共查询到20条相似文献,搜索用时 15 毫秒
1.
Archiv der Mathematik - We study the class $$\mathcal {M}_p$$ of Schur multipliers on the Schatten-von Neumann class $$\mathcal {S}_p$$ with $$1 \le p \le \infty $$ as well as the class of... 相似文献
2.
We propose a generalisation of the congruence subgroup problem for groups acting on rooted trees. Instead of only comparing the profinite completion to that given by level stabilizers, we also compare pro-
$$\mathcal {C}$$
completions of the group, where
$$\mathcal {C}$$
is a pseudo-variety of finite groups. A group acting on a rooted, locally finite tree has the
$$\mathcal {C}$$
-congruence subgroup property (
$$\mathcal {C}$$
-CSP) if its pro-
$$\mathcal {C}$$
completion coincides with the completion with respect to level stabilizers. We give a sufficient condition for a weakly regular branch group to have the
$$\mathcal {C}$$
-CSP. In the case where
$$\mathcal {C}$$
is also closed under extensions (for instance the class of all finite p-groups for some prime p), our sufficient condition is also necessary. We apply the criterion to show that the Basilica group and the GGS-groups with constant defining vector (odd prime relatives of the Basilica group) have the p-CSP. 相似文献
3.
Mathematical Programming - Given two matroids $$\mathcal {M}_{1} = (E, \mathcal {B}_{1})$$ and $$\mathcal {M}_{2} = (E, \mathcal {B}_{2})$$ on a common ground set E with base sets $$\mathcal... 相似文献
4.
Brenda J. Latka 《Order》2003,20(2):109-119
Tournament embedding is an order relation on the class of finite tournaments. An antichain is a set of finite tournaments
that are pairwise incomparable in this ordering. We say an antichain
can be extended to an antichain
. Those finite antichains that can not be extended to antichains of arbitrarily large finite cardinality are exactly those
that contain a member of each of four families of tournaments. We give an upper bound on the cardinality of extensions of
such antichains. This bound depends on the maximum order of the tournaments in the antichain.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
5.
Jorge Antezana Gustavo Corach Demetrio Stojanoff 《Integral Equations and Operator Theory》2006,55(2):169-188
If
$$\mathcal{H}$$ is a Hilbert space,
$$\mathcal{S}$$ is a closed subspace of
$$\mathcal{H},$$ and A is a positive bounded linear operator on
$$\mathcal{H},$$ the spectral shorted operator
$$\rho \left( {\mathcal{S},\mathcal{A}} \right)$$ is defined as the infimum of the sequence
$$\sum (\mathcal{S},A^n )^{1/n} ,$$ where denotes
$$\sum \left( {\mathcal{S},B} \right)$$ the shorted operator of B to
$$\mathcal{S}.$$ We characterize the left spectral resolution of
$$\rho \left( {\mathcal{S},\mathcal{A}} \right)$$ and show several properties of this operator, particularly in the case that
dim
$${\mathcal{S} = 1.}$$ We use these results to generalize the concept of Kolmogorov complexity for the infinite dimensional
case and for non invertible operators. 相似文献
6.
Simon M. Goberstein 《Algebra Universalis》2005,53(4):407-432
A partial automorphism of a semigroup S is any isomorphism between its subsemigroups, and the set all partial automorphisms of S with respect to composition is an inverse monoid called the partial automorphism monoid of S. Two semigroups are said to be
if their partial automorphism monoids are isomorphic. A class
of semigroups is called
if it contains every semigroup
to some semigroup from
Although the class of all inverse semigroups is not
we prove that the class of inverse semigroups, in which no maximal isolated subgroup is a direct product of an involution-free periodic group and the two-element cyclic group, is
It follows that the class of all combinatorial inverse semigroups (those with no nontrivial subgroups) is
A semigroup is called
if it is isomorphic or antiisomorphic to any semigroup that is
to it. We show that combinatorial inverse semigroups which are either shortly connected [5] or quasi-archimedean [10] are
To Ralph McKenzieReceived April 15, 2004; accepted in final form October 7, 2004. 相似文献
7.
