共查询到20条相似文献,搜索用时 62 毫秒
1.
Arthur Baragar 《Compositio Mathematica》2003,137(2):115-134
In this paper, we study the family of algebraic K3 surfaces generated by the smooth intersection of a (1, 1) form and a (2, 2) form in
defined over
and with Picard number 3. We describe the group of automorphisms
on V. For an ample divisor D and an arbitrary curve C
0 on V, we investigate the asymptotic behavior of the quantity
. We show that the limit
exists, does not depend on the choice of curve C or ample divisor D, and that .6515<<.6538. 相似文献
2.
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
3.
4.
5.
Let X be a complex analytic manifold,
a C
2 submanifold,
an openset with C
2 boundary
.Denote by
(resp.
) the microlocalization along M (resp.
) of the sheaf
of holomorphic functions.In the literature (cf. [A-G], [K-S 1,2])one encounters two classical results concerning the vanishing of the cohomology groups
.The most general gives the vanishing outside a range of indices j whose length is equal to
(with
being the number of respectively positive, negative and null eigenvalues for themicrolocal Levi form
).The sharpest result gives the concentration in a single degree, provided that the difference
is locally constant for
near p (with
for z the base point of p).The first result was restated for the complex
in [D'A-Z 2], in the case codim
We extend it here to any codimension and moreover we also restate for
the second vanishing theorem.We also point out that the principle of our proof, related to a criterion for constancy of sheaves due to [K-S 1], is a quite new one. 相似文献
6.
A. Cossidente J. W. P. Hirschfeld G. Korchmáros F. Torres 《Compositio Mathematica》2000,121(2):163-181
The number N of rational points on an algebraic curve of genus g over a finite field
satisfies the Hasse–Weil bound
. A curve that attains this bound is called maximal. With
and
, it is known that maximalcurves have
. Maximal curves with
have been characterized up to isomorphism. A natural genus to be studied is
and for this genus there are two non-isomorphic maximal curves known when
. Here, a maximal curve with genus g
2 and a non-singular plane model is characterized as a Fermat curve of degree
. 相似文献
7.
Yves Laurent 《Compositio Mathematica》1999,116(3):241-310
Considering a holonomic
-module and a hypersurface, we define a finite family of
-modules on the hypersurface which we call modules of vanishing cycles. The first one had been previously defined and corresponds to formal solutions. The last one corresponds, via Riemann-Hilbert, to the geometric vanishing cycles of Grothendieck-Deligne. For regular holonomic
-modules there is only one sheaf and for non regular modules the sheaves of vanishing cycles control the growth and the index of solutions. Our results extend to non holonomic modules under some hypothesis. 相似文献
8.
Bin Wang 《Compositio Mathematica》1999,115(3):303-327
Let X be an m dimensional smooth projective variety with a Kähler metric. We construct a metrized line bundle
with a rational section s over the product
of Chow varieties
such that
for disjoint A, B. That gives an answer to a part of Barry Mazur's proposal in a private communication to Bruno Horris about the Archimedean height pairing A, B on a smooth projective variety X. 相似文献
9.
Niels Jakob Laustsen 《K-Theory》2001,23(2):115-127
We prove that the K-groups of the Banach algebra
of bounded, linear operators on the pth James space
, where 1 < p < , are given by
and
. Moreover, for each Banach space
and each non-zero, closed ideal
contained in the ideal of inessential operators, we show that
and
. This enables us to calculate the K-groups of
for each Banach space
which is a direct sum of finitely many James spaces and
-spaces. 相似文献
10.
Let
be a hereditary torsion theory for the category
-mod of unital left
-modules over an associative ring
with an identity element. The purpose of this note is to prove that if the associated Gabriel filter
consists of finitely presented left ideals, then every module has a
-injective cover and if
contains a cofinal subset of finitely presented left ideals, then every module has a
-torsionfree
-injective cover. The methods used working with pure submodules contained in ``large" submodules also allow to unify the proofs of some previously known results. 相似文献
11.
