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1.
We consider actions of non-compact simple Lie groups preserving an analytic rigid geometric structure of algebraic type on a compact manifold. The structure is not assumed to be unimodular, so an invariant measure may not exist. Ergodic stationary measures always exist, and when such a measure has full support, we show the following:
1.  Either the manifold admits a smooth equivariant map onto a homogeneous projective variety, defined on an open dense conull invariant set, or the Lie algebra of the Zariski closure of the Gromov representation of the fundamental group contains a Lie subalgebra isomorphic to the Lie algebra of the acting group. As a corollary, a smooth non-trivial homogeneous projective factor does exist whenever the fundamental group of M admits only virtually solvable linear representations, and thus in particular when M is simply connected, regardless of the real rank.
2.  There exist explicit examples showing that analytic rigid actions of certain simple real rank one groups may indeed fail to have a smooth projective factor.
3.  It is possible to generalize Gromov’s theorem on the algebraic hull of the representation of the fundamental group of the manifold to the case of rigid non-unimodular structures, again for actions of groups of any real rank.
An important ingredient in the proofs is a generalization of Gromov’s centralizer theorem beyond the case of invariant measures.  相似文献   

2.
 In a recent paper [7] the author considered the family of parametrized Thue equations
for monic polynomials which satisfy
Under some technical conditions it could be proved that there is a computable constant such that for all integers the only integer solutions of the Diophantine equation satisfy . In this paper, we give an explicit expression for depending on the polynomials . (Received 5 September 2000; in revised form 30 December 2000)  相似文献   

3.
The Multiplier Theorem is a celebrated theorem in the Design theory. The conditionp>λ is crucial to all known proofs of the multiplier theorem. However in all known examples of difference sets μ p . is a multiplier for every primep with (p, v)=1 andpn. Thus there is the multiplier conjecture: “The multiplier theorem holds without the assumption thatp>λ”. The general form of the multiplier theorem may be viewed as an attempt to partially resolve the multiplier conjecture, where the assumption “p>λ” is replaced by “n 1>λ”. Since then Newman (1963), Turyn (1964), and McFarland (1970) attempted to partially resolve the multiplier conjecture (see [7], [8], [9]). This paper will prove the following result using the representation theory of finite groups and the algebraic number theory: LetG be an abelian group of orderv,v 0 be the exponent ofG, andD be a (v, k, λ)-difference set inG. Ifn=2n 1, then the general form of the multiplier theorem holds without the assumption thatn 1>λ in any of the following cases:
2〈  n 1;
2 Xn 1 and (v, 7)=1;
2 Xn1, 7〈  v, andt≡1 or 2 or 4 (mod 7).
Supported by the scientific research finances of Peking University.  相似文献   

4.
In this paper, we prove that for a sublinear expectation ɛ[·] defined on L 2(Ω,), the following statements are equivalent:
(i)  ɛ is a minimal member of the set of all sublinear expectations defined on L 2(Ω,)
(ii)  ɛ is linear
(iii)  the two-dimensional Jensen’s inequality for ɛ holds.
Furthermore, we prove a sandwich theorem for subadditive expectation and superadditive expectation. This work was supported by National Basic Research Program of China (973 Program) (Grant No. 2007CB814901) (Financial Risk) and National Natural Science Foundation of China (Grant No. 10671111)  相似文献   

5.
In a joint work with Saji, the second and the third authors gave an intrinsic formulation of wave fronts and proved a realization theorem for wave fronts in space forms. As an application, we show that the following four objects are essentially the same:
–  conformally flat n-manifolds (n ≥ 3) with admissible singular points (i.e. admissible GCF-manifolds)  相似文献   

6.
Let (G, τ) be a commutative Hausdorff locally solid lattice group. In this paper we prove the following:
(1)  If (G, τ) has the A(iii)-property, then its completion is an order-complete locally solid lattice group.
(2)  If G is order-complete and τ has the Fatou property, then the order intervals of G are τ-complete.
(3)  If (G, τ) has the Fatou property, then G is order-dense in Ĝ and has the Fatou property.
(4)  The order-bound topology on any commutative lattice group is the finest locally solid topology on it.
As an application, a version of the Nikodym boundedness theorem for set functions with values in a class of locally solid topological groups is established.  相似文献   

