共查询到20条相似文献,搜索用时 78 毫秒
1.
V. V. Makeev 《Journal of Mathematical Sciences》2003,113(6):812-815
A class of centrally-symmetric convex 12-topes (12-hedrons) in
is described such that for an arbitrary prescribed norm
on
each polyhedron in the class can be inscribed in (circumscribed about) the
-ball via an affine transformation, and this can be done with large degree of freedom. Bibliography: 5 titles. 相似文献
2.
Thomas Geisser 《K-Theory》1997,12(3):193-226
We prove that for W2
the Witt vectors of length two over the finite field
, we have
in characteristic at least 5 and
for (3,f) = 1. The result is proved by using the identity
and calculating the right term with a group homology spectral sequence. Some information on the spectral sequence is achieved by using the action of the outer automorphism of SL on the homology groups and recent results on K-groups of local rings and the ring of dual numbers over finite fields. 相似文献
3.
S. Ya. Novikov 《Journal of Mathematical Sciences》2004,120(5):1733-1751
We study operators
(not necessarily linear) defined on a quasi-Bahach space X and taking values in the space of real-valued Lebesgue-measurable functions. Factorization theorems for linear and superlinear operators with values in the space
are proved with the help of the Lorentz sequence spaces
. Sequences of functions belonging to fixed bounded sets in the spaces
are characterized for
and
. The possibility of distinguishing weak type operators (bounded in the space
) from operators factorizable through
is obtained in terms of sequences of independent random variables. A criterion under which an operator is symmetrically bounded in order in
, is established. Some refinements of the above-mentioned results are obtained for translation shift-invariant sets and operators. Bibliography: 30 titles. 相似文献
4.
E. G. Emelyanov 《Journal of Mathematical Sciences》2004,122(6):3648-3653
Let
be a finite Riemann surface. For a quadratic differential on
associated with a certain problem on extremal decomposition of
into n domains, a parametric family of quasiconformal mappings
, is defined. These mappings map the domains of the extremal decomposition of
onto the domains of the extremal decomposition of
.K This allows one to study the functional dependence of the problem on the parameters. Bibliography: 6 titles. 相似文献
5.
A. Yu. Makovetskii 《Journal of Mathematical Sciences》2003,113(6):818-821
Oriented special spines of 3-manifolds are studied. (Orientation is an additional structure on the spine, and each 3-manifold possesses a special spine with such a structure.) The transformations (moves)
and
of special spines, which do not change the manifold, are well known. It is proved that
and
preserve orientability of a spine, while
and
do not. For spines of homology balls, a class of moves is described allowing one to pass from a given orientation of a spine to any other orientation of the spine. Bibliography: 6 titles. 相似文献
6.
M. Bildhauer 《Journal of Mathematical Sciences》2003,115(6):2747-2752
Uniqueness is proved for solutions of the dual problem that is associated with the minimum problem
among the mappings
with prescribed Dirichlet boundary data and for smooth strictly convex integrands f of linear growth. No further assumptions on f or its conjugate function
are imposed, in particular,
is not assumed to be strictly convex. A special solution of the dual problem is seen to be a mapping into the image of
, which immediately implies uniqueness. Bibliography: 13 titles. 相似文献
7.
V.G. Osmolovskii 《Journal of Mathematical Sciences》2004,122(3):3278-3289
We consider the energy functional of a two-phase elastic medium
with quadratic energy densities
defined for
such that
,where
is a measurable characteristic function. Under some natural conditions on the data of the problem, we prove the existence of an interval (t
-,t
+) of the change of temperature
such that the energy functional has only a minimizer
such that
for
or
such that
t^ + $$
" align="middle" border="0">
. The energy functional has no minimizers
such that
or
if
. We derive two-sided estimates for the numbers
in terms of the characteristics of the two-phase elastic medium and the boundary condition. Bibliography: 3 titles. 相似文献
8.
S. S. Podkorytov 《Journal of Mathematical Sciences》2003,113(6):868-878
Let
. Assume that V is a manifold,
is the set of germs of n-dimensional oriented submanifolds of V, and
is the 2-module of all 2-valued functions on E
n
(V). If
is an oriented submanifold, let
be the indicator function of the set of germs of X. It is proved that there exists a quadratic map
such that for any compact oriented submanifold
one has the relation
, where
is the (rational) semicharacteristic of
, i.e., the residue class defined by the formula
Bibliography: 7 titles. 相似文献
9.
V. A. Zalgaller 《Journal of Mathematical Sciences》2001,104(4):1255-1258
Let
be nonempty convex bodies in
. Let
be vectors in
, let
, and let
. Then
is a convex set, and the family of sets
is concave. Let
. Then for the mean cross-sectional measures W_v (\Phi (\rho )),
, the functions
are concave on D. (Note that % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY-Hhbbf9v8qqaq% Fr0xc9pk0xbba9q8WqFfea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qq% Q8frFve9Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaaca% WGxbWaaSbaaSqaaiaaicdaaeqaaOGaaiikaiabfA6agjaacIcacqaH% bpGCcaGGPaGaaiykaiabg2da9iaabAfacaqGVbGaaeiBamaaBaaale% aatCvAUfKttLearyqr1ngBPrgaiuGacqWFRbWAaeqaaOGaeuOPdyKa% aiikaiabeg8aYjaacMcaaaa!4EE7!\[W_0 (\Phi (\rho )) = {\text{Vol}}_k\Phi (\rho )\] is the k-volume.) Bibliography: 2 titles. 相似文献
10.
