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1.
For many orbital measures μ, on SU(n), we show that either μk ∈ L2 or μk is singular to L1. The least k for which μk ∈ L2 is determined and is shown to be the minimum k for which the k-fold product of the conjugacy class supporting the measure has positive measure. It would be interesting to know if all orbital
measures satisfy this dichotomy. 相似文献
2.
In this paper a method for the resolution of the differential equation of the Jacobi vector fields in the manifold V
1 = Sp(2)/SU(2) is exposed. These results are applied to determine areas and volumes of geodesic spheres and balls.
Work partially supported by DGI (Spain) and FEDER Projects MTM 2004-06015-C02-01 and MTM 2007-65852 (first author) and by
Research Project PGIDIT05PXIB16601PR (second author).
Authors’ addresses: A. M. Naveira, Departamento de Geometría y Topología. Facultad de Matemáticas, Avda. Andrés Estellés,
N1, 46100 – Burjassot, Valencia, Spain; A. D. Tarrío Tobar, E. U. Arquitectura Técnica, Campus A Zapateira. Universidad de
A Coru?a, 15192 – A Coru?a, Spain 相似文献
3.
L. Olsen 《Monatshefte für Mathematik》2005,146(2):143-157
For a probability measure μ on a subset of
, the lower and upper Lq-dimensions of order
are defined by
We study the typical behaviour (in the sense of Baire’s category) of the Lq-dimensions
and
. We prove that a typical measure μ is as irregular as possible: for all q ≥ 1, the lower Lq-dimension
attains the smallest possible value and the upper Lq-dimension
attains the largest possible value. 相似文献
4.
Peter A. Lesky 《Monatshefte für Mathematik》2005,144(4):297-316
Characterization of q-Orthogonal Polynomials. Im Anschluß an die Arbeit Orthogonalpolynome in x und q–x als Lösungen von reellen q-Operatorgleichungen zweiter Ordnung (Monatsh. Math. 132, 123–140 (2001); im folgenden als [4] zitiert) werden alle Möglichkeiten für q-Orthogonalpolynome in x als Lösungen von q-Operatorgleichungen zweiter Ordnung angegeben (Orthogonalität im positiv definiten Sinne). Dabei erfolgt die Numerierung der Abschnitte und die Angabe der Formel-nummern unter Einbeziehung von [4]. 相似文献
5.
We construct a three-parameter family of contact metric structures on the unit tangent sphere bundle T
1
M of a Riemannian manifold M and we study some of their special properties related to the Levi-Civita connection. More precisely, we give the necessary
and sufficient conditions for a constructed contact metric structure to be K-contact, Sasakian, to satisfy some variational conditions or to define a strongly pseudo-convex CR-structure. The obtained
results generalize classical theorems on the standard contact metric structure of T
1
M.
Author supported by funds of the University of Lecce. 相似文献
6.
In [6], ?evik defined necessary and sufficient conditions for the presentation of a central extension of a cyclic group by
an ordinary group to be p-Cockcroft, where p is a prime or 0. In this paper, as a next step of this above result, we will define the p-Cockcroft property for the presentation of a central extension of an abelian group by any group. Finally, as an application
of the main result, we will present an example. 相似文献
7.
In this paper we consider two nonlinear elliptic problems driven by the p-Laplacian and having a nonsmooth potential (hemivariational inequalities). The first is an eigenvalue problem and we prove
that if the parameter λ < λ2 = the second eigenvalue of the p-Laplacian, then there exists a nontrivial smooth solution. The second problem is resonant both near zero and near infinity
for the principal eigenvalue of the p-Laplacian. For this problem we prove a multiplicity result. Our approach is variational based on the nonsmooth critical point
theory.
Second author is Corresponding author. 相似文献
8.
A Lower Bound for the Height of a Rational Function at <Emphasis Type="Italic">S</Emphasis>-unit Points 总被引:1,自引:1,他引:0
Let a,b be given, multiplicatively independent positive integers and let >0. In a recent paper jointly with Y. Bugeaud we proved the upper bound exp(n) for g.c.d.(an–1, bn–1); shortly afterwards we generalized this to the estimate g.c.d.(u–1,v–1)v) for multiplicatively independent S-units u,vZ. In a subsequent analysis of those results it turned out that a perhaps better formulation of them may be obtained in terms of the language of heights of algebraic numbers. In fact, the purposes of the present paper are: to generalize the upper bound for the g.c.d. to pairs of rational functions other than {u–1,v–1} and to extend the results to the realm of algebraic numbers, giving at the same time a new formulation of the bounds in terms of height functions and algebraic subgroups of Gm2. 相似文献
9.
Jeffrey D. Vaaler 《Monatshefte für Mathematik》2008,154(4):323-343
We prove an upper bound for the Mahler measure of the Wronskian of a collection of N linearly independent polynomials with complex coefficients. If the coefficients of the polynomials are algebraic numbers
we obtain an inequality for the absolute Weil heights of the roots of the polynomials. This later inequality is analogous
to the abc inequality for polynomials, and also has applications to Diophantine problems.
Research supported in part by the National Science Foundation (DMS-06-03282) and the Erwin Schr?dinger Institute.
Author’s address: Department of Mathematics, University of Texas, Austin, Texas 78712, USA 相似文献
10.
