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Space-Energy Duality Generalized 4-Index Einstein Field Equation
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作者 Mahgoub A. Salih 《International Journal of Astronomy and Astrophysics》 2023年第4期281-297,共17页
The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivat... The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivation of Einstein’s equations in the 4-index format. Additionally, a two-index field equation is presented, comprising a conventional Einstein field equation and a trace-free Einstein equation. Notably, the cosmological constant is associated with a novel concept that facilitates the encoding of space and energy information, thereby enabling the recognition of mutual interactions between space and energy in the presence of gravitational forces, as dictated by Einstein’s field equations (EFE) and Trace-Free Einstein Equation (TFE). 展开更多
关键词 einstein field equation Trace-Free einstein equation 4-Index Cosmological Constant
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Bach-Einstein Gravitational Field Equations as a Perturbation of Einstein Gravitational Field Equations
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作者 Fathy Ibrahim Abdel-Bassier Ahmed Fouad Abdel-Wahab Fayrouz Mostafa Abdel-Maboud 《Applied Mathematics》 2022年第12期1022-1032,共11页
The Bach equations are a version of higher-order gravitational field equations, exactly they are of fourth-order. In 4-dimensions the Bach-Einstein gravitational field equations are treated here as a perturbation of E... The Bach equations are a version of higher-order gravitational field equations, exactly they are of fourth-order. In 4-dimensions the Bach-Einstein gravitational field equations are treated here as a perturbation of Einstein’s gravity. An approximate inversion formula is derived which admits a comparison of the two field theories. An application to these theories is given where the gravitational Lagrangian is expressed linearly in terms of R, R<sup>2</sup>, |Ric|<sup>2</sup>, where the Ricci tensor Ric = R<sub>αβ</sub>dx<sup>α</sup>dx<sup>β</sup> is inserted in some formulas which are of geometrical or physical importance, such as;Raychaudhuri equation and Tolman’s formula. 展开更多
关键词 Gravitational Theory Higher Order Gravity Buchdahl’s Formula Bach-einstein Gravitational field equations Raychaudhuri equation Tolman’s Formula
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Time-Machine Solutions of Einstein's Equations with Electromagnetic Field
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作者 沈明 孙庆有 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第1期69-71,共3页
在这份报纸,我们在电磁的地里调查时间机器问题。基于是 Ori 的一张更一般的表格,我们为电磁的地与精力动量张肌解决爱因斯坦的方程,并且构造时间机器答案的一个度量标准,它在电磁的地里解决时间机器问题。
关键词 爱因斯坦方程 电磁场方程 时间机器 电磁场能量动量张量 一般形式
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Nonlinear Spinor Field Equations in Gravitational Theory: Spherical Symmetric Soliton-Like Solutions 被引量:2
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作者 V. Adanhounme A. Adomou +1 位作者 F. P. Codo M. N. Hounkonnou 《Journal of Modern Physics》 2012年第9期935-942,共8页
This paper deals with an extension of a previous work [Gravitation & Cosmology, Vol. 4, 1998, pp 107-113] to exact spherical symmetric solutions to the spinor field equations with nonlinear terms which are arbitra... This paper deals with an extension of a previous work [Gravitation & Cosmology, Vol. 4, 1998, pp 107-113] to exact spherical symmetric solutions to the spinor field equations with nonlinear terms which are arbitrary functions of S=ψψ, taking into account their own gravitational field. Equations with power and polynomial nonlinearities are studied in detail. It is shown that the initial set of the Einstein and spinor field equations with a power nonlinearity has regular solutions with spinor field localized energy and charge densities. The total energy and charge are finite. Besides, exact solutions, including soliton-like solutions, to the spinor field equations are also obtained in flat space-time. 展开更多
关键词 Lagrangian static sPHERICAL sYMMETRIC Metric field equations einstein equations Dirac equation ENERGY-MOMENTUM Tensor Charge Density Current Vector sOLITON-LIKE solution
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On Quasi-Einstein Field Equation
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作者 赵培标 杨孝平 《Northeastern Mathematical Journal》 CSCD 2005年第4期411-420,共10页
In this paper some properties of a symmetric tensor field T(X,Y) = g(A(X), Y) on a Riemannian manifold (M, g) without boundary which satisfies the S quasi-Einstein equation Rij-S/2gij=Tij+bξiξj are given. ... In this paper some properties of a symmetric tensor field T(X,Y) = g(A(X), Y) on a Riemannian manifold (M, g) without boundary which satisfies the S quasi-Einstein equation Rij-S/2gij=Tij+bξiξj are given. The necessary and sufficient conditions for this tensor to satisfy the quasi-Einstein equation are also obtained. 展开更多
