共查询到20条相似文献,搜索用时 15 毫秒
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Yu. A. Neretin 《Functional Analysis and Its Applications》2016,50(2):160-162
It is shown that the group PSL2(?) is a spherical subgroup in the group of C3-diffeomorphisms of the circle. 相似文献
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We study the rate of convergence in von Neumann’s ergodic theorem. We obtain constants connecting the power rate of convergence of ergodic means and the power singularity at zero of the spectral measure of the corresponding dynamical system (these concepts are equivalent to each other). All the results of the paper have obvious exact analogs for wide-sense stationary stochastic processes. 相似文献
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This paper studies the dynamics implied by the Chamley (1993) model, a variant of the two-sector model with an implicit characterization of the learning function. We first show that under some “regularity” conditions regarding the learning function, the model has (a) one steady state, (b) no steady states or (c) two steady states (one saddle and one non-saddle). Moreover, via the Bogdanov–Takens theorem, we prove that for critical regions of the parameters space, the dynamics undergoes a particular global phenomenon, namely the homoclinic bifurcation. Because these findings imply the existence of a continuum of equilibrium trajectories, all departing from the same initial value of the predetermined variable, the model exhibits global indeterminacy. 相似文献
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P. S. Anisimov 《Theoretical and Mathematical Physics》2014,180(3):1005-1018
In the one-loop approximation for the modified Yang-Mills theory, we calculate contributions to the two- and three-point Green’s functions of the gauge field A μ , to the Green’s function of the anticommuting fields e and b, and to the vertex function Γ Aeb. We find the renormalization constants Z 1 and Z 2 and the corresponding constants \(\bar Z_1\) and \(\bar Z_2\) for the anticommuting fields and show that they satisfy the same equation as in the standard Yang-Mills theory. We demonstrate that the β-functions in the standard and modified theories coincide. 相似文献
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ExistenceoftheSelfSimilarSolutionsintheHeatFlowofHarmonicMapsFanHuijun(范辉军)(InstituteofMathematics,PekingUniversity,100871)C... 相似文献
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ZHENGHAI HUANG YUDA HU 《运筹学学报》1997,(2)
1.IntroductionTheclassicalworkOiltheoremsofthealternativeforsingle-valuedfunctionbyG..d..II]andMotzkin[2]wereextendbymanyresearchersinvariousways(suchasJeyakumar['l'],Lily],andTamminen[6]),whereconditionsofconvexityaremoreorlessrelaxed.Met's..rk[:]givesemphasistotheoremsofthealternativeinthesettingofset-valuedfunctionwhereconditionofconvexityissettobecone-convex.Thispaperaimsatprovidinganunifiedextensionoftheabove-mentionedtheorems,andgivesoutageneraltheoremofthealternativeinthecontextofset… 相似文献
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Hristo Iliev 《代数通讯》2013,41(4):1550-1564
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We consider the problem of a body moving within an incompressible fluid at constant speed parallel to a wall, in an otherwise
unbounded domain. This situation is modeled by the incompressible Navier–Stokes equations in an exterior domain in a half
space, with appropriate boundary conditions on the wall, the body, and at infinity. Here we prove existence of stationary
solutions for this problem for the simplified situation where the body is replaced by a source term of compact support. 相似文献
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Siberian Mathematical Journal - Given a nonempty set π of primes, call a nilpotent group π-bounded whenever it has a central series whose every factor F is such that: In every quotient... 相似文献
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《应用概率统计》1999,(3)
51.IntroductionTwo(parametersemi-martingaleswereinvestigated,forexample,inthepaperbyBrennan[21,Cairoli[3]andZakai[81.Inthispaperwegeneralizetheconceptofatwo-parametersemimartingaleandinvestigatesomepropertiesofthegeneralizedsemi-martingaoes.Wealsodefineaclassofpositivemeasuresassociatedwiththegeneralizedsemi-martingales.InSectionII,followingtheterminologygivenin[21,wedefinestrongandweakA--processesoforderp,alsofor15p相似文献
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Let Diffeo = Diffeo(ℝ) denote the group of infinitely differentiable diffeomorphisms of the real line ℝ, under the operation
of composition, and let Diffeo+ be the subgroup of diffeomorphisms of degree +1, i.e., orientation-preserving diffeomorphisms. We show how to reduce the
problem of determining whether or not two given elements f, g ∈ Diffeo are conjugate in Diffeo to associated conjugacy problems in the subgroup Diffeo+. The main result concerns the case when f and g have degree −1, and specifies (in an explicit and verifiable way) precisely what must be added to the assumption that their
(compositional) squares are conjugate in Diffeo+, in order to ensure that f is conjugated to g by an element of Diffeo+. The methods involve formal power series and results of Kopell on centralisers in the diffeomorphism group of a half-open
interval. Bibliography: 4 titles.
Published in Zapiski Nauchnykh Seminarov POMI, Vol. 360, 2008, pp. 231–237. 相似文献
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Mathematical Notes - The space of minimal energy of a qubit system is the dark subspace of quantum states of a system of two-level atoms in the finite-dimensional Tavis–Cummings (TC) model of... 相似文献
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Angelo Miele 《Journal of Optimization Theory and Applications》2010,147(3):483-490
On the occasion of the 50th anniversary of the theorem of the image trajectories in the Earth-Moon space, the author revisits
the theorem and clarifies the relation between the class of image trajectories and the class of symmetric free-return trajectories,
which were employed in the Apollo program. In a nutshell, the symmetric free-return trajectories are those image trajectories
that intersect the Earth-Moon axis orthogonally at some point above the far side of the Moon. Optimization implications are
pointed out. 相似文献
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For a large class of locally compact semitopological semigroups S, the Stone-Čech compactification β
S is a semigroup compactification if and only if S is either discrete or countably compact. Furthermore, for this class of semigroups which are neither discrete nor countably
compact, the quotient
contains a linear isometric copy of ℓ
∞. These results improve theorems by Baker and Butcher and by Dzinotyiweyi. 相似文献
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Ukrainian Mathematical Journal - The existence of holomorphic (in time) solutions of the nonrelativistic equations of motion of nonneutral systems of point charges that do not contain inverse... 相似文献
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Annie Burns-Childers Draga Vidakovic 《International Journal of Mathematical Education in Science & Technology》2018,49(5):660-679
The purpose of this study was to gain insight into 30, first year calculus students’ understanding of the relationship between the concept of vertex of a quadratic function and the concept of the derivative. APOS (action-process-object-schema) theory was applied as a guiding framework of analysis on student written work, think-aloud and follow up group interviews. Students’ personal meanings of the vertex, including misconceptions, were explored, along with students’ understanding to solve problems pertaining to the derivative of a quadratic function. Results give evidence of students’ weak schema of the vertex, lack of connection between different problem types and the importance of linguistics in relation to levels of APOS theory. A preliminary genetic decomposition was developed based on the results. Future research is suggested as a continuation to improve student understanding of the relationship between the vertex of quadratic functions and the derivative. 相似文献
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The Douglas–Rachford algorithm is a popular method for finding zeros of sums of monotone operators. By its definition, the Douglas–Rachford operator is not symmetric with respect to the order of the two operators. In this paper we provide a systematic study of the two possible Douglas–Rachford operators. We show that the reflectors of the underlying operators act as bijections between the fixed points sets of the two Douglas–Rachford operators. Some elegant formulae arise under additional assumptions. Various examples illustrate our results. 相似文献