共查询到20条相似文献,搜索用时 616 毫秒
1.
Frank Müller 《Calculus of Variations and Partial Differential Equations》2005,24(3):283-288
Let $P={\rm \Gamma}\cap{\cal S}Let
be the point of non-tangential intersection of a closed Jordan arc
and an embedded, regular support surface
. Let
be a conformally parametrized solution of
with partially free boundaries
. It is proved, that
is H?lder continuous up to
with
, whenever
meets
orthogonally along its free trace. This provides a regularity result for stationary minimal surfaces and is applicable also
to surfaces of prescribed bounded mean curvature.
Mathematics Subject Classification (2000) 53 A 10, 35 J 65, 35 R 35, 49 Q 05 相似文献
2.
Christoph Scheven 《Calculus of Variations and Partial Differential Equations》2006,25(4):409-429
Let
and
be Riemannian manifolds,
compact without boundary. We develop a definition of a variationally harmonic map
with respect to a general boundary condition of the kind u(x)∊Γ(x) for a.e.
, where
are given submanifolds depending smoothly on x. The given definition of variationally harmonic maps is slightly more restrictive, but also more natural than the usual definition
of stationary harmonic maps. After deducing an energy monotonicity formula, it is possible to derive a regularity theory for
variationally harmonic maps with general boundary data. The results include full boundary regularity in the Dirichlet boundary
case Γ(x) = {g(x)} for
if
does not carry a nonconstant harmonic 2-sphere. 相似文献
3.
Antonio G. García Miguel A. Hernández-Medina 《Mediterranean Journal of Mathematics》2005,2(3):345-356
Let
be a symmetric operator with compact resolvent defined in a Hilbert space
For any fixed
we consider an entire
function Ka which involves the resolvent of
Associated with Ka we obtain, by duality in
a Hilbert space
of entire functions which becomes a De Branges space of entire functions. This property provides a characterization of
regardless of the anti-linear mapping which has
as its range space. There exists also a sampling formula allowing to recover any function in
from its samples at the sequence of eigenvalues of
This work has been supported by the grant BFM2003–01034 from the D.G.I. of the Spanish Ministerio de Ciencia y Tecnología. 相似文献
4.
Jaeyoung Byeon Junsang Park 《Calculus of Variations and Partial Differential Equations》2005,24(4):459-477
Let
be a connected compact smooth Riemannian manifold of dimension
with or without smooth boundary
We consider the following singularly perturbed nonlinear elliptic problem on
where
is the Laplace-Beltrami operator on
,
is an exterior normal to
and a nonlinearity
of subcritical growth. For certain
there exists a mountain pass solution
of above problem which exhibits a spike layer. We are interested in the asymptotic behaviour of the spike layer.
Without any non-degeneracy condition and monotonicity of
we show that if
the peak point
of the solution
converges to a maximum point of the scalar curvature
on
(the mean curvature
on
as
respectively.
The research of the first author was supported in part by KRF-2002-070-C000005 of Korea Research Foundation. 相似文献
5.
Hans-Peter Schröcker 《Journal of Geometry》2005,82(1-2):172-187
We study the projective space
of univariate rational parameterized equations of degree d or less in real projective space
The parameterized equations of degree less than d form a special algebraic variety
We investigate the subspaces on
and their relation to rational curves in
give a geometric characterization of the automorphism group of
and outline applications of the theory to projective kinematics. 相似文献
6.
D. Jakubíková-Studenovská 《Algebra Universalis》2009,60(2):125-143
In the present paper we prove that the collection of all convexities of partial monounary algebras is finite; namely, it has exactly 23 elements. Further, we show that for
each element there exists a subset of such that is generated by and card .
This work was supported by the Science and Technology Assistance Agency under the contract No. APVT-20-004104. Supported by
Grant VEGA 1/3003/06. 相似文献
7.
