期刊文献+
共找到50篇文章
< 1 2 3 >
每页显示 20 50 100
A MULTIDIMENSIONAL CENTRAL LIMIT THEOREM WITH SPEED OF CONVERGENCE FOR AXIOM A DIFFEOMORPHISMS
1
作者 夏红强 檀大耀 《Acta Mathematica Scientia》 SCIE CSCD 2011年第3期1123-1132,共10页
Let T:X → X be an Axiom A diffeomorphism,m the Gibbs state for a Hlder continuous function ɡ. Assume that f:X → R^d is a Hlder continuous function with ∫_X^(fdm) = 0.If the components of f are cohomologously i... Let T:X → X be an Axiom A diffeomorphism,m the Gibbs state for a Hlder continuous function ɡ. Assume that f:X → R^d is a Hlder continuous function with ∫_X^(fdm) = 0.If the components of f are cohomologously independent, then there exists a positive definite symmetric matrix σ~2:=σ~2 (f ) such that S^fn √ n converges in distribution with respect to m to a Gaussian random variable with expectation 0 and covariance matrix σ~2 . Moreover, there exists a real number A 〉 0 such that, for any integer n ≥ 1,Π( m*( 1√ nS f n ),N (0,σ~2 ) ≤A√n, where m*(1√ n S^fn)denotes the distribution of 1√ n S^fn with respect to m, and Π is the Prokhorov metric. 展开更多
关键词 multidimensional central limit theorem Axiom A diffeomorphisms symbolic dynamics transfer operator
下载PDF
A Renormalizable Theory of Quantum Gravity: Renormalization Proof of the Gauge Theory of Volume Preserving Diffeomorphisms
2
作者 Christian Wiesendanger 《Journal of Modern Physics》 2014年第10期959-983,共25页
Inertial and gravitational mass or energy momentum need not be the same for virtual quantum states. Separating their roles naturally leads to the gauge theory of volume-preserving diffeomorphisms of an inner four-dime... Inertial and gravitational mass or energy momentum need not be the same for virtual quantum states. Separating their roles naturally leads to the gauge theory of volume-preserving diffeomorphisms of an inner four-dimensional space. The gauge-fixed action and the path integral measure occurring in the generating functional for the quantum Green functions of the theory are shown to obey a BRST-type symmetry. The related Zinn-Justin-type equation restricting the corresponding quantum effective action is established. This equation limits the infinite parts of the quantum effective action to have the same form as the gauge-fixed Lagrangian of the theory proving its spacetime renormalizability. The inner space integrals occurring in the quantum effective action which are divergent due to the gauge group’s infinite volume are shown to be regularizable in a way consistent with the symmetries of the theory demonstrating as a byproduct that viable quantum gauge field theories are not limited to finite-dimensional compact gauge groups as is commonly assumed. 展开更多
关键词 RENORMALIZATION PROOF of GAUGE Field THEORY of Volume-Preserving diffeomorphisms
下载PDF
LOCAL CENTRAL LIMIT THEOREM AND BERRY-ESSEEN THEOREM FOR SOME NONUNIFORMLY HYPERBOLIC DIFFEOMORPHISMS 被引量:1
3
作者 夏红强 《Acta Mathematica Scientia》 SCIE CSCD 2010年第3期701-712,共12页
We prove that, for non-uniformly hyperbolic diffeomorphisms in the sense of Young, the local central limit theorem holds, and the speed in the central limit theorem is O(1/√n).