7.
8.
A theorem of Fejér states that if a periodic function F is of bounded variation on the closed interval [0, 2π], then the nth partial sum of its formally differentiated Fourier series divided by n converges to π-1[F(x+0)-F(x-0)] at each point x. The generalization of this theorem for Fourier-Stieltjes series of (nonperiodic) functions of bounded variation is also well known. The aim of the present article is to extend these results to the (m, n)th rectangular partial sum of double Fourier or Fourier-Stieltjes series of a function F(x, y) of bounded variation over the closed square [0, 2π]×[0, 2π] in the sense of Hardy and Krause. As corollaries, we also obtain the following results:
(i)  The terms of the Fourier or Fourier-Stieltjes series of F(x, y) determine the atoms of the (periodic) Borel measure induced by (an appropriate extension of) F.
(ii)  In the case of periodic functions F(x, y) of bounded variation, the class of double Fourier-Stieltjes series coincides with the class of series that can be obtained from their Fourier series by a formal termwise differentiation with respect to both x and y.
  相似文献   

9.
In this paper, we solve a family of Diophantine equations associated with families of number fields of degree 3. In fact, we use Baker’s method find all solutions to the Thue equation
. The author was supported partially by Purdue University North Central.  相似文献   

10.
In the present paper, we prove an analog of Khinchin's metric theorem in the case of linear Diophantine approximations of plane curves defined over the ring of $p$ -adic integers by means of (Mahler) normal functions. We also prove some general assertions needed to generalize this result to the case of spaces of higher dimension.  相似文献   

11.
Consider the two natural representations of the symmetric groupS n on the group algebra ℂ[S n ]: the regular representation and the conjugacy representation (acting on the basis by conjugation). Letm(λ) be the multiplicity of the irreducible representationS λ in the conjugacy representation and letf λ be the multiplicity ofS λ in the regular representation. By the character estimates of [R1] and [Wa] we prove
(1)  For any 1>ε>0 there exist 0<δ(ε) andN(ε) such that, for any partitionλ ofn>N(ε) with max ,
whereλ 1 is the size of the largest part inλ andλ1 is the number of parts inλ.
(2)  For any fixed 1>r>0 and ε>0 there existκ=κ(ε, r) andN(ε, r) such that, for any partitionλ ofn>N(ε, r) with max ,
whereA is a constant which depends only on the fractions
This strengthens Adin-Frumkin’s result [AF] and answers a question of Stanley [St].
Partially sponsored by a Wolfson fellowship and the Hebrew University of Jerusalem.  相似文献   

12.
Consider the equation
((1))
withf, g continuous and h>0. By employing Liapunov's direct method, we construct an invariant sector in the phase space for certain solution maps and then show the existence of a nonconstant periodic solution of (1) using a fixed point theorem of Nussbaum with certain bifurcation techniques.  相似文献   

13.
This paper introduces the concept of orthogonal vector measures, and gives the Yosida-Hewittdecomposition theorem for this kind of vector measures. The major results are(a) Any orthogonal vector measure can gain it countable additivity by enlarging its domain;(b) Every orthogonal vector measure can be represented as the sum of two orthogonal vectormeasures, one of which is countably additive, and the other is purely finitely additive. Furthermore,these vector measures are completely perpendicular to each other.  相似文献   

14.
We develop the theory of “branch algebras”, which are infinite-dimensional associative algebras that are isomorphic, up to taking subrings of finite codimension, to a matrix ring over themselves. The main examples come from groups acting on trees. In particular, for every field % MathType!End!2!1! we contruct a % MathType!End!2!1! which
–  • is finitely generated and infinite-dimensional, but has only finitedimensional quotients;
–  • has a subalgebra of finite codimension, isomorphic toM 2(k);
–  • is prime;
–  • has quadratic growth, and therefore Gelfand-Kirillov dimension 2;
–  • is recursively presented;
–  • satisfies no identity;
–  • contains a transcendental, invertible element;
–  • is semiprimitive if % MathType!End!2!1! has characteristic ≠2;
–  • is graded if % MathType!End!2!1! has characteristic 2;
–  • is primitive if % MathType!End!2!1! is a non-algebraic extension of % MathType!End!2!1!;
–  • is graded nil and Jacobson radical if % MathType!End!2!1! is an algebraic extension of % MathType!End!2!1!.
The author acknowledges support from TU Graz and UC Berkeley, where part of this research was conducted.  相似文献   

