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fountain-Gould Left Orders for Associative Pairs

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Acta Mathematica Sinica,English Series 2006年第3期22卷 641-652页

作者： José A.ANQUELA Teresa CORTS Miguel GóMEZ LOZANO Mercedes SILES MOLINA departamento de matemáticas Universidad de Oviedo departamentode lgebra Geometríay TopologíaFacultad de CienciasUniversidad de MálagaCampus de Teatinos29071 MálagaSpain

In this paper, we introduce a notion of weak fountain-Gould left order for associative pairs and give a Goldie-like theory of associative pairs which are weak fountain Gould left orders in semiprime pairs coinciding w... 详细信息

关键词： fountain-Gould left order Associtive pair Goldie theory

On generalized impulsive piecewise constant delay differential equations

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Science China Mathematics 2015年第9期58卷 1981-2002页

作者： CHIU Kuo-Shou departamento de matemtica Facultad de Ciencias Bsicas Universidad Metropolitana de Ciencias de la Educación

A variation of parameters formula with Green function type and Gronwall type integral inequality are proved for impulsive differential equations involving piecewise constant delay of generalized type. Some results for piecewise constant linear and nonlinear delay differential equations with impulsive effects are *** include existence and uniqueness theorems, a variation of parameters formula, integral inequalities, the oscillation property and some applications.

关键词：脉冲微分方程常微分方程广义非线性时滞微分方程积分不等式分片分段线性唯一性定理

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On α-Weyl Operators

Advances in Pure Mathematics 2016年第3期6卷 138-143页

作者： Slaviša V. Djordjević fernando Hernández-Díaz facultad de ciencias físico-matemáticas BUAP Río Verde Puebla México

The purpose of this article is to present Schechter’s manner to introduce α-Wayl operators and compare this definition with another one given by Yadav and Arora. Moreover, we introduce generalized Weyl operator in t... 详细信息

关键词： fredholm Operators α-Closed Subspaces α-Weyl Operators

A charged star with geometric Karmarkar condition

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Communications in Theoretical Physics 2023年第8期75卷 139-149页

作者： Gabino Estevez-delgado Joaquin Estevez-delgado Rafael Soto-Espitia Antonio Rendón Romero Jorge Mauricio Paulin-fuentes facultad de Químico farmacobiología de la Universidad Michoacana de San Nicolás de Hidalgo facultad de ciencias físico matemáticas de la Universidad Michoacana de San Nicolás de Hidalgo Edificio BCiudad Universitaria facultad de Ingeniería Civil de la Universidad Michoacana de San Nicolás de Hidalgo Edificio A Ciudad Universitaria facultad de Ingeniería Mecánica de la Universidad Michoacana de San Nicolás de Hidalgo Edificio W Ciudad Universitaria División Académica de ciencias Básicas de la Universidad Juárez Autónoma de Tabasco

In this paper,we analyse an analytical solution of the Einstein–Maxwell field equations that considers matter with anisotropic pressures in a static and spherically symmetric *** report the manner in which we obtained the solution,which is by means of the Karmarkar *** the model,we assume a state equation that describes the interaction of matter from quarks P=(c^(2)ρ-4B_(g))/3 and we consider the presence of electric charge,which can generate that the radial and tangential pressures are not *** a graphic manner,we analyse the physical properties of the model,taking as the observational data those of mass 1M⊙and radius7.69 km which were reported for the star Her *** charge values are found between 5.57×10^(18)C≤Q≤1.31×10^(20)C and the interval of the Bag constant Bg∈[118.7,122.13]MeV/fm^(3).Also,we show the stability of the configuration by means of the static stability criteria of Harrison–Zeldovich–Novikov((?M)/?ρc>0),as well as in regards to infinitesimal radial adiabatic perturbation,since the adiabatic indexγ>3.3 which guarantees the stability of the solution.

关键词： general relativity exact solutions anisotropic fluid Karmarkar condition

Superattracting cycles for some Newton type iterative methods

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Science China Mathematics 2011年第3期54卷 539-544页

作者： AMAT Sergio BUSQUIER Sonia NAVARRO Emilie PLAZA Sergio departamento de matemtica Aplicada y Estadistica Universidad Politécnica de Cartagena Ecole Généraliste d'Ingénieurs de Marseille (EGIM) departamento de matemticas Facultad de Ciencias Universidad de Santiago de Chile

The paper is devoted to the analysis of certain dynamical properties of a family of iterative Newton type methods used to find roots of non-linear equations. We present a procedure for constructing polynomials in such a way that superattracting cycles of any prescribed length occur when these iterative methods are applied. This paper completes the study begun in Amat, Bermúclez, Busquier, et al., (2009).

