共查询到20条相似文献,搜索用时 15 毫秒
1.
I. N. Herstein 《Israel Journal of Mathematics》1977,26(2):205-208
The theorem which we shall prove here states that if a subring of a prime ring is invariant with respect to a certain class of automorphisms then a dichotomy of the Brauer-Cartan-Hua type exists. 相似文献
2.
On invariant additive subgroups 总被引:1,自引:0,他引:1
C. L. Chuang 《Israel Journal of Mathematics》1987,57(1):116-128
Suppose thatR is a prime ring with the centerZ and the extended centroidC. An additive subgroupA ofR is said to be invariant under special automorphisms if (1+t)A(1+t)−1 ⊆A for allt ∈R such thatt
2=0. Assume thatR possesses nontrivial idempotents. We prove: (1) If chR ≠ 2 or ifRC ≠C
2, then any noncentral additive subgroup ofR invariant under special automorphisms contains a noncentral Lie ideal. (2) If chR=2,RC=C
2 andC ≠ {0, 1}, then the following two conditions are equivalent: (i) any noncentral additive subgroup invariant under special
automorphisms contains a noncentral Lie ideal; (ii) there isα ∈Z / {0} such thatα
2
Z ⊆ {β
2:β ∈Z}. 相似文献
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Yair Glasner 《Israel Journal of Mathematics》2017,219(1):215-270
Let Γ < GL n (F) be a countable non-amenable linear group with a simple, center free Zariski closure. Let Sub(Γ) denote the space of all subgroups of Γ with the compact, metric, Chabauty topology. An invariant random subgroup (IRS) of Γ is a conjugation invariant Borel probability measure on Sub(Γ). An IRS is called non-trivial if it does not have an atom in the trivial group, i.e. if it is non-trivial almost surely. We denote by IRS0(Γ) the collection of all non-trivial IRS on Γ.
Theorem 0.1: With the above notation, there exists a free subgroup F < Γ and a non-discrete group topology on Γ such that for every μ ∈ IRS0(Γ) the following properties hold:
Φ: (Sub(Γ), μ) → (Sub(F),Φ*μ) Δ → Δ ∩ F is an F-invariant isomorphism of probability spaces.A more technical version of this theorem is valid for general countable linear groups. We say that an action of Γ on a probability space, by measure preserving transformations, is almost surely non-free (ASNF) if almost all point stabilizers are non-trivial.Corollary 0.2: Let Γ be as in the Theorem above. Then the product of finitely many ASNF Γ-spaces, with the diagonal Γ action, is ASNF.Corollary 0.3: Let Γ < GLn(F) be a countable linear group, A Δ Γ the maximal normal amenable subgroup of Γ — its amenable radical. If μ ∈ IRS(Γ) is supported on amenable subgroups of Γ, then in fact it is supported on Sub(A). In particular, if A(Γ) = <e> then Δ = <e>, μ almost surely. 相似文献
μ-almost every subgroup of Γ is open
- F ·Δ = Γ for μ-almost every Δ ∈ Sub(Γ).
- F ∩ Δ is infinitely generated, for every open subgroup. In particular, this holds for μ-almost every Δ ∈ Sub(Γ).
- The map
5.
Sandro Mattarei 《Israel Journal of Mathematics》2007,159(1):343-347
We describe the additive subgroups of fields which are closed with respect to taking inverses, in particular, with characteristic
different from two. Any such subgroup is either a subfield or the kernel of the trace map of a quadratic subextension of the
field.
Partially supported by MIUR-Italy via PRIN 2003018059 “Graded Lie algebras and pro-p-groups: representations, periodicity and derivations”. 相似文献
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C.R Putnam 《Journal of Functional Analysis》1974,17(3):263-273
Let T be a subnormal, nonnormal operator on a Hilbert space and suppose that the point spectrum of is empty. Then there exist vectors x ≠ 0 for which exists and is weakly continuous for all z. It is shown that under certain conditions, the Cauchy integral of this vector function taken around an appropriate contour, not necessarily lying in the resolvent set of , leads to a proper (nontrivial) invariant subspace of . 相似文献
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Janusz Grabowski 《Proceedings of the American Mathematical Society》1999,127(5):1563-1565
We prove that for a line-free closed additive subgroup of a Hilbert space certain orthogonal projections lead to coverings of this group. This makes it possible to obtain additive subgroups which are homotopically non-trivial.
12.
Consider the system
$
\dot x = A\left( \cdot \right)x + b_1 \left( \cdot \right)u_1 + b_2 \left( \cdot \right)u_2 + g\left( \cdot \right), x\left( 0 \right) = x0
$
\dot x = A\left( \cdot \right)x + b_1 \left( \cdot \right)u_1 + b_2 \left( \cdot \right)u_2 + g\left( \cdot \right), x\left( 0 \right) = x0
相似文献
13.
V. G. Bardakov 《Algebra and Logic》1997,36(5):288-301
We study into widths of verbal subgroups of HNN-extensions, and of groups with one defining relation. It is proved that if
a group G* is an HNN-extension and the connected subgroups in G* are distinct from a base of the extension, then every verbal subgroup V(G*) has infinite width relative to a finite proper set V of words. A similar statement is proven to hold for groups presented
by one defining relation and ≥3 generators.
to Yurii I. Merzlyakov dedicated
Supported by RFFR grant No. 93-01-01513.
Translated fromAlgebra i Logika, Vol. 36, No. 5, pp. 494–517, September–October, 1997. 相似文献
14.
G. Szegö 《Annali di Matematica Pura ed Applicata》1955,40(1):113-119
Summary A simple new method of symmetrization is defined and the change of various geometrical and physical quantities under this
transformation investigated.
To Mauro Picone on his 70th birthday. 相似文献
15.
In this paper, we extend central portions of the geometric invariant theory for reductive groups G to nonreductive subgroups H satisfying the codimension 2 condition on G/H. First, the separated orbits for such subgroups are described using a one-parameter subgroup criterion. Second, the desired theorems concerning quotient varieties for spaces of separated orbits are proved. 相似文献
16.
Frank W Schmidt 《Journal of Combinatorial Theory, Series A》1982,33(1):30-35
The density of sets not containing a diagonal, a special type of arithmetic progression, is investigated. A lower bound on this density is established which sharpens a result of Alspach, Brown, and Hell (J. London Math. Soc.13 (2) (1976), 226–334. 相似文献
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Hall subgroups of certain families of finite groups 总被引:2,自引:0,他引:2
Edward L. Spitznagel Jr. 《Mathematische Zeitschrift》1967,97(4):259-290
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