Let
be a computable structure and let R be an additional relation on its domain. We establish a necessary and sufficient condition for the existence of an isomorphic copy
of
such that the image of R
is h-simple (h-immune) relative to
. 相似文献
12.
Let X be an open subset of
n and (f1, ...,fp): X
p be a holomorphic mapping. We prove that if (x0,0, 0) T* ×
p does not belong to the characteristic variety of the
X []-module
X[]f, then there exists a conic neighborhood V × of (x0, 0) such the function
is rapidely decreasing in | Im | for with Re bounded, for any (n,n)-form of class C with compact support in V. The following partial converse of this result is also established: if
for all (n,n)-forms of class C with compact support in X, then
. 相似文献
13.
Let be a finite-dimensional hereditary algebra over a finite field k,
() and
() be, respectively, the Hall algebra and the composition algebra of ,
be the isomorphism classes of finite dimensional -modules and I the isomorphism classes of simple -modules. We define and , in
, to be the right and left derivations of
() respectively. By using these derivations and the action of the braid group on the set of exceptional sequences of -mod, we provide an effective algorithm of calculating the root vectors of real Schur roots. This means that we get an inductive method to express u as the combinations of elements ui in the Hall algebra, where i I and in
is any exceptional -module. Because of the canonical isomorphism between the Drinfeld–Jimbo quantum group and the generic composition algebra, our algorithm is applicable directly to quantum groups. In particular, all the root vectors are obtained in this way in the finite type cases. 相似文献
14.
E. Getzler 《Compositio Mathematica》2002,132(2):121-135
We calculate the Euler characteristics of the local systems S
k
S
2
on the moduli space
2 of curves of genus 2, where
is the rank 4 local system R
1 *
. 相似文献
15.
Aderemi Kuku 《K-Theory》2001,22(4):367-392
Let
be a rational prime,
an exact category. In this article, we define and study for all
, the profinite higher K-theory of
, that is
as well as
, where
is the
-dimensional mod-
Moore space. We study connections between
and prove several
-completeness results involving these and associated groups including the cases where
is the category of finitely generated (resp. finitely generated projective) modules over orders in semi-simple algebras over number fields and p-adic fields. We also define and study continuous K-theory
of orders in p-adic semi-simple algebras and show some connection between the profinite and continuous K-theory of . 相似文献
16.
Stefano Cavallaro 《Algebras and Representation Theory》2000,3(2):175-186
Let
be an Abelian unital C
*-algebra and let
denote its Gelfand spectrum. We give some necessary and sufficient conditions for a nondegenerate representation of
to be unitarily equivalent to a representation in which the elements of
act multiplicatively, by their Gelfand transforms, on a space L
2(
,), where is a positive measure on the Baire sets of
. We also compare these conditions with the multiplicity-free property of a representation. 相似文献
17.
The 3-local geometry
of the sporadic simple group Co1 has been known to have a cover
with a flag-transitive automorphism group which is a nonsplit extension of an elementary Abelian 2-group of rank 24 (the Leech lattice modulo 2) by Co1. It was conjectured that
was simply connected. We disprove this conjecture by constructing a double cover
of
. The automorphism group of
is of the shape
. However, it is not isomorphic to the involution centralizer of the Monster sporadic simple group. 相似文献
18.
In this paper, we consider equations of the form
, where
is a function with values in the Hilbert space
, the operator B is symmetric, and the operator A is uniformly positive and self-adjoint in
. The linear operator
generating the C
0-semigroup in the energy space
is associated with this equation. We prove that this semigroup is exponentially stable if the operator B is uniformly positive and the operator A dominates B in the sense of quadratic forms. 相似文献
19.
20.
Let
be an
-filtered category in the sense of Karoubi. This is the categorical analogue of an ideal
in a ring
. Pedersen and Weibel constructed a fibration of K-theory spectra associated with the sequence
. We present a new easier proof based on Waldhausen' generic fibration. 相似文献