关键词 einstein field equation quasi-einstein field equation Minkowski space Parallel field gravitational field “Ricci” symmetric tensor Lagrange equation
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On Maxwell Equations for Gravitational Field
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作者 Gustavo V. López 《Journal of Applied Mathematics and Physics》 2018年第4期932-947,共16页
For explicitly time depending mass density which satisfies a continuity equation, it is shown that Maxwell-like equations for gravitational field follow naturally without any need of General Relativity Theory approxim... For explicitly time depending mass density which satisfies a continuity equation, it is shown that Maxwell-like equations for gravitational field follow naturally without any need of General Relativity Theory approximation or related assumptions. As a consequence, it is shown that several features already known in Electrodynamics (Poynting vector, density of energy, tensor stress, and radiation) are totally reproduced for gravitational field. 展开更多
关键词 GRAVITATIONAL field Maxwell’s equations GRAVITATIONAL WAVEs GRAVITATIONAL RADIATION REACTION
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Theoretical Maxwell's Equations, Gauge Field and Their Universality Based on One Conservation Law
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作者 柳长茂 《Journal of Southwest Jiaotong University(English Edition)》 2005年第2期167-176,共10页
The notion of the inner product of vectors is extended to tensors of different orders, which may replace the vector product usually. The essences of the differential and the codiffcrential forms are pointed out: they... The notion of the inner product of vectors is extended to tensors of different orders, which may replace the vector product usually. The essences of the differential and the codiffcrential forms are pointed out: they represent the tangent surface and the normal surface fluxes of a tensor, reslpetivcly. The definitions of the divergence and the curl of a 2D surface flux of a tensor arc obtained. Maxwell's equations, namely, the constraction law of field, which were usually established based on two conservation laws of electric charge and imaginary magnetic charge, are derived by the author only by using one conservation law ( mass or fluid flux quantity and so on) and the feature of central field (or its composition). By the feature of central field (or its composition), the curl of 2D flux is zero. Both universality of gauge field and the difficulty of magnetic monopole theory ( a magnetic monopole has no effect on electric current just like a couple hasing no effect on the sum of forces) axe presented: magnetic monopole has no the feature of magnet. Finally it is pointed out that the base of relation of mass and energy is already involved in Maxwell's equations. 展开更多
关键词 Maxwell's equations Cud of the surface flux Divergence of the surface flux Gauge field Magnetic monopole
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Limit Treatment of Space-Time Foam Calculations If Non Pathological Big Bang Singularity Is Accessible to Modified Einstein Equations
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作者 Andrew Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 2017年第3期438-453,共16页
When initial radius if Stoica actually derived Einstein equations in a formalism which removes the big bang singularity pathology, then the reason for Planck length no longer holds. We follow what Ng derived as limit ... When initial radius if Stoica actually derived Einstein equations in a formalism which removes the big bang singularity pathology, then the reason for Planck length no longer holds. We follow what Ng derived as limit calculations as to a space time length factor Without the drop off of the vacuum energy as given by is at least the value of . We review the work by Ng as to quantum foam as to how that affects a general expression as to energy when , with determined at least approximately by arguments he presented in 2008 in the Dark side of the universe conference. Well before certain effects make themselves apparent, in ways which are illustrated in the manuscript. Having at a point singularity would remove expansion by the scale factor, so that the extreme version of Stoica’s treatment in an isolated 4-dimensional universe would be no expansion at all. 展开更多
关键词 Fjortoft THEOREM Thermodynamic Potential Matter Creation Vacuum Energy Mach’s THEOREM Non-Pathological sINGULARITY Affecting einstein equations PLANCK Length. BRANE WORLDs
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Friedmann-Like Cosmological Equations for the Accelerated Expansion of the Universe