关键词 Local central limit theorem Berry-Esseen theorem nonuniform hyperbolic diffeomorphism Henon map
下载PDF
General Relativity as the Classical Limit of the Renormalizable Gauge Theory of Volume Preserving Diffeomorphisms
4
作者 Christian Wiesendanger 《Journal of Modern Physics》 2014年第10期948-958,共11页
The different roles and natures of spacetime appearing in a quantum field theory and in classical physics are analyzed implying that a quantum theory of gravitation is not necessarily a quantum theory of curved spacet... The different roles and natures of spacetime appearing in a quantum field theory and in classical physics are analyzed implying that a quantum theory of gravitation is not necessarily a quantum theory of curved spacetime. Developing an alternative approach to quantum gravity starts with the postulate that inertial energy-momentum and gravitational energy-momentum need not be the same for virtual quantum states. Separating their roles naturally leads to the quantum gauge field theory of volume-preserving diffeomorphisms of an inner four-dimensional space. The classical limit of this theory coupled to a quantized scalar field is derived for an on-shell particle where inertial energy-momentum and gravitational energy-momentum coincide. In that process the symmetry under volume-preserving diffeomorphisms disappears and a new symmetry group emerges: the group of coordinate transformations of four-dimensional spacetime and with it General Relativity coupled to a classical relativistic point particle. 展开更多
关键词 QUANTUM Gravity QUANTUM Gauge Theory of Volume-Preserving DIFFEOMORPHISM Group GR Emerging AS the Classical LIMIT of Above Different Roles of Inertial and Gravitational Momentum Observability of Spacetime at Microscopic Level
下载PDF
Quasisymmetric property for conjugacies between Anosov diffeomorphisms of the two-torus
5
作者 HU HuYi 1 & JIANG YunPing 2, 1 Department of Mathematics, Michigan State University, East Lansing, MI 48824, USA 2 Department of Mathematics, the Graduate Center and Queens College of CUNY, Flushing, NY 11367, USA 《Science China Mathematics》 SCIE 2010年第3期663-670,共8页
We prove that the restrictions of the conjugacy between two Anosov diffeomorphisms of the twotorus to the stable and unstable manifolds are quasisymmetric homeomorphisms.
关键词 quasisymmetry Anosov diffeomorphisms CONJUGACY Hlder condition MARKOV PARTITION
原文传递
Centralizers and Iterate Radicals of Morse-Smale Diffeomorphisms of the Circle
6
作者 Zhang Meirong Department of Applied Mathematics Tsinghua University Beijing,100084 China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 1995年第1期1-11,共11页
In this paper,we will use the embedding flows in[1],[2]to give a complete descrip- tion of the smooth centralizers and iterate radicals of all C^r(r≥2)Morse-Smale diffeomorphisms of the circle S^1.As a result,we prov... In this paper,we will use the embedding flows in[1],[2]to give a complete descrip- tion of the smooth centralizers and iterate radicals of all C^r(r≥2)Morse-Smale diffeomorphisms of the circle S^1.As a result,we prove that every centralizer is a solvable subgroup of Diff^r(S^1). 展开更多
关键词 Centralizers and Iterate Radicals of Morse-Smale diffeomorphisms of the Circle TDFs
原文传递
Ashtekar-Kodama Gravity as a Classical and Quantum Extension of Loop Quantum Gravity
7
作者 Jan Helm 《Journal of Modern Physics》 2024年第6期864-937,共74页
This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and i... This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and in the quantum regime a full renormalizable quantum gauge field theory. The three fundamental constraints (hamiltonian, gaussian and diffeomorphism) were formulated in 3-dimensional spatial form within LQG in Ashtekar formulation using the notion of the Kodama state with positive cosmological constant Λ. We introduce a 4-dimensional covariant version of the 3-dimensional (spatial) hamiltonian, gaussian and diffeomorphism constraints of LQG. We obtain 32 partial differential equations for the 16 variables E<sub>mn</sub> (E-tensor, inverse densitized tetrad of the metric) and 16 variables A<sub>mn</sub> (A-tensor, gravitational wave tensor). We impose the boundary condition: for large distance the E-generated metric g(E) becomes the GR-metric g (normally Schwarzschild-spacetime). The theory based on these Ashtekar-Kodama (AK) equations, and called in the following Ashtekar-Kodama (AK-) gravity has the following properties. • For Λ = 0 the AK equations become Einstein equations, A-tensor is trivial (constant), and the E-generated metric g(E) is identical with the GR-metric g. • When the AK-equations are developed into a Λ-power series, the Λ-term yields a gravitational wave equation, which has only at least quadrupole wave solutions and becomes in the limit of large distance r the (normal electromagnetic) wave equation. • AK-gravity, as opposed to GR, has no singularity at the horizon: the singularity in the metric becomes a (very high) peak. • AK-gravity has a limit scale of the gravitational quantum region 39 μm, which emerges as the limit scale in the objective wave collapse theory of Gherardi-Rimini-Weber. In the quantum region, the AK-gravity becomes a quantum gauge theory (AK quantum gravity) with the Lie group extended SU(2) = ε-tensor-group(four generators) as gauge group and a corresponding covariant derivative. • AK quantum gravity is fully renormalizable, we derive its Lagrangian, which is dimensionally renormalizable, the normalized one-graviton wave function, the graviton propagator, and demonstrate the calculation of cross-section from Feynman diagrams. 展开更多
关键词 Quantum Gravity Loop Quantum Gravity General Relativity Gravitational Wave Gauge Field Theory Graviton Hamiltonian Constraint Gaussian Constraint Diffeomorphism Constraint
下载PDF
EMBEDDING FLOWS OF DIFFEOMORPHISMS
8
作者 Yangyou Pan Xiang Zhang 《Annals of Differential Equations》 2014年第2期166-173,共8页
In this paper we first survey the results on the embedding flow problem of dif-feomorphisms in higher dimensional spaces. Next we present some new results on the characterization of semi-unipotent diffeomorphisms in R... In this paper we first survey the results on the embedding flow problem of dif-feomorphisms in higher dimensional spaces. Next we present some new results on the characterization of semi-unipotent diffeomorphisms in R3, which have a formal embedding flows. 展开更多
关键词 diffeomorphisms embedding vector field normal form
原文传递
Kobayashi’s and Teichmuller’s Metrics and Bers Complex Manifold Structure on Circle Diffeomorphisms 被引量:1
9
作者 Yun Ping JIANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2020年第3期245-272,共28页
Given a modulus of continuity ω,we consider the Teichmuller space TC1+ω as the space of all orientation-preserving circle diffeomorphisms whose derivatives are ω-continuous functions modulo the space of Mobius tran... Given a modulus of continuity ω,we consider the Teichmuller space TC1+ω as the space of all orientation-preserving circle diffeomorphisms whose derivatives are ω-continuous functions modulo the space of Mobius transformations preserving the unit disk.We study several distortion properties for diffeomorphisms and quasisymmetric homeomorphisms.Using these distortion properties,we give the Bers complex manifold structure on the Teichm(u| ")ller space TC^1+H as the union of over all0 <α≤1,which turns out to be the largest space in the Teichmuller space of C1 orientation-preserving circle diffeomorphisms on which we can assign such a structure.Furthermore,we prove that with the Bers complex manifold structure on TC^1+H ,Kobayashi’s metric and Teichmuller’s metric coincide. 展开更多
关键词 Bers complex manifold STRUCTURE circle DIFFEOMORPHISM modulus of continuity quasisymmetric circle HOMEOMORPHISM Teichmuller space Kobayashi's METRIC Teichmuller's METRIC
原文传递
Diffeomorphisms with the M0-shadowing Property
10
作者 Xu ZHANG Xin Xing WU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2019年第11期1760-1770,共11页
This paper studies the M0-shadowing property for the dynamics of diffeomorphisms defined on closed manifolds. The C1 interior of the set of all two dimensional diffeomorphisms with the M0-shadowing property is describ... This paper studies the M0-shadowing property for the dynamics of diffeomorphisms defined on closed manifolds. The C1 interior of the set of all two dimensional diffeomorphisms with the M0-shadowing property is described by the set of all Anosov diffeomorphisms. The C1-stably M0-shadowing property on a non-trivial transitive set implies the diffeomorphism has a dominated splitting. 展开更多
关键词 Anosov DIFFEOMORPHISM AVERAGE SHADOWING PROPERTY Mα-shadowing
原文传递
Two Characterizations of Diffeomorphisms of Euclidean Space
11
作者 LiJunYANG XianWuZENG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2003年第4期739-744,共6页
Two characterizations for a local diffeomorphism of R^n to be global one aregiven in terms of associated Wazewski equations. The two characterizations could be useful for theinvestigation of the Jacobian conjecture.
