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2.
The (full) transformation semigroup Tn\mathcal{T}_{n} is the semigroup of all functions from the finite set {1,…, n} to itself, under the operation of composition. The symmetric group Sn í Tn{\mathcal{S}_{n}\subseteq \mathcal{T}_{n}} is the group of all permutations on {1,…, n} and is the group of units of Tn\mathcal{T}_{n}. The complement Tn\ Sn\mathcal{T}_{n}\setminus \mathcal{S}_{n} is a subsemigroup (indeed an ideal) of Tn\mathcal{T}_{n}. In this article we give a presentation, in terms of generators and relations, for Tn\ Sn\mathcal{T}_{n}\setminus \mathcal{S}_{n}, the so-called singular part of Tn\mathcal{T}_{n}. 相似文献
4.
A code C{{\mathcal C}} is
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-additive if the set of coordinates can be partitioned into two subsets X and Y such that the punctured code of C{{\mathcal C}} by deleting the coordinates outside X (respectively, Y) is a binary linear code (respectively, a quaternary linear code). The corresponding binary codes of
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-additive codes under an extended Gray map are called
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear codes. In this paper, the invariants for
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear codes, the rank and dimension of the kernel, are studied. Specifically, given the algebraic parameters of
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear codes, the possible values of these two invariants, giving lower and upper bounds, are established. For each possible
rank r between these bounds, the construction of a
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear code with rank r is given. Equivalently, for each possible dimension of the kernel k, the construction of a
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear code with dimension of the kernel k is given. Finally, the bounds on the rank, once the kernel dimension is fixed, are established and the construction of a
\mathbb Z2\mathbb Z4{{\mathbb{Z}_2\mathbb{Z}_4}}-linear code for each possible pair ( r, k) is given. 相似文献
5.
Let ${\mathcal {H}_{1}}Let H1{\mathcal {H}_{1}} and H2{\mathcal {H}_{2}} be separable Hilbert spaces, and let A ? B(H1), B ? B(H2){A \in \mathcal {B}(\mathcal {H}_{1}),\, B \in \mathcal {B}(\mathcal {H}_{2})} and C ? B(H2, H1){C \in \mathcal {B}(\mathcal {H}_{2},\, \mathcal {H}_{1})} be given operators. A necessary and sufficient condition is given for ${\left(\begin{smallmatrix}A &\enspace C\\ X &\enspace B \end{smallmatrix}\right)}${\left(\begin{smallmatrix}A &\enspace C\\ X &\enspace B \end{smallmatrix}\right)} to be a right (left) invertible operator for some X ? B(H1, H2){X \in \mathcal {B}(\mathcal {H}_{1},\, \mathcal {H}_{2})}. Furthermore, some related results are obtained. 相似文献
6.
Let V be a 2 m-dimensional symplectic vector space over an algebraically closed field K. Let $ \mathfrak{B}_n^{(f)} Let V be a 2m-dimensional symplectic vector space over an algebraically closed field K. Let
\mathfrakBn(f) \mathfrak{B}_n^{(f)} be the two-sided ideal of the Brauer algebra
\mathfrakBn( - 2m ) {\mathfrak{B}_n}\left( { - 2m} \right) over K generated by e
1
e
3⋯
e
2f-1 where 0 ≤ f ≤ [n/2]. Let HTf ?n \mathcal{H}\mathcal{T}_f^{ \otimes n} be the subspace of partial-harmonic tensors of valence f in V
⊗n