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作者 G. Alagar Ramanujam 《Journal of Modern Physics》 2020年第7期996-1004,共9页
In recent papers [1] [2] [3], we framed suitable axioms for Space called Super Space by Wheeler [4]. Using our axioms in Newtonian formalism and considering the density of the universe to be constant in time, we showe... In recent papers [1] [2] [3], we framed suitable axioms for Space called Super Space by Wheeler [4]. Using our axioms in Newtonian formalism and considering the density of the universe to be constant in time, we showed in the above references that at t = 0 the radius of the universe need not be zero. And thus, we avoided the problem of singularity. We further showed that the Hubble factor is no longer constant in time and goes on decreasing as confirmed by experiments. We pointed out in the above references that Space is the source of dark energy which is responsible for the accelerated expansion of the universe. With a view to improving the above-mentioned results quantitatively, in this paper, we are discussing the consequences of our axioms using Einstein’s field equations of general theory of relativity. Friedmann-like Cosmological equations with Dark Energy built-in are derived. This derivation is obtained using Robertson-Walker line element and by introducing a suitable expression for Energy-Momentum tensor in terms of matter and Dark energy contents of the universe. The solutions of our cosmological equations obtained here, show that the radius of the universe cannot reach zero but has a minimum value and there is also maximum value for the radius of the universe. The inflationary expansion of the very early universe emerges from our theory. 展开更多
关键词 Axioms for space Dark Energy seed of the Universe einstein’s field equations space (Vacuum) Energy Accelerated Expansion
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Analysis of Maxwell’s Equations. Cosmic Magnetism 被引量:3
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作者 Vladimir S. Netchitailo 《Journal of High Energy Physics, Gravitation and Cosmology》 2018年第1期1-7,共7页
According to Hypersphere World-Universe Model, dark matter particles DIRACs are magnetic dipoles consisting of two Dirac’s monopoles. We conclude that DIRACs are the subject of Maxwell’s equations. So-called “auxil... According to Hypersphere World-Universe Model, dark matter particles DIRACs are magnetic dipoles consisting of two Dirac’s monopoles. We conclude that DIRACs are the subject of Maxwell’s equations. So-called “auxiliary” magnetic field intensity H is indeed current density of magnetic dipoles. The developed approach to magnetic field can explain a wealth of discovered phenomena in Cosmic Magnetism: a dark magnetic field, the large-scale structure of the Milky Way’s magnetic field, and other magnetic phenomena which are only partly related to objects visible in other spectral ranges. 展开更多
关键词 HYPERsPHERE World-Universe Model Maxwell’s equations Dirac’s Monopole MAGNETIC Dipole MAGNETIC field Intensity MAGNETIC DIPOLEs Current Density COsMIC MAGNETIsM Dark MAGNETIC field
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Second Approximation of the Generalized Planetary Equation Based upon Golden Metric Tensors
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作者 Nura Yakubu Hayatu Abbba Ibrahim +1 位作者 Musa Hashimu Umar Bappah Alkali 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第1期7-26,共20页
In this paper, we consider the Post Einstein Planetary equation of motion. We succeeded in offering a solution using second approximation method, in which we obtained eight exact mathematical solutions that rebel amaz... In this paper, we consider the Post Einstein Planetary equation of motion. We succeeded in offering a solution using second approximation method, in which we obtained eight exact mathematical solutions that rebel amazing theoretical results. To the order of C<sup>-2</sup>, two of these exact solutions are reduced to the approximate solutions from the method of successive approximations. 展开更多
关键词 Golden Matric Tensors einstein’s Planetary equation
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Analysis and Simulation of the Influence of Electromagnetic Fields on Living Beings near HV Power Lines Using the FDTD Method
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作者 Anthony Bassesuka Sandoka Nzao 《Open Journal of Applied Sciences》 2023年第12期2343-2359,共17页