关键词：牛顿迭代法周期动力特性分析迭代方法方程根非线性多项式

A solution to Tingley's problem for isometries between the unit spheres of compact C~*-algebras and JB~*-triples

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Science China Mathematics 2019年第3期62卷 553-568页

作者： Antonio M.Peralta Ryotaro Tanaka departamento de Ana'lisis matem'atico Facultad de Ciencias Universidad de Granada faculty of Mathematics Kyushu University

Let f : S(E) → S(B) be a surjective isometry between the unit spheres of two weakly compact JB*-triples not containing direct summands of rank less than or equal to 3. Suppose E has rank greater than or equal to 5. Applying techniques developed in JB*-triple theory, we prove that f admits an extension to a surjective real linear isometry T : E → B. Among the consequences, we show that every surjective isometry between the unit spheres of two compact C*-algebras A and B, without assuming any restriction on the rank of their direct summands(and in particular when A = K(H) and B = K(H′)), extends to a surjective real linear isometry from A into B. These results provide new examples of infinite-dimensional Banach spaces where Tingley's problem admits a positive answer.

关键词： Tingley’s problem extension of isometries JB*-triples compact operators

Cosmological Duality in four Time and four Space Dimensions

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Journal of Modern Physics 2021年第7期12卷 1027-1039页

作者： M. Medina J. A. Nieto P. A. Nieto-Marín facultad de ciencias físico-matemáticas de la Universidad Autónoma de Sinaloa Culiacán Sinaloa México

We describe a duality transformation in a cosmological model of four time and four space dimensions ((4 + 4)-dimensions). In particular, we show that via the fourier transform, at the level of the zero-point energy of quantum mechanics and the de Sitter space, a Gaussian distribution in four dimensions leads to a dual Gaussian distribution also in four dimensions, with duality transformation , in the standard deviation σ. Moreover, we show that as a consequence of such a duality in σ a duality of the cosmological constant Λ can be obtained. finally, we comment on the possibility that both the oriented matroid theory as well as the surreal number theory are related to the formalism presented in this work.

关键词： Cosmology (4 + 4)-Dimensional Gravitational Theory Classical and Quantum Gravity

Anisotropic stellar structure equations for magnetized strange stars

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Research in Astronomy and Astrophysics 2015年第7期15卷 975-985页

作者： Daryel Manreza Paret Jorge Ernesto Horvath Aurora Pérez Mart'nez departamento de f'sica General Facultad de F'sica Universidad de la Habana Instituto de Astronomia Geofisica e Ciencias Atmosfericas USP Instituto de Cibernética Matemática y Física (ICIMAF)

The fact that a fermion system in an external magnetic field breaks the spherical symmetry suggests that its intrinsic geometry is axisymmetric rather than spherical. In this work we analyze the impact of anisotropic pressures, due to the presence of a magnetic field, in the structure equations of a magnetized quark *** assume a cylindrical metric and an anisotropic energy momentum tensor for the source. We found that there is a maximum magnetic field that a strange star can sustain, closely related to the violation of the virial relations.

关键词： magnetic fields -- stars: neutron -- equation of state

Periodic Solutions in Unbounded Domains for the Boussinesq System

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Acta Mathematica Sinica,English Series 2010年第5期26卷 837-862页

作者： Elder Jesús VILLAMIZAR-ROA María ngeles RODRíGUEZ-BELLIDO Marko Antonio ROJAS-MEDAR Escuela de matemáticas Universidad Nacional de Colombia Dpto. Ecuaciones Diferenciales y Análisis Numérico Universidad de Sevilla Aptdo Dpto. de ciencias Básicas Facultad de Ciencias Universidad del Bío BíoCampus Fernando May

Assuming that the external forces of the system are small enough, the reference temperature being a periodic function, we study the existence, the uniqueness and the regularity of time-periodic solutions for the Boussinesq equations in several classes of unbounded domains of Rn. Our analysis is based on the framework of weak-Lp spaces.

关键词： Boussinesq equations strong periodic solutions unbounded domains