共查询到20条相似文献,搜索用时 734 毫秒
1.
Yasunori Fujikoshi Yoshimichi Ochi 《Annals of the Institute of Statistical Mathematics》1984,36(1):119-128
Summary In this paper we obtain an asymptotic expansion of the distribution of the maximum likelihood estimate (MLE)
based onT observations from the first order Gaussian process up to the term of orderT
−1. The expansion is used to compare
with a generalized estimate
including the least square estimate (LSE)
, based on the asymptotic probabilities around the true value of the estimates up to the terms of orderT
−1. It is shown that
(or the modified MLE
) is better than
(or the modified estimate
). Further, we note that
does not attain the bound for third order asymptotic median unbiased estimates. 相似文献
2.
XuSenlin DengQintao ChenDongmei 《分析论及其应用》2004,20(3):288-293
Let M be a compact minimal hypersurface of sphere Sn 1(1). Let (M) be H (r)-torus of sphere Sn 1 (1).Assume they have the same constant mean curvature H, the result in [1] is that ifSpec0(M, g) =Spec0((M), g),then for 3≤ n ≤ 6, r2≤n-1/n or n ≥ 6, r2 ≥ n-1, then M is isometric to (M). We improved the result and prove that: if Spec0(M,g) =Spec0((M),g), then M is isometric to (M). Generally, if Specp(M,g) =Specp((M),g), here p is fixed and satisfies that n(n - 1) ≠ 6p(n - p), then M is isometric to (M). 相似文献
3.
Gerhard Edelmann 《manuscripta mathematica》1994,82(1):393-406
Let
be a 3-dimensional submanifold of ℙ5 of degree 12. This article gives, up to one case, a complete classification of the deformation classes of those 3-folds.
The main tools used are methods already applied in the classification of degrees 9 to 11 and adjunction theoretic results.
We show here how the 2nd reduction of
can be applied to analyse the birational structure of
or even exclude the existence of
. 相似文献
4.
We obtain a set of necessary and sufficient conditions for
to imply
for 1 <k ≤ s < ∞. Using this result we establish several inclusion theorems as well as conditions for the equivalence of
and
. 相似文献
5.
Jong Taek Cho 《Israel Journal of Mathematics》1999,109(1):299-318
N. Tanaka ([10]) defined the canonical affine connection on a nondegenerate integrable CR manifold. In the present paper,
we introduce a new class of contact Riemannian manifolds satisfying (C) (
for any unit
-geodesic (
, where
is the generalized Tanaka connection. In particular, when the associated CR structure of a given contact Riemannian manifold
is integrable we have a structure theorem and find examples which are neither Sasakian nor locally symmetric but satisfy the
condition (C).
This work was supported in part by BSRI 98-1425. 相似文献
6.
Tamara R. Lefcourt 《Israel Journal of Mathematics》1999,114(1):323-346
Consider a domain
that is complete with respect to a non-zero prime ideal. This paper proves two Galois-theoretic results about such rings.
Using Grothendieck’s Existence Theorem we prove that every finite group occurs as the Galois group of a Galois extension of
. This generalizes results of David Harbater who proved the result in the case where the ideal is maximal and the domain is
normal. As a consequence, we deduce that if
is a Noetherian domain that is complete with respect to a non-zero prime ideal, then every finite group occurs as a Galois
group over
. This proves the Noetherian case of a conjecture posed by Moshe Jarden. 相似文献
7.
Let
and
be a perturbed eigenpair of a diagonalisable matrixA. The problem is to bound the error in
and
. We present one absolute perturbation bound and two relative perturbation bounds.
The absolute perturbation bound is an extension of Davis and Kahan's sin θ Theorem from Hermitian to diagonalisable matrices.
The two relative perturbation bounds assume that
and
are an exact eigenpair of a perturbed matrixD
1
AD
2
, whereD
1 andD
2 are non-singular, butD
1
AD
2 is not necessarily diagonalisable. We derive a bound on the relative error in
and a sin θ theorem based on a relative eigenvalue separation. The perturbation bounds contain both the deviation ofD
1 andD
2 from similarity and the deviation ofD
2 from identity.
This work was partially supported by NSF grant CCR-9400921. 相似文献
8.