15.
Summary.   We prove a functional central limit theorem for stationary random sequences given by the transformations
on the two-dimensional torus. This result is based on a functional central limit theorem for ergodic stationary martingale differences with values in a separable Hilbert space of square integrable functions. Received: 11 March 1997 / In revised form: 1 December 1997This research was supported by the Deutsche Forschungsgemeinschaft and the Russian Foundation for Basic Research, grant 96-01-00096. The second author was also partially supported by INTAS, grant 94-4194.  相似文献   

16.
Three series of number-theoretic problems with explicitly marked parameters that concerning systems of modulo m congruences and systems of Diophantine equations with solutions from the given segment are proposed. Parameter constraints such that any problem of each series is NP complete when they are met are proved. For any m1 and m2 (m1 < m2 and m1 is not a divisor of m2), the verification problem for the consistency of a system of linear congruences modulo m1 and m2 simultaneously, each containing exactly three variables, is proved to be NP complete. In addition, for any m > 2, the verification problem for the consistency on the subset, containing at least two elements, of the set {0, …, m–1} for the system of linear congruences modulo m, each of which contains exactly three variables, is proved to be NP complete. If P ≠ NP, one cannot replace the term 3-discongruence with the term 2-discongruence in the statement of the theorem. For systems of Diophantine linear equations, each of which contains exactly three variables, the verification problem for their consistency on the given segment of integers is proved to be NP complete. If P ≠ NP, one cannot replace the term 3-equation with the term 2-equation in the statement of the theorem. This problem can also have a simple geometrical interpretation concerning the NP completeness of the verification problem on whether there an integer point of intersection of the given hyperplanes exists that cuts off equivalent segments on three axes and are parallel to other axes inside of a multidimensional cube. The problems of the stated series include practically useful problems. Since the range of values for an integer computer variable can be considered integer values from a segment, if P ≠ NP, theorem 5 proves that any algorithm that solves these systems in the set of numbers of the integer type is nonpolynomial [6].  相似文献   

17.
It is shown that a non-degenerate curve in n satisfies a convergentGroshev theorem with a non-monotonic error function. In otherwords it is shown that if a volume sum converges the set ofpoints lying on the curve which satisfy a Diophantine conditionhas Lebesgue measure zero.  相似文献   

18.
We study several kinds of distributivity for concept lattices of contexts. In particular, we find necessary and sufficient conditions for a concept lattice to be
(1)  distributive,
(2)  a frame (locale, complete Heyting algebra),
(3)  isomorphic to a topology,
(4)  completely distributive,
(5)  superalgebraic (i.e., algebraic and completely distributive).
In cases (2), (4) and (5), our criteria are first order statements on objects and attributes of the given context. Several applications are obtained by considering the completion by cuts and the completion by lower ends of a quasiordered set as special types of concept lattices. Various degrees of distributivity for concept lattices are expressed by certain separation axioms for the underlying contexts. Passing to complementary contexts makes some statements and proofs more elegant. For example, it leads to a one-to-one correspondence between completely distributive lattices and so-called Cantor lattices, and it establishes an equivalence between partially ordered sets and doubly founded reduced contexts with distributive concept lattices.  相似文献   

19.
A family of transitive modular Lie superalgebras with depth one   总被引:1,自引:0,他引:1  
The embedding theorem is established for Z-graded transitive modular Lie superalgebras g=(?)satisfying the conditions: (i)g0(?)(g-1)and g0-module g-1 is isomorphic to the natural(?)(g-1)-module; (ii)dim g1=2/3n(2n~2 1),where n=1/2dim g-1. In particular,it is proved that the finite-dimensional simple modular Lie superalgebras satisfying the conditions above are isomorphic to the odd Hamiltonian superalgebras.The restricted Lie superalgebras are also considered.  相似文献   

20.
We construct a self-avoiding process taking values in the finite Sierpinski gasket, and study its properties. We then study continuum limit processes that are suggested by the statistical mechanics of self-avoiding paths on the pre-Sierpinski gasket. We prove that there are three types of continuum limit processes according to the parameters defining the statistical mechanics of self-avoiding paths:
(i)  the self-avoiding process we construct in this paper;
(ii)  a deterministic motion along a Peano curve on the finite Sierpinski gasket;
(iii)  a deterministic motion along a line segment.
  相似文献   

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