关键词 COMPLETENESS DIFFEOMORPHISM Jacobian conjecture properness
原文传递
On the density of Birkhoff sums for Anosov diffeomorphisms
12
作者 Shaobo Gan Yi Shi Mingyang Xia 《Science China Mathematics》 SCIE CSCD 2022年第2期319-330,共12页
Let f : M → M be an Anosov diffeomorphism on a nilmanifold. We consider Birkhoff sums for a Holder continuous observation along periodic orbits. We show that if there are two Birkhoff sums distributed at both sides o... Let f : M → M be an Anosov diffeomorphism on a nilmanifold. We consider Birkhoff sums for a Holder continuous observation along periodic orbits. We show that if there are two Birkhoff sums distributed at both sides of zero, then the set of Birkhoff sums of all the periodic points is dense in R. 展开更多
关键词 Anosov diffeomorphism Birkhoff sum periodic point NILMANIFOLD
原文传递
Rigidity result on conjugacies of families of diffeomorphisms
13
作者 李伟固 章梅荣 《Science China Mathematics》 SCIE 1997年第10期1036-1044,共9页
Embedding flows are used to obtain a rigidity result on strongly topological conjugacy of families of diffeomorphisms,i.e.families of C4(2≤r≤∞) diffeomorphisms,the strongly topologically conjugating homeomor-phisms... Embedding flows are used to obtain a rigidity result on strongly topological conjugacy of families of diffeomorphisms,i.e.families of C4(2≤r≤∞) diffeomorphisms,the strongly topologically conjugating homeomor-phisms near degenerate saddle-nodes will be differentiable on center manifolds of the saddle-nodes. 展开更多
关键词 DIFFEOMORPHISM TOPOLOGICAL conjugacy.
原文传递
Diffeomorphisms with Lp-Shadowing Property
14
作者 Abbas FAKHARI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2011年第1期19-28,共10页
We give a characterization of structurally stable diffeomorphisms by making use of the notion of LP-shadowing property. More precisely, we prove that the set of structurally stable diffeomorphisms coincides with the C... We give a characterization of structurally stable diffeomorphisms by making use of the notion of LP-shadowing property. More precisely, we prove that the set of structurally stable diffeomorphisms coincides with the C1-interior of the set of diffeomorphisms having LP-shadowing property. 展开更多
关键词 LP-shadowing C1-interior structurally stable diffeomorphism
原文传递
On Local Constancy of Topological Entropy for Certain Partially Hyperbolic Diffeomorphisms
15
作者 Lin WANG Xin-sheng WANG Yu-jun ZHU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2018年第2期249-253,共5页
Let f : M → M be a partially hyperbolic diffeomorphism on a closed Riemannian manifold with uniformly compact center foliation. We show that if the center foliation of f is of dimension one then the topological entr... Let f : M → M be a partially hyperbolic diffeomorphism on a closed Riemannian manifold with uniformly compact center foliation. We show that if the center foliation of f is of dimension one then the topological entropy is constant on a small C1 neighborhood of f. 展开更多
关键词 partially hyperbolic diffeomorphism topological entropy local constancy
原文传递
Scattering Cross-Sections in Quantum Gravity—The Case of Matter-Matter Scattering
16
作者 Christian Wiesendanger 《Journal of Modern Physics》 2015年第3期273-282,共10页
Viewing gravitational energy-momentum PG<sup style='margin-left:-7px;'>μ as equal by observation, but different in essence from inertial energy-momentum PI<sup style='margin-left:-7px;'>μ... Viewing gravitational energy-momentum PG<sup style='margin-left:-7px;'>μ as equal by observation, but different in essence from inertial energy-momentum PI<sup style='margin-left:-7px;'>μ naturally leads to the gauge theory of volume-preserving diffeomorphisms of a four-dimensional inner space. To analyse scattering in this theory, the gauge field is coupled to two Dirac fields with different masses. Based on a generalized LSZ reduction formula the S-matrix element for scattering of two Dirac particles in the gravitational limit and the corresponding scattering cross-section are calculated to leading order in perturbation theory. Taking the non-relativistic limit for one of the initial particles in the rest frame of the other the Rutherford-like cross-section of a non-relativistic particle scattering off an infinitely heavy scatterer calculated quantum mechanically in Newtonian gravity is recovered. This provides a non-trivial test of the gauge field theory of volume-preserving diffeomorphisms as a quantum theory of gravity. 展开更多
关键词 Renormalizable QUANTUM GRAVITY SCATTERING CROSS-SECTIONS in QUANTUM GRAVITY Gauge Theory of Volume-Preserving diffeomorphisms
下载PDF
Conservation of Gravitational Energy Momentum and Renormalizable Quantum Theory of Gravitation
17
作者 Christian Wiesendanger 《Journal of Modern Physics》 2013年第8期133-152,共20页