Let
and
be adjoint nilpotent orbits in a real semisimple Lie algebra. Write
≥
if
is contained in the closure of
. This defines a partial order on the set of such orbits, known as the closure ordering. We determine this order for the split
real form of the simple complex Lie algebra, E
8. The proof is based on the fact that the Kostant-Sekiguchi correspondence preserves the closure ordering. We also present
a comprehensive list of simple representatives of these orbits, and list the irreeducible components of the boundaries
and of the intersections
. 相似文献
9.
B. Yousefi 《Rendiconti del Circolo Matematico di Palermo》2000,49(1):115-120
Let
be a sequence of positive numbers and 1 ≤p < ∞. We consider the spacel
P(β) of all power series
such that
. We give a necessary and sufficient condition for a polynomial to be cyclic inl
P(β) and a point to be bounded point evaluation onl
P(β). 相似文献
10.
Summary LetG be the coadjoint group of a finite-dimensional complex Lie algebrag. Forg solvable, the Dixmier-map is known to be a homeomorphism
of the orbit space
/G onto the space χ of primitive ideals in the enveloping algebra U(G) [6,15]. For
, the Dixmier-map is known to be a bijection (and in general not a homeomorphism)
with the space χl of all completely prime primitive ideals [7, 16]. Here we derive from a result ofW. SOERGEL [18], that this map issheet- wise a homeomorphism onto the image. Here a sheet is a maximal irreducible subset consisting of orbits of a fixed dimension; obviouslyg decomposes into finitely many sheets [3]. The results of this paper hold more generally forg semisimple, if one restricts to a sheet of polarizable orbits, where a Dixmier-map can be defined.
Relative to a fixed polarization (a parabolic subalgebra)p ⊂g let I be the annihilator of the generic module induced from p. The „relative enveloping algebra“
) has been studied e.g. bySOERGEL [19, 18]. Its center Z is described here by a relative Harish-Chandra isomorphism of the normalization
with a suitable ring of group invariants (3.2). We study here the extension
ofU by
. We suggest that this very mild central extension ofU generates good properties and is very suitable for the study of the Dixmier-map (cf.4.3,5.6).
In particular, we conjecture in case
: Every minimal primitive ideal of
is generated by a maximal ideal of the center. This would generalize for
a well known theorem ofM. Duflo (casep Borel, where
).
AsJ. Dixmier communicated in a letter, the main result here is exactly what he had hoped for when he first introduced a notion of sheets
many years ago.
Added in proof: This conjecture will be proved in a subsequent paper. 相似文献
Added in proof: This conjecture will be proved in a subsequent paper. 相似文献
11.
Arthur Moór 《Annali di Matematica Pura ed Applicata》1961,54(1):255-273
Zusammenfassung Das invariante Differential eines Vektors
ist selbst ein Vektor, der vom Orte xi, von dxi,
und von
selbst abh?ngig ist. Es wird nun infolge dieser Definition in einigen F?llen die m?gliche Form des invarianten Differentials
bestimmt.
Enrico Bompiani zu seinem wissenschaftlichen Jubil?um. 相似文献
12.
Let
be aC-lattice which is strong join principally generated. In this paper, we consider prime elements of
for which every semiprimary element is primary. We show, for example, that a compact nonmaximal primep with this property is principal. We also show that if every primepm has this property, then
is either a one dimensional domain or a primary lattice. It follows that if every primep satisfies the property, and if there are only a finite number of minimal primes in
, then
is the finite direct product of one-dimensional domains and primary lattices. 相似文献
13.
D. N. Dudin 《Mathematical Notes》1968,3(1):42-44
For an algebra
of subsets of a set X there is constructed a set
and an algebra of its subsets so that the mapping
is a one-to-one correspondence between
and
and for each additive measure on
the measure
on
defined by the equation
is countably additive.Translated from Matematicheskie Zametki, Vol. 3, No. 1, pp. 71–76, January, 1968.The author wishes to express his deep appreciation to S. V. Fomin, under whose guidance this paper was written. 相似文献
14.
Ivan Č. Jovanović Eberhard Malkowsky Vladimir Rakočević 《Rendiconti del Circolo Matematico di Palermo》2003,52(2):308-314
LetF be aBK space withAK and
denote the set of all formal power series
with
such that
ε F for the sequence of coefficients of
. We give a necessary and sufficient condition for a point to be a bounded point evaluation on
, and for a polynomial to be cyclic in
. As special cases, we obtain the results for the space ℓ
p
(β) in [7].