. In this paper we prove that dimHTf ?n \mathcal{H}\mathcal{T}_f^{ \otimes n} and dim
\textEn\textdK\textSp(V)( V ?n \mathord | / |
\vphantom V ?n V ?n V ?n\mathfrakBn(f) ) {\text{En}}{{\text{d}}_{K{\text{Sp}}(V)}}\left( {{{{V^{ \otimes n}}} \mathord{\left/{\vphantom {{{V^{ \otimes n}}} {{V^{ \otimes n}}}}} \right.} {{V^{ \otimes n}}}}\mathfrak{B}_n^{(f)}} \right) are both independent of K, and the natural homomorphism from
\mathfrakBn( - 2m ) \mathord | / |
\vphantom ( - 2m ) \mathfrakBn(f) \mathfrakBn(f) {\mathfrak{B}_n}{{\left( { - 2m} \right)} \mathord{\left/{\vphantom {{\left( { - 2m} \right)} {\mathfrak{B}_n^{(f)}}}} \right.} {\mathfrak{B}_n^{(f)}}} to
\textEn\textdK\textSp(V)( V ?n \mathord | / |
\vphantom V ?n V ?n V ?n\mathfrakBn(f) ) {\text{En}}{{\text{d}}_{K{\text{Sp}}(V)}}\left( {{{{V^{ \otimes n}}} \mathord{\left/{\vphantom {{{V^{ \otimes n}}} {{V^{ \otimes n}}}}} \right.} {{V^{ \otimes n}}}}\mathfrak{B}_n^{(f)}} \right) is always surjective. We show that HTf ?n \mathcal{H}\mathcal{T}_f^{ \otimes n} has a Weyl filtration and is isomorphic to the dual of
V ?n\mathfrakBn(f) \mathord | / |
\vphantom V ?n\mathfrakBn(f) V V ?n\mathfrakBn( f + 1 ) {{{{V^{ \otimes n}}\mathfrak{B}_n^{(f)}} \mathord{\left/{\vphantom {{{V^{ \otimes n}}\mathfrak{B}_n^{(f)}} V}} \right.} V}^{ \otimes n}}\mathfrak{B}_n^{\left( {f + 1} \right)} as an
\textSp(V) - ( \mathfrakBn( - 2m ) \mathord | / |
\vphantom ( - 2m ) \mathfrakBn( f + 1 ) \mathfrakBn( f + 1 ) ) {\text{Sp}}(V) - \left( {{\mathfrak{B}_n}{{\left( { - 2m} \right)} \mathord{\left/{\vphantom {{\left( { - 2m} \right)} {\mathfrak{B}_n^{\left( {f + 1} \right)}}}} \right.} {\mathfrak{B}_n^{\left( {f + 1} \right)}}}} \right) -bimodule. We obtain an
\textSp(V) - \mathfrakBn {\text{Sp}}(V) - {\mathfrak{B}_n} -bimodules filtration of V
⊗n
such that each successive quotient is isomorphic to some
?( l) ?zg,l\mathfrakBn \nabla \left( \lambda \right) \otimes {z_{g,\lambda }}{\mathfrak{B}_n} with λ ⊢ n 2g, ℓ(λ)≤m and 0 ≤ g ≤ [n/2], where ∇(λ) is the co-Weyl module associated to λ and z
g,λ is an explicitly constructed maximal vector of weight λ. As a byproduct, we show that each right
\mathfrakBn {\mathfrak{B}_n} -module
zg,l\mathfrakBn {z_{g,\lambda }}{\mathfrak{B}_n} is integrally defined and stable under base change. 相似文献
7.
Let X,X(1) ,X(2),... be independent identically distributed random variables with mean zero and a finite variance. Put S( n) = X(1) + ... + X( n), n = 1, 2,..., and define the Markov stopping time η
y
= inf { n ≥ 1: S( n) ≥ y} of the first crossing a level y ≥ 0 by the random walk S( n), n = 1, 2,.... In the case $
\mathbb{E}
$
\mathbb{E}
| X| 3 < ∞, the following relation was obtained in [8]: $
\mathbb{P}\left( {\eta _0 = n} \right) = \frac{1}
{{n\sqrt n }}\left( {R + \nu _n + o\left( 1 \right)} \right)
$
\mathbb{P}\left( {\eta _0 = n} \right) = \frac{1}
{{n\sqrt n }}\left( {R + \nu _n + o\left( 1 \right)} \right)
as n → ∞, where the constant R and the bounded sequence ν
n
were calculated in an explicit form. Moreover, there were obtained necessary and sufficient conditions for the limit existence
$
H\left( y \right): = \mathop {\lim }\limits_{n \to \infty } n^{{3 \mathord{\left/
{\vphantom {3 2}} \right.
\kern-\nulldelimiterspace} 2}} \mathbb{P}\left( {\eta _y = n} \right)
$
H\left( y \right): = \mathop {\lim }\limits_{n \to \infty } n^{{3 \mathord{\left/
{\vphantom {3 2}} \right.