Viewing gravitational energy-momentum as equal by observation, but different in essence from inertial energymomentum naturally leads to the gauge theory of volume-preserving diffeomorphisms of an inner Minkowski space... Viewing gravitational energy-momentum as equal by observation, but different in essence from inertial energymomentum naturally leads to the gauge theory of volume-preserving diffeomorphisms of an inner Minkowski space which can describe gravitation at the classical level. This theory is quantized in the path integral formalism starting with a non-covariant Hamiltonian formulation with unconstrained canonical field variables and a manifestly positive Hamiltonian. The relevant path integral measure and weight are then brought into a Lorentz- and gauge-covariant form allowing to express correlation functions—applying the De Witt-Faddeev-Popov approach—in any meaningful gauge. Next the Feynman rules are developed and the quantum effective action at one loop in a background field approach is renormalized which results in an asymptotically free theory without presence of other fields and in a theory without asymptotic freedom including the Standard Model (SM) fields. Finally the BRST apparatus is developed as preparation for the renormalizability proof to all orders and a sketch of this proof is given. 展开更多
关键词 Path Integral QUANTIZATION GAUGE Theory Volume-Preserving diffeomorphisms
下载PDF
Geometric Structures of Stable Time-Variant State Feedback Systems 被引量:2
18
作者 仲锋惟 孙华飞 张真宁 《Journal of Beijing Institute of Technology》 EI CAS 2007年第4期500-504,共5页
A new technique for considering the stabilizing time-variant state feedback gains is proposed from the viewpoint of information geometry. First, parametrization of the set of all stabilizing time-variant state feedbac... A new technique for considering the stabilizing time-variant state feedback gains is proposed from the viewpoint of information geometry. First, parametrization of the set of all stabilizing time-variant state feedback gains is given. Moreover, a diffeomorphic structure between the set of stabilizing time-variant state feedback gains and the Cartesian product of positive definite matrix and skew symmetric matrix satisfying certain algebraic conditions is constructed. Furthermore, an immersion and some results about the eigenvalue locations of stable state feedback systems are derived. 展开更多
关键词 geometric structure state feedback IMMERSION DIFFEOMORPHISM
下载PDF
Vacuum Black Hole Mass Formula Is a Vanishing Noether Charge 被引量:1
19
作者 WU Xiao-Ning GUO Han-Ying HUANG Chao-Guang WU Ke 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第9期309-312,共4页
The Noether current and its variation relation with respect to diffeomorphism invariance of gravitationaltheories have been derived from the horizontal variation and vertical-horizontal bi-variation of the Lagrangian,... The Noether current and its variation relation with respect to diffeomorphism invariance of gravitationaltheories have been derived from the horizontal variation and vertical-horizontal bi-variation of the Lagrangian, respec-tively. For Einstein's GR in the stationary, axisymmetric black holes, the mass formula in vacuum can be derived fromthis Noether current although it definitely vanishes. This indicates that the mass formula of black holes is a vanishingNoether charge in this case. The first law of black hole thermodynamics can also be derived from the variation relationof this vanishing Noether current. 展开更多
关键词 black hole mass formula NOETHER charge DIFFEOMORPHISM INVARIANCE
下载PDF
AUTOMATIC SEGMENTATION OF HIPPOCAMPAL SUBFIELDS BASED ON MULTI-ATLAS IMAGE SEGMENTATION TECHNIQUES 被引量:2
20
作者 Shi Yonggang Zhang Xueping Liu Zhiwen 《Journal of Electronics(China)》 2014年第2期121-128,共8页
The volume of hippocampal subfields is closely related with early diagnosis of Alzheimer's disease.Due to the anatomical complexity of hippocampal subfields,automatic segmentation merely on the content of MR image... The volume of hippocampal subfields is closely related with early diagnosis of Alzheimer's disease.Due to the anatomical complexity of hippocampal subfields,automatic segmentation merely on the content of MR images is extremely difficult.We presented a method which combines multi-atlas image segmentation with extreme learning machine based bias detection and correction technique to achieve a fully automatic segmentation of hippocampal subfields.Symmetric diffeomorphic registration driven by symmetric mutual information energy was implemented in atlas registration,which allows multi-modal image registration and accelerates execution time.An exponential function based label fusion strategy was proposed for the normalized similarity measure case in segmentation combination,which yields better combination accuracy.The test results show that this method is effective,especially for the larger subfields with an overlap of more than 80%,which is competitive with the current methods and is of potential clinical significance. 展开更多
关键词 Hippocampal subfields Image segmentation Symmetric diffeomorphism Mutual information Label fusion Extreme Learning Machine(ELM)
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部