Let $$\mathcal {A}$$ be a standard operator algebra on a Banach space $$\mathcal {X}$$ with $$ \dim \mathcal {X}\ge 3$$. In this paper, we determine the form of the bijective maps $$\phi :\mathcal {A}\longrightarrow \mathcal {A}$$ satisfying $$\begin{aligned} \phi \left( \frac{1}{2}(AB^2+B^2A)\right) = \frac{1}{2}[\phi (A)\phi (B)^{2}+\phi (B)^{2}\phi (A)], \end{aligned}$$for every $$A,B \in \mathcal {A}$$. 相似文献
8.
In the solution of the monotone variational inequality problem VI(, F), with
the augmented Lagrangian method (a decomposition method) is advantageous and effective when
. For some problems of interest, where both the constraint sets
and
are proper subsets in
and
, the original augmented Lagrangian method is no longer applicable. For this class of variational inequality problems, we introduce a decomposition method and prove its convergence. Promising numerical results are presented, indicating the effectiveness of the proposed method. 相似文献
9.
Periodica Mathematica Hungarica - Let $$\mathcal {A}$$ be a von Neumann algebra acting on the complex Hilbert space $$\mathcal {H}$$ and $$\Phi {:}\,\mathcal {A} \longrightarrow \mathcal {A}$$ be a... 相似文献
10.
Adam Ose̦kowski 《Mediterranean Journal of Mathematics》2013,10(4):1883-1894
We establish a class of sharp logarithmic estimates for the Beurling-Ahlfors transform B on the complex plane. For any K > 0 we determine the optimal constant ${L = L(K) \in (0, \infty]}$ such that the following holds. If ${F : \mathbb{C} \rightarrow \mathbb{C}}$ is a radial function, then for any R > 0, $$\frac{1}{|\mathcal{B}(0, R)|} \int_{\mathcal{B}(0, R)} |BF(z)| dz \leq \frac{K}{|\mathcal{B}(0, R)|} \int_{\mathcal{B}(0, R)} \Psi(|F(z)|) dz + L(K),$$ where Ψ(t) = (t + 1) log(t + 1) – t and ${\mathcal{B}(0, R) \subset \mathbb{C}}$ denotes the ball of center 0 and radius R. A related result in higher dimensions is also established. The proof rests on probabilistic methods and exploits a certain sharp inequality for martingales. 相似文献
11.
Acta Mathematica Hungarica - Let $$\mathcal{X}$$ be a complex Banach space with $$\dim \mathcal{X}\geq 2$$ , and $$\mathcal{A} \subseteq \mathcal{B}(\mathcal{X})$$ be a standard operator algebra.... 相似文献
12.
We study the spectral problem $$\left. {\Delta \mathcal{U} + K^2 \mathcal{U} = 0, \frac{{\partial u}}{{\partial n}} - iK\mathcal{O}\mathcal{U}} \right|_{\partial \Omega } = 0, \mathfrak{S} \geqslant 0$$ We construct a self-adjoint dilatation and the problem is reduced to the investigation of a dissipative operator in a space with energy metric. 相似文献
13.
The aim of the present paper is to introduce a metric locally convex topology on the space
of δ-psh functions in the Cegrell class
. We prove that with this topology
is a non-separable and non-reflexive Fréchet space. At the same time, we extend the Monge–Ampère operator from the class
to
. 相似文献
14.
The Liouville-type theorem for problems with nonstandard growth derived by Caccioppoli-type estimate
Sylwia Dudek 《Monatshefte für Mathematik》2020,192(1):75-91
Let u be a nonnegative solution to the PDI $$-\,\mathrm{div} \mathcal {A}(x, u, \nabla u)\geqslant \mathcal {B}(x,u, \nabla u)$$ in $$\Omega $$, where $$\mathcal {A}$$ and $$\mathcal {B}$$ are differential operators with p(x)-type growth. As a consequence of the Caccioppoli-type inequality for the solution u, we obtain the Liouville-type theorem under some integral condition. We simplify the assumptions on functions $$ \mathcal {A}$$ and $$ \mathcal {B}$$, and we do not restrict the range of p(x) by the dimension n, therefore we can cover quite general family of problems. 相似文献
15.