\kern-\nulldelimiterspace} 2}} \mathbb{P}\left( {\eta _y = n} \right)
for every fixed y ≥ 0, and there was found a representation for H( y). The present paper was motivated by the following reason. In [8], the authors unfortunately did not cite papers [1, 5] where
the above-mentioned relations were obtained under weaker restrictions. Namely, it was proved in [5] the existence of the limit
$
\mathop {\lim }\limits_{n \to \infty } n^{{3 \mathord{\left/
{\vphantom {3 2}} \right.
\kern-\nulldelimiterspace} 2}} \mathbb{P}\left( {\eta _y = n} \right)
$
\mathop {\lim }\limits_{n \to \infty } n^{{3 \mathord{\left/
{\vphantom {3 2}} \right.
\kern-\nulldelimiterspace} 2}} \mathbb{P}\left( {\eta _y = n} \right)
for every fixed y ≥ 0 under the condition
$
\mathbb{E}
$
\mathbb{E}
X
2 < ∞ only; In [1], an explicit form of the limit $
\mathop {\lim }\limits_{n \to \infty } n^{{3 \mathord{\left/
{\vphantom {3 2}} \right.
\kern-\nulldelimiterspace} 2}} \mathbb{P}\left( {\eta _0 = n} \right)
$
\mathop {\lim }\limits_{n \to \infty } n^{{3 \mathord{\left/
{\vphantom {3 2}} \right.
\kern-\nulldelimiterspace} 2}} \mathbb{P}\left( {\eta _0 = n} \right)
was found under the same condition
$
\mathbb{E}
$
\mathbb{E}
X
2 < ∞ in the case when the summand X has an arithmetic distribution. In the present paper, we prove that the main assertion in [5] fails and we correct the original proof. It worth noting that
this corrected version was formulated in [8] as a conjecture. 相似文献
8.
Let f( n) be a strongly additive complex-valued arithmetic function. Under mild conditions on f, we prove the following weighted strong law of large numbers: if X,X
1, X
2, … is any sequence of integrable i.i.d. random variables, then
$
\mathop {\lim }\limits_{N \to \infty } \frac{{\sum\nolimits_{n = 1}^N {f(n)X_n } }}
{{\sum\nolimits_{n = 1}^N {f(n)} }} = \mathbb{E}Xa.s.
$
\mathop {\lim }\limits_{N \to \infty } \frac{{\sum\nolimits_{n = 1}^N {f(n)X_n } }}
{{\sum\nolimits_{n = 1}^N {f(n)} }} = \mathbb{E}Xa.s.
相似文献
10.
In this paper we apply the method of potentials for studying the Dirichlet and Neumann boundary-value problems for a B-elliptic equation in the form
$
\Delta _{x'} u + B_{x_{p - 1} } u + x_p^{ - \alpha } \frac{\partial }
{{\partial x_p }}\left( {x_p^\alpha \frac{{\partial u}}
{{\partial x_p }}} \right) = 0
$
\Delta _{x'} u + B_{x_{p - 1} } u + x_p^{ - \alpha } \frac{\partial }
{{\partial x_p }}\left( {x_p^\alpha \frac{{\partial u}}
{{\partial x_p }}} \right) = 0
相似文献
11.
Several authors have studied the filtered colimit closure
\varinjlim B\varinjlim\mathcal{B} of a class B\mathcal{B} of finitely presented modules. Lenzing called
\varinjlim B\varinjlim\mathcal{B} the category of modules with support in B\mathcal{B}, and proved that it is equivalent to the category of flat objects in the functor category ( Bop, Ab)(\mathcal{B}^\mathrm{op},\mathsf{Ab}). In this paper, we study the category ( Mod- R) B({\mathsf{Mod}\textnormal{-}R})^{\mathcal{B}} of modules with cosupport in B\mathcal{B}. We show that ( Mod- R) B({\mathsf{Mod}\textnormal{-}R})^{\mathcal{B}} is equivalent to the category of injective objects in ( B, Ab)(\mathcal{B},\mathsf{Ab}), and thus recover a classical result by Jensen-Lenzing on pure injective modules. Works of Angeleri-Hügel, Enochs, Krause,
Rada, and Saorín make it easy to discuss covering and enveloping properties of ( Mod- R) B({\mathsf{Mod}\textnormal{-}R})^{\mathcal{B}}, and furthermore we compare the naturally associated notions of B\mathcal{B}-coherence and B\mathcal{B}-noetherianness. Finally, we prove a number of stability results for
\varinjlim B\varinjlim\mathcal{B} and ( Mod- R) B({\mathsf{Mod}\textnormal{-}R})^{\mathcal{B}}. Our applications include a generalization of a result by Gruson-Jensen and Enochs on pure injective envelopes of flat modules. 相似文献
12.