José Francisco Rodrigues Manel Sanchón José Miguel Urbano 《Monatshefte für Mathematik》2008,154(4):303-322
The aim of this paper is twofold: to prove, for L
1-data, the existence and uniqueness of an entropy solution to the obstacle problem for nonlinear elliptic equations with variable
growth, and to show some convergence and stability properties of the corresponding coincidence set. The latter follow from
extending the Lewy-Stampacchia inequalities to the general framework of L
1.
Current address: Manel Sanchón, Universitat de Barcelona, Departament de Matemàtica Aplicada i Anàlisi, Gran Via 585, 08007
Barcelona, Spain; e-mail: msanchon@maia.ub.es
Authors’ addresses: J. F. Rodrigues, CMUC, Department of Mathematics, University of Coimbra, and FCUL/Universidade de Lisboa,
Av. Prof. Gama Pinto 2, 1649-003 Lisboa, Portugal; M. Sanchón and J. M. Urbano, CMUC, Department of Mathematics, University
of Coimbra, 3001-454 Coimbra, Portugal 相似文献
11.
Finite groups G=AB factorized by two subgroups A and B such that every subgroup of A permutes with every subgroup of B are studied in this paper. The behaviour of such products with respect to the class of finite groups in which Sylow-permutability is transitive is analyzed. 相似文献
12.
Carlo Magagna 《Monatshefte für Mathematik》2008,153(1):59-81
For a positive integer N, we define the N-rank of a non singular integer d × d matrix A to be the maximum integer r such that there exists a minor of order r whose determinant is not divisible by N. Given a positive integer r, we study the growth of the minimum integer k, such that A
k
− I has N-rank at most r, as a function of N. We show that this integer k goes to infinity faster than log N if and only if for every eigenvalue λ which is not a root of unity, the sum of the dimensions of the eigenspaces relative
to eigenvalues which are multiplicatively dependent with λ and are not roots of unity, plus the dimensions of the eigenspaces
relative to eigenvalues which are roots of unity, does not exceed d − r − 1. This result will be applied to recover a recent theorem of Luca and Shparlinski [6] which states that the group of rational
points of an ordinary elliptic curve E over a finite field with q
n
elements is almost cyclic, in a sense to be defined, when n goes to infinity. We will also extend this result to the product of two elliptic curves over a finite field and show that
the orders of the groups of
rational points of two non isogenous elliptic curves are almost coprime when n approaches infinity.
Author’s address: Dipartimento di Matematica e Informatica, Via Delle Scienze 206, 33100 Udine, Italy 相似文献
13.
Marian Ioan Munteanu 《Monatshefte für Mathematik》2007,150(4):333-342
In this paper we study doubly warped product CR submanifolds in locally conformal K?hler manifolds, and we found a B.Y. Chen’s type inequality for the second fundamental
form of these submanifolds.
Beneficiary of a CNR-NATO Advanced Research Fellowship pos. 216.2167 Prot. n. 0015506. 相似文献
14.
15.
Let be a fixed point free group given by the presentation
where and are relative prime numbers, t = /s and s = gcd( – 1,), and is the order of modulo . We prove that if (1) = 2, and (2) is embeddable into the multiplicative group of some skew field, then is circular. This means that there is some additive group N on which acts fixed point freely, and |((a)+b)((c)+d)| 2 whenever a,b,c,d N, a0c, are such that (a)+b(c)+d. 相似文献
16.
For a finite group G, let E(G) denote the near-ring of functions generated by the semigroup, End(G), of endomorphisms of G. We characterize when E(G) is maximal as a subnear-ring of M
0(G). A group G is an E-group if E(G) is a ring. We give a new characterization of finite E-groups and investigate the problem of determining, for finite E-groups, when E(G) is maximal as a ring in M0(G).
Received: 26 June 2006 相似文献
17.
Pavel Shumyatsky 《Monatshefte für Mathematik》2005,146(1):77-82
The following theorem is proved. Let G be a finite group of odd order admitting an involutory automorphism φ. Suppose that G has derived length d and that CG(φ) is nilpotent of class c. Assume that CG(φ) is a m-generator. Then [G,φ]′ is nilpotent of {c,d,m}-bounded class. 相似文献
18.
Cindy De Volder 《Monatshefte für Mathematik》2004,143(1):61-80
We consider a rational surface Xr, obtained by blowing up 2 along a curvilinear zero-dimensional subscheme of length r of the regular locus of a reduced irreducible plane curve of degree d, with d 4; and we give sufficient conditions for d-standard classes to be very ample (resp. base point free or non special) on such a rational surface Xr.Postdoctoral Fellow of the Fund for Scientific Research-Flanders (Belgium). 相似文献
19.
Zhijian Qiu 《Integral Equations and Operator Theory》2007,59(2):223-244
Let K be a compact subset in the complex plane and let A(K) be the uniform closure of the functions continuous on K and analytic on K°. Let μ be a positive finite measure with its support contained in K. For 1 ≤ q < ∞, let Aq(K, μ) denote the closure of A(K) in Lq(μ). The aim of this work is to study the structure of the space Aq(K, μ). We seek a necessary and sufficient condition on K so that a Thomson-type structure theorem for Aq(K, μ) can be established. Our theorem deduces J. Thomson’s structure theorem for Pq(μ), the closure of polynomials in Lq(μ), as the special case when K is a closed disk containing the support of μ. 相似文献
20.
Winfried Kohnen 《Monatshefte für Mathematik》2004,143(2):163-167
We point out that the formalism of the trace map and reduction modulo p can be used to give a short proof for the fact first proved by Ogg that is not a Weierstrass point on X0(pM) where p is a prime not dividing M and the genus of X0(M) is zero. 相似文献