scholarly journals Breakable Semihypergroups

Symmetry ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 100 ◽  
Author(s):  
Dariush Heidari ◽  
Irina Cristea
Keyword(s):  
Nonempty Subset ◽  
Classical Case ◽  
Natural Generalization ◽  
Extended Version ◽  
Simple Property

In this paper, we introduce and characterize the breakable semihypergroups, a natural generalization of breakable semigroups, defined by a simple property: every nonempty subset of them is a subsemihypergroup. Then, we present and discuss on an extended version of Rédei’s theorem for semi-symmetric breakable semihypergroups, proposing a different proof that improves also the theorem in the classical case of breakable semigroups.

scholarly journals ON THE NATURE OF A CLASSICAL PSEUDODIFFERENTIAL EQUATION

2020 ◽  
Vol 8 (2) ◽  
pp. 83-92
Author(s):  
V. Litovchenko
Keyword(s):  
Cauchy Problem ◽  
Fundamental Solution ◽  
Moving Objects ◽  
Classical Case ◽  
Random Processes ◽  
Natural Generalization ◽  
General Nature ◽  
Pseudodifferential Equation ◽  
Fractional Differentiation ◽  
The Cauchy Problem

The work is devoted to the study of the general nature of one classical parabolic pseudodi- fferential equation with the operator M.Rice of fractional differentiation. At the corresponding values of the order of fractional differentiation, this equation is also known as the isotropic superdiffusion equation. It is a natural generalization of the classical diffusion equation. It is also known that the fundamental solution of the Cauchy problem for this equation is the density distribution of probabilities of stable symmetric random processes by P.Levy. The paper shows that the fundamental solution of this equation is the distribution of probabilities of the force of local influence of moving objects in a nonstationary gravitational field, in which the interaction between masses is subject to the corresponding potential of M.Rice. In this case, the classical case of Newton’s gravity corresponds to the known nonstationary J.Holtsmark distribution.

scholarly journals Tensor Product Structure of Affine Demazure Modules and Limit Constructions

2006 ◽  
Vol 182 ◽  
pp. 171-198 ◽  
Author(s):  
G. Fourier ◽  
P. Littelmann
Keyword(s):  
Tensor Product ◽  
Dynkin Diagram ◽  
Classical Case ◽  
Natural Generalization ◽  
Classical Type ◽  
Module Structure ◽  
Product Decomposition ◽  
Finite Dimensional ◽  
Demazure Modules ◽  
Extended Dynkin Diagram

AbstractLet g be a simple complex Lie algebra, we denote by ĝ the affine Kac-Moody algebra associated to the extended Dynkin diagram of g. Let Λ0 be the fundamental weight of ĝ corresponding to the additional node of the extended Dynkin diagram. For a dominant integral g-coweight λ∨, the Demazure submodule V_λ∨ (mΛ0) is a g-module. We provide a description of the g-module structure as a tensor product of “smaller” Demazure modules. More precisely, for any partition of λ∨ = λ∑j as a sum of dominant integral g-coweights, the Demazure module is (as g-module) isomorphic to ⊗jV_ (mΛ0). For the “smallest” case, λ∨ = ω∨ a fundamental coweight, we provide for g of classical type a decomposition of V_ω∨(mΛ0) into irreducible g-modules, so this can be viewed as a natural generalization of the decomposition formulas in [13] and [16]. A comparison with the Uq(g)-characters of certain finite dimensional -modules (Kirillov-Reshetikhin-modules) suggests furthermore that all quantized Demazure modules V_λ∨,q(mΛ0) can be naturally endowed with the structure of a -module. We prove, in the classical case (and for a lot of non-classical cases), a conjecture by Kashiwara [10], that the “smallest” Demazure modules are, when viewed as g-modules, isomorphic to some KR-modules. For an integral dominant ĝ-weight Λ let V(Λ) be the corresponding irreducible ĝ-representation. Using the tensor product decomposition for Demazure modules, we give a description of the g-module structure of V(Λ) as a semi-infinite tensor product of finite dimensional g-modules. The case of twisted affine Kac-Moody algebras can be treated in the same way, some details are worked out in the last section.

