共查询到20条相似文献,搜索用时 46 毫秒
1.
Gabriela?Hinojosa Alberto?Verjovsky 《Bulletin of the Brazilian Mathematical Society》2008,39(2):157-171
In this paper, we first define discrete, smooth actions on
, whose limit sets are Cantor sets wildly embedded in
(Antoine's necklaces). Secondly, we define Schottky groups on real projective spaces of odd dimensions,
. We lift these actions to (locally) projective actions on the sphere
and consider the quotient space of the domain of discontinuity by the group to obtain new examples of manifolds with real
projective structures.
*This work was partially supported by PROMEP (SEP).
**This work was partially supported by CONACyT (México), grant U1 55084, PAPIIT (UNAM) grant IN102108. 相似文献
2.
In this paper self-adjoint realizations in Hilbert and Pontryagin spaces of the formal expression
are discussed and compared. Here L is a positive self-adjoint operator in a Hilbert space
with inner product 〈·,·〉, α is a real parameter, and φ in the rank one perturbation is a singular element belonging to
with n ≥ 3, where
is the scale of Hilbert spaces associated with L in
相似文献
3.
Mark Pankov 《Journal of Algebraic Combinatorics》2007,26(2):143-159
Let V and V′ be 2n-dimensional vector spaces over fields F and F′. Let also Ω: V× V→ F and Ω′: V′× V′→ F′ be non-degenerate symplectic forms. Denote by Π and Π′ the associated (2n−1)-dimensional projective spaces. The sets of k-dimensional totally isotropic subspaces of Π and Π′ will be denoted by and ${\mathcal G}'_{k}$, respectively. Apartments of the associated buildings intersect and by so-called base subsets. We show that every mapping of to sending base subsets to base subsets is induced by a symplectic embedding of Π to Π′. 相似文献
4.
Andreas Rosenschon 《K-Theory》2008,38(2):235-241
We give examples of smooth projective complex varieties of dimension d ≥ 4 and primes ℓ such that the morphic cohomology group is infinite, and is not finitely generated as a rational vector space. In particular, for these examples the semi-topological K-group has infinite dimension. 相似文献
5.
6.
The purpose of this paper is to give characterizations for uniform exponential dichotomy of evolution families on the real
line. We consider a general class of Banach function spaces denoted
and we prove that if
with
and the pair
is admissible for an evolution family
then
is uniformly exponentially dichotomic. By an example we show that the admissibility of the pair
for an evolution family is not a sufficient condition for uniform exponential dichotomy. As applications, we deduce necessary
and sufficient conditions for uniform exponential dichotomy of evolution families in terms of the admissibility of the pairs
and
with
相似文献
7.
Hans Werner Schuster 《manuscripta mathematica》1969,1(2):125-137
This article deals with deformations of compact complex spaces, the parameter-space being a general complex space. A compact space X0 is called absolutely rigid, if every deformation of X0 is trivial. Ex(X0,
) is defined as the group of the extensions of
by
and it is shown that X0 is absolutely rigid if and only if Ex(X0,
)=0.If X0 is reduced, there is Ex(X0,
). The proof makes use of the results of M.A{uprtin} [1] and D{upouady} [2]. 相似文献
8.
A contact-stationary Legendrian submanifold of is a Legendrian submanifold whose volume is stationary under contact deformations. The simplest contact-stationary Legendrian
submanifold (actually minimal Legendrian) is the real, equatorial n-sphere S
0. This paper develops a method for constructing contact-stationary (but not minimal) Legendrian submanifolds of by gluing together configurations of sufficiently many many U(n + 1)-rotated copies of S
0. Two examples of the construction, corresponding to finite cyclic subgroups of U(n + 1) are given. The resulting submanifolds
are very symmetric; are geometrically akin to a ‘necklace’ of copies of S
0 attached to each other by narrow necks and winding a large number of times around before closing up on themselves; and are topologically equivalent to . 相似文献
9.
Yi Hu 《Compositio Mathematica》1999,118(2):159-187
In this paper, certain natural and elementary polygonal objects in Euclidean space, the stable polygons, are introduced, and the novel moduli spaces
of stable polygons are constructed as complex analytic spaces. Quite unexpectedly, these new moduli spaces are shown to be projective and isomorphic to the moduli space
of the Deligne–Mumford stable curves of genus 0. Further, built into the structures of stable polygons are some natural data giving rise to a family of (classes of) symplectic (Kähler) forms. This, via the link to
, brings up a new tool to study the Kähler topology of
. A wild but precise conjecture on the shape of the Kähler cone of
is given in the end. 相似文献
10.
