共查询到20条相似文献,搜索用时 31 毫秒
1.
Michael Koren 《Israel Journal of Mathematics》1973,15(4):396-403
It is shown that the realizability of the sequences ϕ=(a
1,…,
a
), ψ=(b
1,…,b
n
) and ϕ+ψ is a sufficient condition for the realizability of ϕ+ψ by a graph with a ϕ-factor ifb
i
≦1 fori=1,…,n. The condition is not sufficient in general. A necessary and sufficient condition for the realizability of ϕ+ψ by a graph
with a ϕ-factor is given for the case that ϕ is realizable by a star and isolated vertices. 相似文献
2.
Shun Shimomura 《Journal d'Analyse Mathématique》2000,82(1):333-346
We examine value distribution properties of the first and the second Painlevé transcendents. For every transcendental meromorphic
solution ϕ(z) (resp. ψ(z)) of the first (resp. second) Painlevé equation, the deficiency δ(g,ϕ) (resp. δ(g, ψ)) of a small functiong(z) does not exceed 1/2. Furthermore, for ϕ(z), the ramification index satisfies ϑ(gφ)≤5/12. 相似文献
3.
Yoshinori Hamahata 《manuscripta mathematica》1993,79(1):307-327
We define the tensor product ϕ ⊗ ψ and relatedt-modules Sym2(ϕ), and ∧2(ϕ) for Drinfeld modules ϕ, ψ defined over the rational function fieldK=F
q
(T), and describe thev-adic Tate modules of theset-modules by using those of ϕ, ψ. 相似文献
4.
M. F. Gamal’ 《Journal of Mathematical Sciences》2008,148(6):830-840
Let T be a Toeplitz operator on the Hardy space H2 on the unit circle, and let the symbol of T be of the form ϕ/ψ, where ϕ is an inner function, ψ is a finite Blaschke product,
and deg ψ ≤ deg ϕ. D. N. Clark proved that such an operator T is similar to an isometry. In this paper, we find necessary
and sufficient conditions under which such an operator T is similar to a unilateral shift. Bibliography: 20 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 345, 2007, pp. 85–104. 相似文献
5.
B. I. Peleshenko 《Ukrainian Mathematical Journal》2005,57(11):1741-1762
We prove theorems on interpolation of quasilinear operators of weak type (ϕ0, ψ0, ϕ0, ψ1) in Lorentz spaces. The operators under study are analogs of the Calderón operator and the Benett operator for concave and
convex functions ϕ0(t), ψ0(t), ϕ1(t), and ψ1(t).
__________
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 57, No. 11, pp. 1490–1507, November, 2005. 相似文献
6.
We investigate the mixing coefficients of interval maps satisfying Rychlik's conditions. A mixing Lasota-Yorke map is reverse
ϕ-mixing. If its invariant density is uniformly bounded away from 0, it is ϕ-mixing iff all images of all orders are big,
in which case it is ψ-mixing. Among β-transformations, non-ϕ-mixing is generic. In this sense, the asymmetry of ϕ-mixing is
natural. 相似文献
7.
Let ϕ and ψ be holomorphic self-maps of the unit disk, and denote by C
ϕ
, C
ψ
the induced composition operators. This paper gives some simple estimates of the essential norm for the difference of composition
operators C
ϕ
−C
ψ
from Bloch spaces to Bloch spaces in the unit disk. Compactness of the difference is also characterized. 相似文献
8.
We characterize hyponormal “rational” Toeplitz pairs which are pairs of Toeplitz operators whose symbols are rational functions
in L∞. The main result of this article is as follows. If T = (Tϕ, Tψ) is a hyponormal rational Toeplitz pair then ϕ − βψ ∈H2 for some constant β; in other words, their co-analytic parts necessarily coincide up to a constant multiple. As a corollary we get a complete
characterization of hyponormal rational Toeplitz pairs. 相似文献
9.
