共查询到20条相似文献,搜索用时 531 毫秒
1.
We generalize the results of [11] and [12] for the unit ball $
\mathbb{B}_d
$
\mathbb{B}_d
of ℂ
d
. In particular, we show that under the weight condition (B) the weighted H
∞-space on $
\mathbb{B}_d
$
\mathbb{B}_d
is isomorphic to ℓ∞ and thus complemented in the corresponding weighted L
∞-space. We construct concrete, generalized Bergman projections accordingly. We also consider the case where the domain is
the entire space ℂ
d
. In addition, we show that for the polydisc $
\mathbb{D}^d
$
\mathbb{D}^d
d
, the weighted H
∞-space is never isomorphic to ℓ∞. 相似文献
2.
3.
In this note we construct a function φ in L2(Bn,dμ) which is unbounded on any neighborhood of each boundary point of Bn such that Tφ is a trace class operator on weighted Bergman space Lα2(Bn,dμ) for several complex variables. 相似文献
4.
A. V. Stolyarov 《Russian Mathematics (Iz VUZ)》2010,54(11):56-65
In this paper, the following results are obtained: 1) It is proved that, in the fourth order differential neighborhood, a
regular hypersurface V
n−1 embedded into a projective-metric space K
n
, n ≥ 3, intrinsically induces a dual projective-metric space $
\bar K_n
$
\bar K_n
. 2) An invariant analytical condition is established under which a normalization of a hypersurface V
n−1 ⊂ K
n
(a tangential hypersurface $
\bar V_{n - 1}
$
\bar V_{n - 1}
⊂ $
\bar K_n
$
\bar K_n
) by quasitensor fields H
n
i
, H
i
($
\bar H_n^i
$
\bar H_n^i
, $
\bar H_i
$
\bar H_i
) induces a Riemannian space of constant curvature. If the two conditions are fulfilled simultaneously, the spaces R
n−1 and $
\bar R_{n - 1}
$
\bar R_{n - 1}
are spaces of the same constant curvature $
K = - \tfrac{1}
{c}
$
K = - \tfrac{1}
{c}
. 3) Geometric interpretations of the obtained analytical conditions are given. 相似文献
5.
Stevo Stević 《Siberian Mathematical Journal》2009,50(6):1098-1105
Let $
\mathbb{B}
$
\mathbb{B}
be the unit ball in ℂ
n
and let H($
\mathbb{B}
$
\mathbb{B}
) be the space of all holomorphic functions on $
\mathbb{B}
$
\mathbb{B}
. We introduce the following integral-type operator on H($
\mathbb{B}
$
\mathbb{B}
):
$
I_\phi ^g (f)(z) = \int\limits_0^1 {\operatorname{Re} f(\phi (tz))g(tz)\frac{{dt}}
{t}} ,z \in \mathbb{B},
$
I_\phi ^g (f)(z) = \int\limits_0^1 {\operatorname{Re} f(\phi (tz))g(tz)\frac{{dt}}
{t}} ,z \in \mathbb{B},
相似文献
6.
Let X and Y be two smooth Deligne-Mumford stacks and consider a pair of functions f: X → $
\mathbb{A}^1
$
\mathbb{A}^1
, g:Y → $
\mathbb{A}^1
$
\mathbb{A}^1
. Assuming that there exists a complex of sheaves on X × $
\mathbb{A}^1
$
\mathbb{A}^1
Y which induces an equivalence of D
b
(X) and D
b
(Y), we show that there is also an equivalence of the singular derived categories of the fibers f
−1(0) and g
−1(0). We apply this statement in the setting of McKay correspondence, and generalize a theorem of Orlov on the derived category
of a Calabi-Yau hypersurface in a weighted projective space, to products of Calabi-Yau hypersurfaces in simplicial toric varieties
with nef anticanonical class. 相似文献
7.
We obtain characterizations (and prove the corresponding equivalence of norms) of function spaces B
pq
sm
($
\mathbb{I}
$
\mathbb{I}
k
) and L
pq
sm
($
\mathbb{I}
$
\mathbb{I}
k
) of Nikol’skii-Besov and Lizorkin-Triebel types, respectively, in terms of representations of functions in these spaces by
Fourier series with respect to a multiple system $
\mathcal{W}_m^\mathbb{I}
$
\mathcal{W}_m^\mathbb{I}
of Meyer wavelets and in terms of sequences of the Fourier coefficients with respect to this system. We establish order-sharp
estimates for the approximation of functions in B
pq
sm
($
\mathbb{I}
$
\mathbb{I}
) and L
pq
sm
($
\mathbb{I}
$
\mathbb{I}
k
) by special partial sums of these series in the metric of L
r
($
\mathbb{I}
$
\mathbb{I}
k
) for a number of relations between the parameters s, p, q, r, and m (s = (s
1, ..., s
n
) ∈ ℝ+
n
, 1 ≤ p, q, r ≤ ∞, m = (m
1, ..., m
n
) ∈ ℕ
n
, k = m
1 +... + m
n
, and $
\mathbb{I}
$
\mathbb{I}
= ℝ or $
\mathbb{T}
$
\mathbb{T}
). In the periodic case, we study the Fourier widths of these function classes. 相似文献
8.