Lutz Strüngmann 《Archiv der Mathematik》2006,86(3):193-204
Let R be a unital associative ring and
two classes of left R-modules. In this paper we introduce the notion of a
In analogy to classical cotorsion pairs as defined by Salce [10], a pair
of subclasses
and
is called a
if it is maximal with respect to the classes
and the condition
for all
and
Basic properties of
are stated and several examples in the category of abelian groups are studied.
Received: 17 March 2005 相似文献
8.
Gregory D. Landweber 《K-Theory》2005,36(1-2):115-168
Given a Lie superalgebra
, we introduce several variants of the representation ring, built as subrings and quotients of the ring
of virtual
-supermodules, up to (even) isomorphisms. In particular, we consider the ideal
of virtual
-supermodules isomorphic to their own parity reversals, as well as an equivariant K-theoretic super representation ring
on which the parity reversal operator takes the class of a virtual
-supermodule to its negative. We also construct representation groups built from ungraded
-modules, as well as degree-shifted representation groups using Clifford modules. The full super representation ring
, including all degree shifts, is then a
-graded ring in the complex case and a
-graded ring in the real case. Our primary result is a six-term periodic exact sequence relating the rings
, and
. We first establish a version of it working over an arbitrary (not necessarily algebraically closed) field of characteristic
0. In the complex case, this six-term periodic long exact sequence splits into two three-term sequences, which gives us additional
insight into the structure of the complex super representation ring
. In the real case, we obtain the expected 24-term version, as well as a surprising six-term version, of this periodic exact
sequence.
(Received: October 2004) 相似文献
9.
Let
be a family of unit balls in
with the property that the mutual distances of the centers are at least
. If any n2 members of
have a common line transversal, then
has a line transversal too.
Received: 27 January 2005; revised: 17 October 2005 相似文献
10.
Yury M. Arlinskiĭ Seppo Hassi Henk S. V. de Snoo 《Complex Analysis and Operator Theory》2009,3(1):19-56
Passive systems with and as an input and output space and as a state space are considered in the case that the main operator on the state space is normal. Basic properties are given
and a general unitary similarity result involving some spectral theoretic conditions on the main operator is established.
A passive system with is said to be quasi-selfadjoint if ran . The subclass of the Schur class is the class formed by all transfer functions of quasi-selfadjoint passive systems. The subclass is characterized and minimal passive quasi-selfadjoint realizations are studied. The connection between the transfer function
belonging to the subclass and the Q-function of T is given.
Received: December 16, 2007., Accepted: March 4, 2008. 相似文献
11.
Let M be a right R-module,
the class of all M-small modules, and P a projective cover of M in
[M]. We consider the torsion theories
= (
),
= (
), and
= (
) in
[M], where
is the torsion theory generated by
is the torsion theory cogenerated by
, and
is the dual Lambek torsion theory. We study some conditions for
to be cohereditary, stable, or split, and prove that Rej(M,
) = M
=
(=
=
)
=
GenM(P)
.2000 Mathematics Subject Classification: 16S90 相似文献
12.
Let
be a compact Riemannian manifold without boundary. In this paper, we consider the first nonzero eigenvalue of the p-Laplacian
and we prove that the limit of
when
is 2/d(M), where d(M) is the diameter of M. Moreover, if
is an oriented compact hypersurface of the Euclidean space
or
, we prove an upper bound of
in terms of the largest principal curvature κ over M. As applications of these results, we obtain optimal lower bounds of d(M) in terms of the curvature. In particular, we prove that if M is a hypersurface of
then:
.
Mathematics Subject Classifications (2000): 53A07, 53C21. 相似文献
13.
Christian Richter 《Journal of Geometry》2006,84(1-2):117-132
Let
be a group of affine transformations of the Euclidean plane
. Two topological discs D,
are called congruent by dissection with respect to
if D can be dissected into a finite number of subdiscs that can be rearranged by maps from
to a dissection of E.
