 ⩽ i ⩽ m, has exactly k arcs in common with H. In this paper it is proved that every (mg+m−1,mƒ−m+1)-digraph has a (g, f)-factorization k-orthogonal to any given subdigraph with km arcs if k ⩽ min{g
−(x), g
+(x)} for any x ∈ V(G) and that every (mg, mf)-digraph has a (g, f)-factorization orthogonal to any given directed m-star if 0 ⩽ g(x) ⩽ f(x) for any x ∈ V(G). The results in this paper are in some sense best possible.
相似文献
15.
Asymptotic Upper Bounds for Ramsey Functions 总被引:5,自引:0,他引:5
We show that for any graph G with N vertices and average degree d, if the average degree of any neighborhood induced subgraph is at most a, then the independence number of G is at least Nf
a
+1(d), where f
a
+1(d)=∫0
1(((1−t)1/(
a
+1))/(a+1+(d−a−1)t))dt. Based on this result, we prove that for any fixed k and l, there holds r(K
k
+
l
,K
n
)≤ (l+o(1))n
k
/(logn)
k
−1. In particular, r(K
k
, K
n
)≤(1+o(1))n
k
−1/(log n)
k
−2.
Received: May 11, 1998 Final version received: March 24, 1999 相似文献
16.
Vladimir A. Kozlov 《Arkiv f?r Matematik》1999,37(2):305-322
The equationx
(n)(t)=(−1)
n
│x(t)│
k
withk>1 is considered. In the casen≦4 it is proved that solutions defined in a neighbourhood of infinity coincide withC(t−t0)−n/(k−1), whereC is a constant depending only onn andk. In the general case such solutions are Kneser solutions and can be estimated from above and below by a constant times (t−t
0)−n/(k−1). It is shown that they do not necessarily coincide withC(t−t0)−n/(k−1). This gives a negative answer to two conjectures posed by Kiguradze that Kneser solutions are determined by their value in
a point and that blow-up solutions have prescribed asymptotics.
Dedicated to Professor Vladimir Maz'ya on the occasion of his 60th birthday.
The author was supported by the Swedish Natural Science Research Council (NFR) grant M-AA/MA 10879-304. 相似文献
17.
M. M. Sheremeta 《Ukrainian Mathematical Journal》1999,51(8):1296-1302
We establish the relation between the increase of the quantityM(σ,F) = ∣a
0∣ + ∑
n=1
∞
∣a
n
∣ exp (σλ
n
) and the behavior of sequences (|a
n
|) and (λ
n
), where (λ
n
) is a sequence of nonnegative numbers increasing to + ∞, andF(s) =a
0 + ∑
n=1
∞
a
n
e
sλn
,s=σ+it, is the Dirichlet entire series.
Lviv University, Lviv. Translated from Ukrainskii Matematicheskii Zhurmal, Vol. 51, No. 8, pp. 1149–1153, August, 1999. 相似文献
18.
K. Kubilius 《Lithuanian Mathematical Journal》1999,39(3):251-261
The uniform distance between the solution of a nonlinear equation driven by a functionh with boundedp-variation and its Milstein-type approximation is estimated by δ
n
v γ
p
(n) v γ
p
2
(n), where δ
n
=max(t
k
−t
k−1
) is the maximum step size of the approximation on the interval [0,T], γ
p
(n)=max υ
p
1/p
(h;[t
k-1,t
k
]), 1 <p < 2, and υ
p
(h;[t
k-1,t
k
]) is thep-variation of the functionh on [t
k-1,t
k]. In particular, ifh is a Lipschitz function of order α, then the uniform distance has the bound δ
n
α
for δn <1.
Institute of Mathematics and Informatics, Akademijos 4, 2600 Vilnius; Vilnius Technical University, Saulétekio 11, 2054 Vilnius,
Lithuania. Published in Lietuvos Matematikos Rinkinys, Vol. 39, No. 3, pp. 317–330, July–September, 1999. 相似文献
19.
We study self adjoint operators of the form?H
ω = H
0 + ∑λω(n) <δ
n
,·>δ
n
,?where the δ
n
’s are a family of orthonormal vectors and the λω(n)’s are independently distributed random variables with absolutely continuous probability distributions. We prove a general
structural theorem saying that for each pair (n,m), if the cyclic subspaces corresponding to the vectors δ
n
and δ
m
are not completely orthogonal, then the restrictions of H
ω to these subspaces are unitarily equivalent (with probability one). This has some consequences for the spectral theory of
such operators. In particular, we show that “well behaved” absolutely continuous spectrum of Anderson type Hamiltonians must
be pure, and use this to prove the purity of absolutely continuous spectrum in some concrete cases.
Oblatum 27-V-1999 & 6-I-2000?Published online: 8 May 2000 相似文献
20.
Gerald Kuba 《Mathematica Slovaca》2009,59(3):349-356
Let ℛ
n
(t) denote the set of all reducible polynomials p(X) over ℤ with degree n ≥ 2 and height ≤ t. We determine the true order of magnitude of the cardinality |ℛ
n
(t)| of the set ℛ
n
(t) by showing that, as t → ∞, t
2 log t ≪ |ℛ2(t)| ≪ t
2 log t and t
n
≪ |ℛ
n
(t)| ≪ t
n
for every fixed n ≥ 3. Further, for 1 < n/2 < k < n fixed let ℛ
k,n
(t) ⊂ ℛ
n
(t) such that p(X) ∈ ℛ
k,n
(t) if and only if p(X) has an irreducible factor in ℤ[X] of degree k. Then, as t → ∞, we always have t
k+1 ≪ |ℛ
k,n
(t)| ≪ t
k+1 and hence |ℛ
n−1,n
(t)| ≫ |ℛ
n
(t)| so that ℛ
n−1,n
(t) is the dominating subclass of ℛ
n
(t) since we can show that |ℛ
n
(t)∖ℛ
n−1,n
(t)| ≪ t
n−1(log t)2.On the contrary, if R
n
s
(t) is the total number of all polynomials in ℛ
n
(t) which split completely into linear factors over ℤ, then t
2(log t)
n−1 ≪ R
n
s
(t) ≪ t
2 (log t)
n−1 (t → ∞) for every fixed n ≥ 2.
相似文献