M. Malejki 《Semigroup Forum》2001,63(3):305-320
We consider some conditions guaranteeing that an unbounded operator is a generator of some strongly continuous group satisfying
a polynomial growth condition. The result is applied to a Friedrichs model given by Tf(x)=xf(x)+<f,ϕ>ψ (x) and considered as an operator in L
p
(R). Some sufficient condition on ϕ and ψ are found such that iT generates an example of a group with polynomial growth.
April 30, 1999 相似文献
10.
Roman A. Polyak 《Computational Optimization and Applications》2006,35(3):347-373
A class Ψ of strictly concave and twice continuously differentiable functions ψ: R → R with particular properties is used for constraint transformation in the framework of a Nonlinear Rescaling (NR) method with
“dynamic” scaling parameter updates. We show that the NR method is equivalent to the Interior Quadratic Prox method for the
dual problem in a rescaled dual space.
The equivalence is used to prove convergence and to estimate the rate of convergence of the NR method and its dual equivalent
under very mild assumptions on the input data for a wide class Ψ of constraint transformations. It is also used to estimate
the rate of convergence under strict complementarity and under the standard second order optimality condition.
We proved that for any ψ ∈ Ψ, which corresponds to a well-defined dual kernel ϕ = −ψ*, the NR method applied to LP generates
a quadratically convergent dual sequence if the dual LP has a unique solution.
This paper is dedicated to Professor Elijah Polak on the occasion of his 75th birthday. 相似文献
11.
Mats Andersson 《Mathematische Zeitschrift》2006,254(2):315-332
Let f be a r×m-matrix of holomorphic functions that is generically surjective. We provide explicit integral representation of holomorphic
ψ such that ϕ=f
ψ, provided that ϕ is holomorphic and annihilates a certain residue current with support on the set where f is not surjective. We also consider formulas for interpolation. As applications we obtain generalizations of various results
previously known for the case r=1.
The author was partially supported by the Swedish Research Council 相似文献
12.
In this paper the characterizations of conjugate hulls ψ (S). ϕ(S),T(S) and θ(S) on a Brandt semigroupS are given. By using these results we can pro thatT(S) is self-conjugate in ψ(S) for a Brandt semigroupS.
This work is supported by National Natural Science Foundation of China 相似文献
13.
Dimitrios A. Kandilakis Nikolaos S. Papageorgiou 《Proceedings Mathematical Sciences》1998,108(2):179-187
In this paper we examine nonlinear parabolic problems with a discontinuous right hand side. Assuming the existence of an upper
solution φ and a lower solution ψ such that ψ ≤ φ, we establish the existence of a maximum and a minimum solution in the order
interval [ψ, φ]. Our approach does not consider the multivalued interpretation of the problem, but a weak one side “Lipschitz”
condition on the discontinuous term. By employing a fixed point theorem for nondecreasing maps, we prove the existence of
extremal solutions in [ψ, φ for the original single valued version of the problem. 相似文献
14.
R. Warlimont 《manuscripta mathematica》1991,71(1):197-221
The quantities ψ(x, y), ϕ(x, y) which denote the number of positive integers ≤x without prime divisors >y,<y respectively as well as the concept of a set of multiples within ℕ together with many wellknown results on these have their
counterpart in arithmetical semigroups. 相似文献
15.
George F. McNulty 《Algebra Universalis》1982,15(1):115-125
For countable languages, we completely describe those cardinals κ such that there is an equational theory which covers exactly
κ other equational theories. For this task understanding term finite theories is helpful. A theoryT isterm finite provided {ψ:Tτϕ≈ψ} is finite for all terms ϕ. We develop here some fundamental properties of term finite theories and use them, together
with Ramsey's Theorem, to prove that any finitely based term finite theory covers only finitely many others. We also show
that every term finite theory possesses an independent base and that there are
such theories whose pairwise joins are not term finite.
The paper was written with the support of NSF Grant MCS-80-01778.
Presented by B. Jónsson. Received July 22, 1980. Accepted for publication in final form March 19, 1981. 相似文献
16.