scholarly journals The Classical N-body Problem in the Context of Curved Space

2017 ◽  
Vol 69 (4) ◽  
pp. 790-806 ◽  
Author(s):  
Florin Diacu
Keyword(s):  
Gaussian Curvature ◽  
Body Problem ◽  
Equations Of Motion ◽  
Classical Case ◽  
Natural Generalization ◽  
First Integrals ◽  
Euclidean Case ◽  
Constant Gaussian Curvature ◽  
Curved Space ◽  
N Body Problem

AbstractWe provide the differential equations that generalize the Newtonian N-body problem of celestial mechanics to spaces of constant Gaussian curvature κ, for all κ ∊ ℝ. In previous studies, the equations of motion made sense only for κ ≠ 0. The system derived here does more than just include the Euclidean case in the limit κ → 0; it recovers the classical equations for κ = 0. This new expression of the laws of motion allows the study of the N-body problem in the context of constant curvature spaces and thus oòers a natural generalization of the Newtonian equations that includes the classical case. We end the paper with remarks about the bifurcations of the first integrals.

On mappings with finite length distortion on Riemann surfaces

2019 ◽  
Vol 33 ◽  
Author(s):  
Serhii Volkov ◽  
Vladimir Ryazanov
Keyword(s):  
Finite Length ◽  
Riemann Surfaces ◽  
Boundary Behavior ◽  
Main Tool ◽  
Natural Generalization ◽  
Finite Distortion ◽  
Lipschitz Mappings ◽  
Geometric Function ◽  
Mappings With Finite Distortion ◽  
Length Distortion

The present paper is a natural continuation of our previous paper (2017) on the boundary behavior of mappings in the Sobolev classes on Riemann surfaces, where the reader will be able to find the corresponding historic comments and a discussion of many definitions and relevant results. The given paper was devoted to the theory of the boundary behavior of mappings with finite distortion by Iwaniec on Riemannian surfaces first introduced for the plane in the paper of Iwaniec T. and Sverak V. (1993) On mappings with integrable dilatation and then extended to the spatial case in the monograph of Iwaniec T. and Martin G. (2001) devoted to Geometric function theory and non-linear analysis. At the present paper, it is developed the theory of the boundary behavior of the so--called mappings with finite length distortion first introduced in the paper of Martio O., Ryazanov V., Srebro U. and Yakubov~E. (2004) in the spatial case, see also Chapter 8 in their monograph (2009) on Moduli in modern mapping theory. As it was shown in the paper of Kovtonyuk D., Petkov I. and Ryazanov V. (2017) On the boundary behavior of mappings with finite distortion in the plane, such mappings, generally speaking, are not mappings with finite distortion by Iwaniec because their first partial derivatives can be not locally integrable. At the same time, this class is a generalization of the known class of mappings with bounded distortion by Martio--Vaisala from their paper (1988). Moreover, this class contains as a subclass the so-called finitely bi-Lipschitz mappings introduced for the spatial case in the paper of Kovtonyuk D. and Ryazanov V. (2011) On the boundary behavior of generalized quasi-isometries, that in turn are a natural generalization of the well-known classes of bi-Lipschitz mappings as well as isometries and quasi-isometries. In the research of the local and boundary behavior of mappings with finite length distortion in the spatial case, the key fact was that they satisfy some modulus inequalities which was a motivation for the consideration more wide classes of mappings, in particular, the Q-homeomorphisms (2005) and the mappings with finite area distortion (2008). Hence it is natural that under the research of mappings with finite length distortion on Riemann surfaces we start from establishing the corresponding modulus inequalities that are the main tool for us. On this basis, we prove here a series of criteria in terms of dilatations for the continuous and homeomorphic extension to the boundary of the mappings with finite length distortion between domains on arbitrary Riemann surfaces.

A Relative Notion of Natural Generalization

1975 ◽  
Vol 42 (1) ◽  
pp. 46-48 ◽  
Author(s):  
Nathan Stemmer
Keyword(s):  
Natural Generalization ◽  
Relative Notion
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