Research of the authors supported under the research project #1232 of the Serbian Ministry of Sciences and Tecnology and,
in the case of the second author, also by the DAAD foundation (German Academic Exchange Service), grant 911 103 102 8. 相似文献
15.
Götz Brunner 《Israel Journal of Mathematics》1972,12(3):306-313
In the definition ofCW-complexes, the one-point spaceP, respectively the spaceP∪* with basepoint *, play the roll of the only “building-stone”. Let
be a family of compact spaces. Then the definition of a generalizedCW-complex over
is obtained from the definition of aCW-complex by replacingP by the spaces of
and formation of the mapping cone by a slightly modified construction. LetCW
* denote the category of all pointed spaces which have the homotopy type of a generalizedCW-complex over
. If
, thenCW
* is the category of all pointedCW-spaces.CW
* is closed under the formation of direct sums and of mapping cones, cylinders and tori, and is formally characterized as
the smallest such subcategory of Top * containing the spaces W∪*,
. Following the methods of E. H. Brown, it is proved, that any half exact homotopy functor onCW
* is representable, and any cohomology theory onCW
is naturally equivalent to the cohomology theory of an Ω-spectrum; for example, the singular cohomo logy is representable
onCW
for any family
of compact spaces.
相似文献
16.
Graeme West 《Integral Equations and Operator Theory》1995,22(3):352-359
Suppose
is a von Neumann algebra on a Hilbert space
and
is any ideal in
. We determine a topology
on
, for which the members of
that are
to norm continuous are exactly those in
; and a bornology
on
such that the elements of
which map the unit ball to an element of
, equivalently those members of
that are norm to
bounded, are exactly those in
. This is achieved via analogues of the notions of injectivity and surjectivity in the theory of operator ideals on Banach spaces. 相似文献
17.
Ferenc Weisz 《Acta Mathematica Hungarica》2002,96(1-2):149-160
A general summability method of two-dimensional Fourier transforms is given with the help of an integrable function
. Under some conditions on
we show that the maximal operator of the Marcinkiewicz-
-means of a tempered distribution is bounded from
to
for all
and, consequently, is of weak type
, where
depends only on
. As a consequence we obtain a generalization for Fourier transforms of a summability result due to Marcinkievicz and Zhizhiashvili,
more exactly, the Marcinkiewicz-
-means of a function
converge a.e. to the function in question. Moreover, we prove that the Marcinkiewicz-
-means are uniformly bounded on the spaces
and so they converge in norm
. Some special cases of the Marcinkievicz-
-summation are considered, such as the Weierstrass, Picar, Bessel, Fejér, de la Vallée-Poussin, Rogosinski and Riesz summations.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
18.
T. Levasseur 《Transformation Groups》1998,3(4):337-353
Let
u
be a compact Lie algebra and let
u
be its complexification. Let ζ−1/2 be the inverse on the set of regular elements of
u
of a square root of the discriminant of
. Generalizing a result of W. Lichtenstein in the case
u
=
(n, ℂ) or
(nℝ), we prove that ∂(q).ζ1/2 is non zero for all harmonic polynomialsq ∈S(
) \ {0}. This fact is deduced from results about equivariantD-modules supported on the nilpotent cone of
. 相似文献
19.
LetW be an open Riemann surface and
ap-sheeted (1<p<∞) unlimited covering surface ofW. Denote by Δ1 (resp.,
) the minimal Martin boundary ofW (resp.,
). For ζ ∈ Δ, let
ζ be the (cardinal) number of the set of pionts
which lie over ζ and
the class of open connected subsetsM ofW such thatM∪{ζ} is a minimal fine neighborhood of ζ. Our main result is the following:
, where
is the number of components of π-1
M and π is the projection of
ontoW. Moreover, some applications of the above results are discussed whenW is the unit disc. 相似文献
20.
Tiow-Seng Tan 《Discrete and Computational Geometry》1996,15(2):169-193
This paper shows that, for any plane geometric graph
withn vertices, there is a triangulation
that conforms to
, i.e., each edge of
is the union of some edges of
, where
hasO(n2) vertices with each angle of its triangles measuring no more than 11/15π. Additionally,
can be computed inO(n
2 logn) time.
This research was partially supported by the National University of Singapore under Grant RP940641. 相似文献