T. V. Karataeva 《Ukrainian Mathematical Journal》1995,47(3):504-508
We obtain sufficient conditions of existence of the Stieltjes integral $$\int\limits_s^t {f(\tau )} d\mathcal{F}(\tau ) = \mathop {\lim }\limits_{\delta _n \to 0} \sum\limits_{k = 1}^{m_n } {f(\xi _k )(\mathcal{F}(t_k^n ) - \mathcal{F}(t_{k - 1}^n ))}$$ for functions of bounded variation taking values in a Banach algebra with identity regardless of the choice of points ξk ε [tk?1, tk]. 相似文献
16.
Endre Szemerédi 《Foundations of Computational Mathematics》2016,16(6):1737-1749
We discuss results obtained jointly with Van Vu on the length of arithmetic progressions in \(\ell \)-fold sumsets of the form and where \(\mathcal {A}\) is a set of integers. Applications are also discussed.
相似文献
$$\begin{aligned} \ell \mathcal {A}=\{a_1+\dots +a_\ell ~|~a_i\in \mathcal {A}\} \end{aligned}$$
$$\begin{aligned} \ell \mathcal {A}=\{a_1+\dots +a_\ell ~|~a_i\in \mathcal {A}\text { all distinct}\}, \end{aligned}$$
17.
The aim of this paper is to introduce a group containing the mapping class groups of all genus zero surfaces. Roughly speaking, such a group is intended to be a discrete analogue of the diffeomorphism group of the circle. One defines indeed a universal mapping class group of genus zero, denoted
The latter is a nontrivial extension of the Thompson group V (acting on the Cantor set) by an inductive limit of pure mapping class groups of all genus zero surfaces. We prove that
is a finitely presented group, and give an explicit presentation of it. 相似文献
18.
本文研究了单位圆盘上从$L^{\infty}(\mathbb{D})$空间到Bloch型空间 $\mathcal{B}_\alpha$ 一类奇异积分算子$Q_\alpha, \alpha>0$的范数, 该算子可以看成投影算子$P$ 的推广,定义如下$$Q_\alpha f(z)=\alpha \int_{\mathbb{D}}\frac{f(w)}{(1-z\bar{w})^{\alpha+1}}\d A(w),$$ 同时我们也得到了该算子从 $C(\overline{\mathbb{D}})$空间到小Bloch型空间$\mathcal{B}_{\alpha,0}$上的范数. 相似文献
19.
Periodica Mathematica Hungarica - Let $$\mathcal {A}$$ and $$\mathcal {B}$$ be abelian categories and $${\mathbf {F}} :\mathcal {A}\rightarrow \mathcal {B}$$ an additive and right exact functor... 相似文献
20.
Alexander J. Zaslavski 《Calculus of Variations and Partial Differential Equations》2007,28(3):351-381
In this paper we study nonoccurrence of the Lavrentiev phenomenon for a large class of nonconvex nonautonomous constrained
variational problems. A state variable belongs to a convex subset of a Banach space with nonempty interior. Integrands belong
to a complete metric space of functions
which satisfy a growth condition common in the literature and are Lipschitzian on bounded sets. In our previous work Zaslavski
(Ann. Inst. H. Poincare, Anal. non lineare, 2006) we considered a class of nonconstrained variational problems with integrands
belonging to a subset
and showed that for any such integrand the infimum on the full admissible class is equal to the infimum on a subclass of
Lipschitzian functions with the same Lipschitzian constant. In the present paper we show that if an integrand f belongs to
, then this property also holds for any integrand which is contained in a certain neighborhood of f in
. Using this result we establish nonoccurrence of the Lavrentiev phenomenon for most elements of
in the sense of Baire category.
相似文献