The set of all m × n Boolean matrices is denoted by $
\mathbb{M}
$
\mathbb{M}
m,n
. We call a matrix A ∈ $
\mathbb{M}
$
\mathbb{M}
m,n
regular if there is a matrix G ∈ $
\mathbb{M}
$
\mathbb{M}
n,m
such that AGA = A. In this paper, we study the problem of characterizing linear operators on $
\mathbb{M}
$
\mathbb{M}
m,n
that strongly preserve regular matrices. Consequently, we obtain that if min{m, n} ⩽ 2, then all operators on $
\mathbb{M}
$
\mathbb{M}
m,n
strongly preserve regular matrices, and if min{m, n} ⩾ 3, then an operator T on $
\mathbb{M}
$
\mathbb{M}
m,n
strongly preserves regular matrices if and only if there are invertible matrices U and V such that T(X) = UXV for all X ε $
\mathbb{M}
$
\mathbb{M}
m,n
, or m = n and T(X) = UX
T
V for all X ∈ $
\mathbb{M}
$
\mathbb{M}
n
. 相似文献
9.
A metric space M is said to have the fibered approximation property in dimension n (briefly, M ∈ FAP(n)) if for any ɛ > 0, m ≥ 0 and any map g: $
\mathbb{I}
$
\mathbb{I}
m
× $
\mathbb{I}
$
\mathbb{I}
n
→ M there exists a map g′: $
\mathbb{I}
$
\mathbb{I}
m
× $
\mathbb{I}
$
\mathbb{I}
n
→ M such that g′ is ɛ-homotopic to g and dim g′ ({z} × $
\mathbb{I}
$
\mathbb{I}
n
) ≤ n for all z ∈ $
\mathbb{I}
$
\mathbb{I}
m
. The class of spaces having the FAP(n)-property is investigated in this paper. The main theorems are applied to obtain generalizations of some results due to Uspenskij
[11] and Tuncali-Valov [10]. 相似文献
10.
Assume that no cardinal κ < 2
ω
is quasi-measurable (κ is quasi-measurable if there exists a κ-additive ideal
$
\mathbb{I}
$
\mathbb{I}
of X contains uncountably many pairwise disjoint subfamilies
$
\mathbb{I}
$
\mathbb{I}
-Bernstein unions ∪
$
\mathbb{I}
$
\mathbb{I}
-Bernstein if A and X \ A meet each Borel $
\mathbb{I}
$
\mathbb{I}
-positive subset B ⊆ X). This result is a generalization of the Four Poles Theorem (see [1]) and results from [2] and [4]. 相似文献
11.
A. A. Yukhimenko 《Moscow University Mathematics Bulletin》2010,65(2):69-71
The system of exponents $
\left\{ {e^{i\lambda _n t} } \right\}_{n \in \mathbb{Z}}
$
\left\{ {e^{i\lambda _n t} } \right\}_{n \in \mathbb{Z}}
is considered. A sufficient condition for a Riesz-property basis in the weighted space L
p
(−π, π) is obtained. 相似文献
12.
S. A. Nazarov 《Journal of Applied and Industrial Mathematics》2009,3(3):377-390
Taking various viewpoints, we study the selfadjoint extensions $
\mathcal{A}
$
\mathcal{A}
of the operator A of the Dirichlet problem in a 3-dimensional region Ω with an edge Γ. We identify the infinite dimensional nullspace def A with the Sobolev space H
−ϰ(Γ) on Γ with variable smoothness exponent −ϰ ∈ (−1, 0); while the selfadjoint extensions, with selfadjoint operators $
\mathcal{T}
$
\mathcal{T}
on the subspaces of H
−ϰ(Γ). To the boundary value problem in the region with a “smoothed” edge we associate a concrete extension, which yields a
more precise approximate solution to the singularly perturbed problem. 相似文献
13.
In the present paper we classify all surfaces in $
\mathbb{E}
$
\mathbb{E}
3 with a canonical principal direction. Examples of this type of surfaces are constructed. We prove that the only minimal surface
with a canonical principal direction in the Euclidean space $
\mathbb{E}
$
\mathbb{E}
3 is the catenoid. 相似文献
14.
