共查询到20条相似文献,搜索用时 15 毫秒
1.
Krzysztof Pawałowski 《Mathematische Annalen》2008,341(4):845-858
We construct for the first time smooth circle actions on highly symmetric manifolds such as disks, spheres, and Euclidean
spaces which contain two points with the same isotropy subgroup whose representations determined on the tangent spaces at
the two points are not isomorphic to each other. This allows us to answer negatively a question of Hsiang and Hsiang [Some
Problems in Differentiable Transformation Groups, Springer, Berlin, Problem 16, p. 228, 1968].
Dedicated to Prof. Yasuhiko Kitada on the occasion of his 60th birthday.
Krzysztof Pawałowski was supported in part by the KBN Research Grant N 201 008 31/0524. 相似文献
2.
Bruno Zimmermann 《Rendiconti del Circolo Matematico di Palermo》1999,48(3):549-562
We study arbitrary (that is not necessarily orientation preserving) finite group actions on 3-dimensional orientable or nonorientable
handlebodies of genus g. For g>1, the maximal possible order is 24(g−1); we characterize the corresponding groups of this
order and also the occuring quotient orbifolds. Then we use this to study finite group actions of large order (with respect
to the equivariant Heegaard genus g) on closed 3-manifolds, again concentrating on the maximal case of order 24(g−1). Our
results extend corresponding results in the orientation preserving setting. Whereas for arbitrary finite group actions on
handlebodies much more types of quotient orbifolds occur than in the orientation preserving case, it turns out that for closed
3-manifolds the situation is quite rigid, in contrast to the orientation preserving case where one has many possibilities
to construct manifolds with large group actions. 相似文献
3.
Larbi Berrahmoune 《Rendiconti del Circolo Matematico di Palermo》2005,54(2):273-290
This paper considers the problem of stabilization of linear control systems in Hilbert space with nonlinear feedback. Extensions
of known results in the linear feedback case to the nonlinear one are given. 相似文献
4.
5.
Peter B. Gilkey 《Journal of Geometric Analysis》1994,4(2):155-158
Osserman conjectured that if the curvature operatorR of a Riemannian manifoldM has constant eigenvalues, thenM is locally a rank-1 symmetric space or is flat. The pointwise question is considerably more complicated. We present examples
of Riemannian manifolds so thatR has constant eigenvalues at the basepoint, butR is not the curvature operator of a rank-1 symmetric space.
Research partially supported by the NSF and IHES. 相似文献
6.
Quo-Shin Chi 《Journal of Geometric Analysis》1991,1(4):373-382
It is proved that if the Besicovitch Covering Lemma is true on either a Hadamard manifold or a simply connected surface without
focal points that covers a compact quotient, then the manifold is the Euclidean space. As a corollary, the vanishing of the
topological entropy of a compact manifold of nonpositive curvature or of a compact surface without focal points is equivalent
to the validity of the Besicovitch Covering Lemma on the universal covering space of the manifold.
The author was partially supported by an NSF grant. 相似文献
7.
Peter Petersen 《Journal of Geometric Analysis》1991,1(4):383-387
It is proved that a Riemanniann-manifold with Ricci curvature ≥ (n − 1) and a lower injectivity radius bound is a sphere provided the diameter is sufficiently close to π.
The author was partially supported by the NSF and the Alfred P. Sloan Foundation. 相似文献
8.
Kenneth A. Brakke 《Journal of Geometric Analysis》1995,5(4):445-514
A new mathematical model of soap films is proposed, called the “covering space model.” The two sides of a film are modeled
as currents on different sheets of a covering space branching along the film boundary. Hence a film may be seen as the minimal
cut separating one sheet of the covering space from the others. The film is thus the oriented boundary of one sheet, which
represents the exterior of the film. As oriented boundaries, films may be calibrated with differential forms on the covering
space, a version of the min-cut, max-flow duality of network theory. This model applies to unoriented films, films with singularities,
films touching only part of a knotted curve, films that deformation retract to their boundaries, and other examples that have
proved troublesome for previous soap film models.
Communicated by Frederick Almgren 相似文献
9.
Michael Hutchings 《Journal of Geometric Analysis》1997,7(2):285-304
We show that the least area required to enclose two volumes in ℝn orS
n forn ≥ 3 is a strictly concave function of the two volumes. We deduce that minimal double bubbles in ℝn have no empty chambers, and we show that the enclosed regions are connected in some cases. We give consequences for the structure
of minimal double bubbles in ℝn. We also prove a general symmetry theorem for minimal enclosures ofm volumes in ℝn, based on an idea due to Brian White.
Supported in part by NSF DMS-9409166. 相似文献
10.