This paper is devoted to studying the initial value problems of the nonlinear Kaup Kupershmidt equations δu/δt + α1 uδ^2u/δx^2 + βδ^3u/δx^3 + γδ^5u/δx^5 = 0, (x,t)∈ E R^2, and δu/δt + α2 δu/δx δ^2u/δx^2 + βδ^3u/δx^3 + γδ^5u/δx^5 = 0, (x, t) ∈R^2. Several important Strichartz type estimates for the fundamental solution of the corresponding linear problem are established. Then we apply such estimates to prove the local and global existence of solutions for the initial value problems of the nonlinear Kaup- Kupershmidt equations. The results show that a local solution exists if the initial function u0(x) ∈ H^s(R), and s ≥ 5/4 for the first equation and s≥301/108 for the second equation. 相似文献
14.
Let {A, B} and {C, D} be diagonalizable pairs of order n, i.e., there exist invertible matrices P, Q and X, Ysuchthat A = P∧Q, B = PΩQ, C =XГY, D= X△Y, where ∧ = diag(α1, α2, …, αn), Ω= diag(βl, β2, …βn), Г=diag(γ1,γ2,…,γn), △=diag(δl,δ2,…,δn). Let ρ((α,β), (γ,δ))=|αδ-βγ|/√|α|^2+|β|^2√|γ|^2+|δ|^2.In this paper, it will be proved that there is a permutation τ of {1,2,... ,n} such that n∑i=1[ρ((αi,βi),(γτ(i),δτ(i)))]^2≤n[1-1/κ^2(Y)κ^2(Q)(1-d2F(Z,W)/n)], where κ(Y) = ||Y||2||Y^-1||2,Z= (A,B),W= (C, D) and dF(Z,W) = 1/√2||Pz* -Pw*||F. 相似文献
16.
Let Ω
i
and Ω
o
be two bounded open subsets of
\mathbb Rn{{\mathbb{R}}^{n}} containing 0. Let G
i
be a (nonlinear) map from
?W i×\mathbb Rn{\partial\Omega^{i}\times {\mathbb{R}}^{n}} to
\mathbb Rn{{\mathbb{R}}^{n}} . Let a
o
be a map from ∂Ω
o
to the set
Mn(\mathbb R){M_{n}({\mathbb{R}})} of n × n matrices with real entries. Let g be a function from ∂Ω
o
to
\mathbb Rn{{\mathbb{R}}^{n}} . Let γ be a positive valued function defined on a right neighborhood of 0 in the real line. Let T be a map from
]1-(2/ n),+¥[× Mn(\mathbb R){]1-(2/n),+\infty[\times M_{n}({\mathbb{R}})} to
Mn(\mathbb R){M_{n}({\mathbb{R}})} . Then we consider the problem
$\left\{ {ll} {{\rm div}}\, (T(\omega,Du))=0 &\quad {{\rm in}} \;\Omega^{o} \setminus\epsilon{{\rm cl}} \Omega^{i},\\ -T(\omega,Du(x))\nu_{\epsilon\Omega^{i}}(x)=\frac{1}{\gamma(\epsilon)}G^{i}({x}/{\epsilon}, \gamma(\epsilon)\epsilon^{-1} ({\rm log} \, \epsilon)^{-\delta_{2,n}} u(x)) & \quad \forall x \in \epsilon\partial\Omega^{i},\\ T(\omega, Du(x)) \nu^{o}(x)=a^{o}(x)u(x)+g(x) & \quad \forall x \in \partial \Omega^{o}, \right.$\left\{ \begin{array}{ll} {{\rm div}}\, (T(\omega,Du))=0 &\quad {{\rm in}} \;\Omega^{o} \setminus\epsilon{{\rm cl}} \Omega^{i},\\ -T(\omega,Du(x))\nu_{\epsilon\Omega^{i}}(x)=\frac{1}{\gamma(\epsilon)}G^{i}({x}/{\epsilon}, \gamma(\epsilon)\epsilon^{-1} ({\rm log} \, \epsilon)^{-\delta_{2,n}} u(x)) & \quad \forall x \in \epsilon\partial\Omega^{i},\\ T(\omega, Du(x)) \nu^{o}(x)=a^{o}(x)u(x)+g(x) & \quad \forall x \in \partial \Omega^{o}, \end{array} \right. 相似文献
17.