Euisung Park 《Mathematische Zeitschrift》2007,256(3):685-697
In this article we study nondegenerate projective curves of degree d which are not arithmetically Cohen-Macaulay. Note that for a rational normal curve and a point . Our main result is about the relation between the geometric properties of X and the position of P with respect to . We show that the graded Betti numbers of X are uniquely determined by the rank of P with respect to . In particular, X satisfies property N
2,p
if and only if . Therefore property N
2,p
of X is controlled by and conversely can be read off from the minimal free resolution of X. This result provides a non-linearly normal example for which the converse to Theorem 1.1 in (Eisenbud et al., Compositio
Math 141:1460–1478, 2005) holds. Also our result implies that for nondegenerate projective curves of degree d which are not arithmetically Cohen–Macaulay, there are exactly distinct Betti tables. 相似文献
11.
Rachelle C. DeCoste 《manuscripta mathematica》2008,127(3):309-343
We study the distribution of closed geodesics on nilmanifolds Γ \ N arising from a 2-step nilpotent Lie algebra constructed from an irreducible representation of a compact semisimple Lie algebra on a real finite dimensional vector space U. We determine sufficient conditions on the semisimple Lie algebra for Γ \ N to have the density of closed geodesics property where Γ is a lattice arising from a Chevalley rational structure on . 相似文献
12.
13.
This paper using a geometric approach produces vanishing and nonvanishing results concerning the spaces of twisted symmetric
differentials on subvarieties , with k ≤ m. Emphasis is given to the case of k = m which is special and whose nonvanishing results on the dimensional range dim X > 2/3(N − 1) are related to the space of quadrics containing X and the variety of all tangent trisecant lines of X. The paper ends with an application showing that the twisted symmetric plurigenera, along smooth families of projective varieties Xt are not invariant even for α arbitrarily large.
Received: September 2006, Revision: May 2007, Accepted: June 2007 相似文献
14.
We study several deformation functors associated to the normalization of a reduced curve singularity . The main new results are explicit formulas, in terms of classical invariants of (X, 0), for the cotangent cohomology groups T
i
, i = 0,1,2, of these functors. Thus we obtain precise statements about smoothness and dimension of the corresponding local
moduli spaces. We apply the results to obtain explicit formulas, respectively, estimates for the -codimension of a parametrized curve singularity, where denotes the Mather–Wall group of left-right equivalence. 相似文献
15.
We show that Fourier transforms on the Weyl algebras have a geometric counterpart in the framework of toric varieties, namely
they induce isomorphisms between twisted rings of differential operators on regular toric varieties, whose fans are related
to each other by reflections of one-dimensional cones. The simplest class of examples is provided by the toric varieties related
by such reflections to projective spaces. It includes the blow-up at a point of the affine space and resolution of singularities
of varieties appearing in the study of the minimal orbit of
. 相似文献
16.
In this paper we construct certain moduli spaces, which we call
moduli spaces of (principal) F-bundles,
and study their basic properties. These spaces are
associated to triples consisting of a smooth projective geometrically
connected curve over a finite field, a split
reductive group G, and an irreducible
algebraic representation
.of
of
Our spaces generalize moduli
spaces of F-sheaves, studied
by Drinfeld and Lafforgue, which correspond to the case G
= GLr
and
is the tensor product of the standard
representation and its dual. The importance of the moduli spaces
of F-bundles is due to the
belief that Langlands correspondence is realized in their cohomology. 相似文献
17.
In this paper we classify point sets of minimum size of two types (1) point sets meeting all secants to an irreducible conic
of the desarguesian projective plane PG(2,q), q odd; (2) point sets meeting all external lines and tangents to a given irreducible conic
of the desarguesian projective plane PG(2,q), q even. 相似文献
18.
19.
J. S. Manhas 《Integral Equations and Operator Theory》2008,62(3):419-428
Let be the weighted Banach space of analytic functions with a topology generated by weighted sup-norm. In the present article,
we investigate the analytic mappings and which characterize the compactness of differences of two weighted composition operators on the space . As a consequence we characterize the compactness of differences of composition operators on weighted Bloch spaces.
相似文献
20.
Shan Zhen LU Li Fang XU 《数学学报(英文版)》2006,22(1):105-114
In this paper, the authors study the boundedness properties of μΩ↑m,b generated by the function b ∈Lipβ(R^n)(0 〈β≤ 1/m) and the Marcinkiewicz integrals operator μΩ. The boundednesses are established on the Hardy type spaces Hb^m^p,n(R^n) and the Herz Hardy type spaces Hbm Kq^α,p(R^b). 相似文献