Jiaping Wang 《Journal of Geometric Analysis》1998,8(3):485-514
We consider the existence, uniqueness and convergence for the long time solution to the harmonic map heat equation between
two complete noncompact Riemannian manifolds, where the target manifold is assumed to have nonpositive curvature. As an application,
we solve the Dirichlet problem at infinity for proper harmonic maps between two hyperbolic manifolds for a class of boundary
maps. The boundary map under consideration has finite many points at which either it is not differentiable or has vanishing
energy density. 相似文献
11.
We consider in this paper interpolation problems for weighted spaces of entire and meromorphic functions. Various (analytic
and geometric) conditions necessary and sufficient for multiplicity varieties to be interpolating varieties will be given.
This research is supported in part by NSF Grants DMS-90-00616 and CDR 88-03012. 相似文献
12.
We construct examples of pairs of surfaces that share the same poles (with multiplicity) of the scattering operatorm, and
that are particularly simple in one or more senses. In particular, we find pairs of isoscattering surfaces of small genus
with a small number of ends. We also give examples of congruence surfaces which are isoscattering. 相似文献
13.
Mario Krnić Josip Pečarić Predrag Vuković 《Rendiconti del Circolo Matematico di Palermo》2007,56(3):349-357
In this paper we obtain an extension of discrete Hilbert’s inequality, by using some numerical methods. We shall obtain, in
a similar way as Yang did in [10], that the parameter from the kernel can be taken from the interval [3/2, 3). We also compare
our findings with existing results, known from the literature. 相似文献
14.
Maurizio Valsecchi 《Rendiconti del Circolo Matematico di Palermo》2004,53(1):129-152
We give the structure of finite groups belonging to some families defined by conditions of complementation.
The author was supported by Istituto Nazionale di Alta Matematica “Francesco Severi” - Rome. 相似文献
15.
We present a characterization of the open unit ball in a separable infinite dimensional Hilbert space by the property of automorphism
orbits among the domains that are not necessarily bounded. This generalizes the recent work of Kim and Krantz [6]. Key new
features of this article include: a lower bound estimate of the Kobayashi metric and distance near a pluri-subharmonic peak
boundary point of the domains in Banach spaces, an effective localization argument, and an improvement of weak-type convergence
of sequences of biholomorphic mappings of domains in Banach spaces. 相似文献
16.
Baouendi M. S. Mir Nordine Rothschild Linda Preiss 《Journal of Geometric Analysis》2002,12(4):543-580
Results on finite determination and convergence of formal mappings between smooth generic submanifolds in ℂ
N
are established in this article. The finite determination result gibes sufficient conditions to guarantee that a formal map
is uniquely determined by its jet, of a preassigned order, at a point. Convergence of formal mappings for real-analytic generic
submanifolds under appropriate assumptions is proved, and natural geometric conditions are given to assure that if two germs
of such submanifolds are formally equivalent, then, they are necessarily biholomorphically equivalent. It is also shown that
if two real-algebraic hypersurfaces in ℂ
N
are biholomorphically equivalent, then, they are algebraically equivalent. All the results are first proved in the more general
context of “reflection ideals” associated to formal mappings between formal as well as real-analytic and real-algebraic manifolds. 相似文献
17.
Let V be a Euclidean Jordan algebra, Гthe associated symmetric cone and G be the identity component of the linear automorphism group of Г.In this paper we associate to a certain class of spherical representations (ρ, ɛ) of G certain ɛ-valued Riesz distributions
generalizing the classical scalar valued Riesz distributions on V. Our construction is motivated by the analytic theory of
unitary highest weight representations where it permits to study certain holomorphic families of operator valued Riesz distributions
whose positive definiteness corresponds to the unitarity of a representation of the automorphism group of the associated tube
domain Г +iV. 相似文献
18.
We consider the harmonic extension AN of an H-type group N with Lie algebra n = v + z, and [v, v] = z. We characterize the
positive definite spherical functions on AN. 相似文献
19.
We characterize the Besov-Lipschitz spaces with zero boundary conditions on bounded smooth domains. We prove that the appropriate
first and second difference norms are equivalent to the norm given in terms of the transition kernel of the Brownian motion
killed upon exit from the domain. 相似文献
20.
Halil Mete Soner 《Journal of Geometric Analysis》1997,7(3):477-491
In this paper, we study the short time behavior of the solutions of a sequence of Ginzburg-Landau equations indexed by ∈.
We prove that under appropriate assumptions on the initial data, solutions converge to ±1 in short time and behave like the
one-dimensional traveling wave across the interface. In particular, energy remains uniformly bounded in ∈.
Partially supported by the NSF Grant DMS-9200801 and by the Army Research Office through the Center for Nonlinear Analysis. 相似文献