Our main result says in particular that
admits congruence by dissection of any circular disc C with any square S if and only if
contains a contractive map and all orbits
,
, are dense in
. In this case any two discs D and E are congruent by dissection with respect to
and every disc D is congruent by dissection with n copies of D for every n ≥ 2.
Moreover, we give estimates on minimal numbers of pieces that are needed to realize congruences by dissection.
Dedicated to Irmtraud Stephani on the occasion of her 70th birthday 相似文献
14.
The optimal value function
of the quadratic program
, where
is a given symmetric matrix,
a given matrix,
and
are the linear perturbations, is considered. It is proved that
is directionally differentiable at any point
in its effective domain
. Formulae for computing the directional derivative
of
at
in a direction
are obtained. We also present an example showing that, in general,
is not piecewise linear-quadratic on W. The preceding (unpublished) example of Klatte is also discussed. 相似文献
15.
Chong LI Genaro LOPEZ 《数学学报(英文版)》2006,22(3):741-750
Let B (resp. K, BC,KC) denote the set of all nonempty bounded (resp. compact, bounded convex, compact convex) closed subsets of the Banach space X, endowed with the Hausdorff metric, and let G be a nonempty relatively weakly compact closed subset of X. Let B° stand for the set of all F ∈B such that the problem (F, G) is well-posed. We proved that, if X is strictly convex and Kadec, the set KC ∩ B° is a dense Gδ-subset of KC / G. Furthermore, if X is a uniformly convex Banach space, we will prove more, namely that the set B /B° (resp. K / B°, BC /B°, KC / B°) is a-porous in B (resp. K,BC, KC). Moreover, we prove that for most (in the sense of the Baire category) closed bounded subsets G of X, the set K / B° is dense and uncountable in K. 相似文献
16.
The main result in Cossidente and Siciliano (J. Number Theory, Vol. 99 (2003) pp. 373–382) states that if a Singer subgroup of PGL(3,q) is an automorphism group of a projective, geometric
irreducible, non-singular plane algebraic curve
then either
or
. In the former case
is projectively equivalent to the curve
with equation Xq+1Y+Yq+1+X=0 studied by Pellikaan. Furthermore, the curve
has a very nice property from Finite Geometry point of view: apart from the three distinguished points fixed by the Singer
subgroup, the set of its
-rational points can be partitioned into finite projective planes
. In this paper, the full automorphism group of such curves is determined. It turns out that
is the normalizer of a Singer group in
. 相似文献
17.
Oscar Perdomo 《Journal of Geometry》2006,84(1-2):100-105
In this paper we prove that if
is a closed minimal surface, then,
, for any homogeneous polynomial f of degree 3 with 0 a regular value of the function
. 相似文献
18.
In the present paper we suggest an explicit construction of a Cartan connection for an elliptic or hyperbolic CR manifold
M of dimension six and codimension two, i.e. a pair
, consisting of a principal bundle
over M and of a Cartan connection form
over P, satisfying the following property: the (local) CR transformations
are in one to one correspondence with the (local) automorphisms
for which
. For any
, this construction determines an explicit monomorphism of the stability subalgebra Lie (Aut(M)x) into the Lie algebra
of the structure group H of P.
Mathematics Subject Classification (2000) Primary 32V05, Secondary 53C15, 53A55 相似文献
19.
We show that for a variety
of Heyting algebras the following conditions are equivalent: (1)
is locally finite; (2) the
-coproduct of any two finite
-algebras is finite; (3) either
coincides with the variety of Boolean algebras or finite
-copowers of the three element chain
are finite. We also show that a variety
of Heyting algebras is generated by its finite members if, and only if,
is generated by a locally finite
-algebra. Finally, to the two existing criteria for varieties of Heyting algebras to be finitely generated we add the following
one:
is finitely generated if, and only if,
is residually finite.
Received November 11, 2001; accepted in final form July 25, 2005. 相似文献
20.
Let
be the Poisson point process with intensity 1 in Rd and let
be
. We obtain a strong invariance principle for the total length of the nearest-neighbor graph on
. 相似文献