A map T: X→X on a normed linear space is called nonexpansive if ‖ Tx-Ty‖≤‖ x-y‖∀ x, y∈ X. Let (Ω, Σ, P) be a probability space,
an increasing chain of σ-fields spanning Σ, X a Banach space, and T: X→X. A sequence (x n) of strongly
-measurable and strongly P-integrable functions on Ω taking on values in X is called a T- martingale if
.
Let T: H→H be a nonexpansive mapping on a Hilbert space H and let (x n) be a T-martingale taking on values in H. If
then x
n
/ n converges a.e.
Let T: X→X be a nonexpansive mapping on a p-uniformly smooth Banach space X, 1<p≤2, and let (x n) be a T-martingale (taking on values in X). If
then there exists a continuous linear functional f∈X
* of norm 1 such that
If, in addition, the space X is strictly convex, x
n
/ n converges weakly; and if the norm of X
* is Fréchet differentiable (away from zero), x
n
/ n converges strongly.
This work was supported by National Science Foundation Grant MCS-82-02093 相似文献
18.
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
19.
In this paper, we consider the Schrödinger type operator ${H = (-\Delta _{\mathbb {H}}^n)^2 +V ^{2}}In this paper, we consider the Schr?dinger type operator
H = (-D\mathbb Hn)2 +V 2{H = (-\Delta _{\mathbb {H}}^n)^2 +V ^{2}}, where the nonnegative potential V belongs to the reverse H?lder class
Bq1 for q1 3 \frac Q 2,Q 3 6{B_{{q}_{1}}\, {\rm for}\, q_{1}\geq {\frac {Q}{ 2}},Q \geq 6}, and
D\mathbb Hn{\Delta_{\mathbb {H}^n}} is the sublaplacian on the Heisenberg group
\mathbb Hn{\mathbb {H}^n}. An L
p
estimate and a weak type L
1 estimate for the operator
?4\mathbb Hn H-1{\nabla^4_{\mathbb {H}^n} H^{-1}} when V ? Bq1{V \in B_{{q}_{1}}} for
1 < p £ \fracq12{1 < p \leq \frac{q_{1}}{2}} are obtained. 相似文献
20.
Iterating the triple construction applied consecutively to n Boolean algebras, we introduce two finitely axiomatizable subclasses SAin{{\bf SA}^{\rm i}_n} and SAsn{{\bf SA}^{\rm s}_n} of the class SA
n
of all Stone algebras of degree n with all the structure homomorphisms in their P-product representation injective or surjective, respectively. Then the class
of all Post algebras of degree n is definitionally equivalent to the intersection SAin ? SAsn{{\bf SA}^{\rm i}_{n} \cap {\bf SA}^{\rm s}_{n}}. We show that for each n ≥ 2 the class SAin{{\bf SA}^{\rm i}_n} is hereditarily undecidable while SAsn{{\bf SA}^{\rm s}_{n}} is decidable. As a consequence we obtain several (un)decidability results for various axiomatic classes of Stone algebras:
among them the decidability of the class of all Stone algebras of degree n which are dually pseudocomplemented and form a dual Stone algebra under the operation of dual pseudocomplement, and undecidability
of the class of all Stone algebras with Boolean dense set. On the other hand, the class of all finite members in SA
n
is decidable. 相似文献
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