D. E. Apushkinskaya H. Shahgholian N. N. Uraltseva 《Journal of Mathematical Sciences》2003,115(6):2720-2730
Let u and solve the problem
where is an open set in
0\} ,n \geqslant 2,H = \Delta - \partial _t \hfill \\ \hfill \\ \end{gathered} $$
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is the heat operator,
denotes the characteristic function of ,
is the unit cylinder in n+1,
, and the first equation is satisfied in the sense of distributions. We obtain the optimal regularity of the function u, i.e., we show that
. Bibliography: 6 titles. 相似文献
11.
An analog of the classical Fourier formula for the characteristic function of a convex compact set
is considered:
where W is a polyhedral in
. Bibliography: 6 titles. 相似文献
12.
Frédéric Paulin 《Geometriae Dedicata》2002,95(1):65-85
The aim of this paper is to give a geometric interpretation of the continued fraction expansion in the field
of formal Laurent series in X
–1 over
, in terms of the action of the modular group
on the Bruhat–Tits tree of
, and to deduce from it some corollaries for the diophantine approximation of formal Laurent series in X
–1 by rational fractions in X. 相似文献
13.
N. Guillotin-Plantard 《Journal of Theoretical Probability》2001,14(1):241-260
In this paper, we study a
d
-random walk
on nearest neighbours with transition probabilities generated by a dynamical system
. We prove, at first, that under some hypotheses,
verifies a local limit theorem. Then, we study these walks in a random scenery
, a sequence of independent, identically distributed and centred random variables and show that for certain dynamic random walks,
satisfies a strong law of large numbers. 相似文献
14.
A. N. Petrov 《Journal of Mathematical Sciences》2001,107(4):4067-4072
A new numerical inequality for average power means is presented. Let
and let
be a sequence of positive numbers. Consider the operator
. We denote by
the superposition of these operators. The following assertion is proved: if
. Bibliography: 2 titles. 相似文献
15.
O. L. Vinogradov 《Journal of Mathematical Sciences》2001,107(4):3987-4001
In what follows, C is the space of
-periodic continuous real-valued functions with uniform norm,
is the first continuity modulus of a function
with step h, H
n is the set of trigonometric polynomials of order at most n,
is the set of linear positive operators
(i.e., of operators such that
for every
),
is the space of square-integrable functions on
,
It is proved that
coincides with the smallest eigenvalue of some matrix of order n+1. The main result of the paper states that, for every
does not exceed and, for
, is equal to the minimum of the quadratic functional
over the unit sphere of
. Then it is calculated that
Bibliography: 19 titles. 相似文献
16.
G. V. Kuz'mina 《Journal of Mathematical Sciences》2003,118(1):4880-4894
We apply a variant of the method of the extremal metric to some problems concerning extremal decompositions and related problems. Let
be a system of distinct points on
and let
be the family of all systems
of nonoverlapping simply connected domains on
such that
. Let
where
is the reduced module of the domain
with respect to the point
. At present, the problem concerning the value
was solved completely for
. In this work, we continue the previous author's investigations and consider the case
. In addition, we consider the problem concerning the maximum of the sum
in the family
introduced above, where
, are arbitrary points of the circle
, and is a positive number. We prove that if
, then the maximum is attained only for systems of equidistant points of the circle
. For
, this result was obtained earlier by Dubinin who applied the method of symmetrization. It is shown that if
, where
is an even number, then equidistant points of the circle
do not realize the indicated maximum. Bibliography: 11 titles. 相似文献
17.
A. N. Frolov 《Journal of Mathematical Sciences》2002,109(6):2229-2240
Let
be a sequence of independent equidistributed random vectors with
. Let
, where
and
denotes the indicator function of the event in brackets. If, for example,
are the gains and
are the indicators of success in repetitions of a game of chance, then
is the maximal gain along head runs (sequences of successes without interruptions) of length j. We investigate the asymptotic behavior of the values
,
, where
is the length of the longest head run in
. We show that the asymptotics of the values
depend significantly on the growth rate of j and that these asymptotics vary from the strong noninvariance (as in the ErdsRéenyi law of large numbers) to the strong invariance (as in the CsöorgRévész strong approximation laws). We also consider the Shepp-type statistics. Bibliography: 17 titles. 相似文献
18.
The paper is devoted to the study of the similarity to self-adjoint operators of operators of the form
, in the space
with weight
. As is well known, the answer to this problem in the case
is positive; it was obtained by using delicate methods of the theory of Hilbert spaces with indefinite metric. The use of a general similarity criterion in combination with methods of perturbation theory for differential operators allows us to generalize this result to a much wider class of weight functions
. 相似文献
19.
Polynomial Approximations on a Family of Two Segments 总被引:1,自引:1,他引:0
Introduce the notation:
,is the union of two segments [- 1,1] and
is the Holder class with exponent on
is the Green function of the set
with a logarithmic pole at infinity,
0,\rho _h (z,\varepsilon ) = {\text{dist(}}z,L_h (\varepsilon ))$$
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. We prove the following result: There exist positive constants b()and a() depending only on such that if
then
.Bibliography: 3 titles. 相似文献
20.
A. A. Dosiev 《Functional Analysis and Its Applications》2003,37(1):61-64
This note deals with homological characteristics of algebras of holomorphic functions of noncommuting variables generated by a finite-dimensional nilpotent Lie algebra
. It is proved that the embedding
of the universal enveloping algebra
of
into its Arens–Michael hull
is an absolute localization in the sense of Taylor provided that
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