This paper introduces a projection subgradient system modeled by an evolution differential inclusion to solve a class of hierarchical
optimization problems in Hilbert space. Basing on the Moreau–Yosida approximation, we prove the global existence and uniqueness
of the solution of the proposed evolution differential inclusion with projection and the unique solution of the proposed system
is just its “slow solution” when the constrained set is defined by the affine equalities. When the outer layer objective function
ψ is strongly convex, any solution of the proposed system is strongly convergent to the unique minimizer of the constrained
optimization problem, while, the strongly convergence is also given when the inner layer objective function ϕ is strongly convex. Furthermore, we present some other optimization problem models, which can be solved by the proposed system.
All the results obtained are new not only in the infinite dimensional Hilbert space framework but also in the finite dimensional
space. 相似文献
17.
Tommy Norberg 《Israel Journal of Mathematics》1992,77(3):241-264
Letψ andϕ be two given random closed sets in a locally compact second countable topological spaceS. (They need not be based on the same probability space.) The main result gives necessary and sufficient conditions on the
distributions ofψ andϕ, for the existence of two random closed sets
and
, based on the same probability space and such that their distributions coincide with those ofψ andϕ, resp., and
a.s.
This coupling result tells us in particular when a probability distribution onS is selectionable w.r.t. (the distribution of) a random closed set. An existence result for realizable thinnings of a simple
point process is obtained by specializing it to supports of random measures.
The coupling result is extended to random variables in a countably based continuous poset. As examples we mention various
kinds of random capacities — in particular random measures — and random compact (saturated) sets. Moreover, the extended result
tells us when a probability distribution onS is selectionable w.r.t. the distribution of a random compact (saturated) set. 相似文献
18.
Let λ and μ be solid sequence spaces. For a sequence of modulus functions Φ = (ϕ k) let λ(Φ) = {x = (x
k
): (ϕk(|x
k
|)) ∈ λ}. Given another sequence of modulus functions Ψ = (ψk), we characterize the continuity of the superposition operators P
f
from λ(Φ) into μ (Ψ) for some Banach sequence spaces λ and μ under the assumptions that the moduli ϕk (k ∈ ℕ) are unbounded and the topologies on the sequence spaces λ(Φ) and μ(Ψ) are given by certain F-norms. As applications
we consider superposition operators on some multiplier sequence spaces of Maddox type.
This research was supported by Estonian Science Foundation Grant 5376. 相似文献
19.
Using the theory of BL-algebras, it is shown that a propositional formula ϕ is derivable in Łukasiewicz infinite valued Logic
if and only if its double negation ˜˜ϕ is derivable in Hájek Basic Fuzzy logic. If SBL is the extension of Basic Logic by
the axiom (φ & (φ→˜φ)) → ψ, then ϕ is derivable in in classical logic if and only if ˜˜ ϕ is derivable in SBL. Axiomatic extensions
of Basic Logic are in correspondence with subvarieties of the variety of BL-algebras. It is shown that the MV-algebra of regular
elements of a free algebra in a subvariety of BL-algebras is free in the corresponding subvariety of MV-algebras, with the
same number of free generators. Similar results are obtained for the generalized BL-algebras of dense elements of free BL-algebras.
Received: 20 June 2001 /
Published online: 2 September 2002
This paper was prepared while the first author was visiting the Universidad de Barcelona supported by INTERCAMPUS Program
E.AL 2000. The second author was partially supported by Grants 2000SGR-0007 of D. G. R. of Generalitat de Catalunya and PB
97-0888 of D. G. I. C. Y. T. of Spain.
Mathematics Subject classification (2000): 03B50, 03B52, 03G25, 06D35
Keywords or Phrases: Basic fuzzy logic – Łukasiewicz logic – BL-algebras – MV-algebras – Glivenko's theorem 相似文献
20.
Rapha?l Lachièze-Rey 《Journal of Theoretical Probability》2012,25(2):313-332
The asymptotic solution of the inviscid Burgers equations with initial potential ψ is closely related to the convex hull of the graph of ψ. 相似文献