B. Wróbel 《Acta Mathematica Hungarica》2009,124(4):333-351
Imaginary powers associated to the Laguerre differential operator $
L_\alpha = - \Delta + |x|^2 + \sum _{i = 1}^d \frac{1}
{{x_i^2 }}(\alpha _i^2 - 1/4)
$
L_\alpha = - \Delta + |x|^2 + \sum _{i = 1}^d \frac{1}
{{x_i^2 }}(\alpha _i^2 - 1/4)
are investigated. It is proved that for every multi-index α = (α1,...α
d
) such that α
i
≧ −1/2, α
i
∉ (−1/2, 1/2), the imaginary powers $
\mathcal{L}_\alpha ^{ - i\gamma } ,\gamma \in \mathbb{R}
$
\mathcal{L}_\alpha ^{ - i\gamma } ,\gamma \in \mathbb{R}
, of a self-adjoint extension of L
α, are Calderón-Zygmund operators. Consequently, mapping properties of $
\mathcal{L}_\alpha ^{ - i\gamma }
$
\mathcal{L}_\alpha ^{ - i\gamma }
follow by the general theory. 相似文献
15.
S. R. Hayrapetyan 《Journal of Contemporary Mathematical Analysis (Armenian Academy of Sciences)》2010,45(4):221-238
The paper considers a class of regular, hypoelliptic in x
1, two-dimensional operators P(D) = P(D
1,D
2) in rather wide strip Ω
H
= {x = (x
1; x
2) ∈ $
\mathbb{E}
$
\mathbb{E}
2, |x
1| < H, x
2 ∈ $
\mathbb{E}
$
\mathbb{E}
1}. It is proved the infinite differentiability in Ω
H
of those generalized solutions of the equation P(D)
u
= 0, for which D
2
j
u ∈ L
2(Ω
H
), j = 0, …, ord
x2
P. 相似文献
16.
In this article we investigate Vranceanu rotation surfaces with pointwise 1- type Gauss map in Euclidean 4-space $
\mathbb{E}^4
$
\mathbb{E}^4
. We show that a Vranceanu rotation surface M has harmonic Gauss map if and only if M is a part of a plane. Further, we give necessary and sufficent conditions for Vranceanu rotation surface to have pointwise
1-type Gauss map. 相似文献
17.
M. V. Deikalova 《Proceedings of the Steklov Institute of Mathematics》2009,266(Z1):129-142
The best constant C
n,m
in the Jackson-Nikol’skii inequality between the uniform and integral norms of algebraic polynomials of a given total degree
n ≥ 0 on the unit sphere $
\mathbb{S}^{m - 1}
$
\mathbb{S}^{m - 1}
of the Euclidean space ℝ
m
is studied. Two-sided estimates for the constant C
n,m
are obtained, which, in particular, give the order n
m−1 of its behavior with respect to n as n → +∞ for a fixed m. 相似文献
18.
Viorel Vâjâitu 《Czechoslovak Mathematical Journal》2010,60(3):655-667
Let X be a complex space of dimension n, not necessarily reduced, whose cohomology groups H
1(X, $
\mathcal{O}
$
\mathcal{O}
), ...,H
n−1(X, $
\mathcal{O}
$
\mathcal{O}
) are of finite dimension (as complex vector spaces). We show that X is Stein (resp., 1-convex) if, and only if, X is holomorphically
spreadable (resp., X is holomorphically spreadable at infinity). 相似文献
19.
Bang-Yen Chen 《Archiv der Mathematik》2010,94(3):291-299
It is well known that there are no minimal surfaces of constant curvature lying fully in the hyperbolic 4-space H
4(−1). In contrast, in this article we discover a minimal immersion of the hyperbolic plane
H2(-\frac13){H^2(-\frac{1}{3})} of curvature
-\frac13{-\frac{1}{3}} into the neutral pseudo-hyperbolic 4-space H42(-1){H^4_2(-1)}. Moreover, we prove that, up to rigid motions of H42(-1){H^4_2(-1)}, this minimal immersion provides the only space-like parallel minimal surface lying fully in H42(-1){H^4_2(-1)}. 相似文献
20.
In this article we extend the notion of constant angle surfaces in $
\mathbb{S}^2
$
\mathbb{S}^2
× ℝ and ℍ2 × ℝ to general Bianchi-Cartan-Vranceanu spaces. We show that these surfaces have constant Gaussian curvature and we give
a complete local classification in the Heisenberg group. 相似文献
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