Recent decades have seen rapid advances in the field of electrical engineering, such that our environment has become a sea of electrical and magnetic signals, raising questions about the possible effects of low-freque... Recent decades have seen rapid advances in the field of electrical engineering, such that our environment has become a sea of electrical and magnetic signals, raising questions about the possible effects of low-frequency electromagnetic fields on the environment and which are capable of modifying and destroying our ecosystem. Particular interest was given in this article due to a massive influx of population living near high voltage lines. The analysis and simulation of the influence of low frequency electromagnetic fields on living beings in the vicinity of high voltage sources 132 kV and 220 kV in urban areas in DR Congo is the subject of our research with a view to estimating the level of exposure of humans to low frequency electromagnetic fields. To carry out our research, we used the classic method of analyzing the field produced near a high voltage line based on Maxwell’s image theory, the Maxwell-Gauss theorem and Maxwell-Ampère theorem to model and quantify low-frequency electromagnetic fields in the vicinity of high-voltage lines. The 2D FDTD numerical formulation was developed from telegraphers’ equations and allowed us to obtain models of current and voltage induced by electromagnetic fields on living beings below and near HV lines. The different simulations carried out on the proposed models illustrate the effects of the electrical and geometric parameters of the pylons on the distribution of the electromagnetic field in the vicinity of the HV lines. The results obtained were compared to the safety limits recommended by the standards. 展开更多
关键词 Low Frequency Electromagnetic field Modeling field and Health Maxwell’s equations FDTD Method Electromagnetic Compatibility High Voltage Line
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ON THE SINGULARITIES OF SOLUTIONS TO 4-D SEMILINEAR DISPERSIVE WAVE EQUATIONS
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作者 Ning Xu Huicheng Yin 《Analysis in Theory and Applications》 2005年第2期176-187,共12页
In this note, we are concerned with the global singularity structures of weak solutions to 4 - D semilinear dispersive wave equations whose initial data are chosen to be singular at a single point, Combining Strichart... In this note, we are concerned with the global singularity structures of weak solutions to 4 - D semilinear dispersive wave equations whose initial data are chosen to be singular at a single point, Combining Strichartz's inequality with the commutator argument techniques, we show that the weak solutions stay globally conormal if the Cauchy data are conormal 展开更多
关键词 Dispersive wave equation tangent vector fields strichartz's inequality pseudodifferential operator
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Reciprocity Relation between Alternative Gravity Formulas
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作者 Hans Hermann Otto 《Journal of Applied Mathematics and Physics》 2024年第4期1432-1440,共9页
We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists betw... We compare Newton’s force law of universal gravitation with a corrected simple approach based on Bhandari’s recently presented work, where the gravitation constant G is maintained. A reciprocity relation exists between both alternative gravity formulas with respect to the distances between mass centers. We conclude a one-to-one mapping of the two gravitational formulas. We don’t need Einstein’s construct of spacetime bending by matter. 展开更多
关键词 Gravity Formulas Reciprocity Distance Relation NEWTON einstein Bhandari Higgs field Dirac’s Large Number
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A Dynamical Approach to the Explanation of the Upper Critical Field Data of Compressed H3S
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作者 Gulshan Malik Vijaya S. Varma 《World Journal of Condensed Matter Physics》 2023年第3期79-89,共11页
Excellent fits were obtained by Talantsev (MPLB 33, 1950195, 2019) to the temperature (T)-dependent upper critical field (H<sub>c</sub><sub>2</sub>(T)) data of H<sub>3</sub>S report... Excellent fits were obtained by Talantsev (MPLB 33, 1950195, 2019) to the temperature (T)-dependent upper critical field (H<sub>c</sub><sub>2</sub>(T)) data of H<sub>3</sub>S reported by Mozaffari et al. [Nature Communications 10, 2522 (2019)] by employing four alternative phenomenological models, each of which invoked two or more properties from its sample-specific set S<sub>1</sub> = {T<sub>c</sub>, gap, coherence length, penetration depth, jump in sp.ht.} and a single value of the effective mass (m*) of an electron. Based on the premise that the variation of H<sub>c</sub><sub>2</sub>(T) is due to the variation of the chemical potential μ(T), we report here fits to the same data by employing a T-, μ- and m*-dependent equation for H<sub>c</sub><sub>2</sub>(T) and three models of μ(T), viz. the linear, the parabolic and the concave-upward model. For temperatures up to which the data are available, each of these provides a good fit. However, for lower values of T, their predictions differ. Notably, the predicted values of H<sub>c</sub><sub>2</sub>(0) are much higher than in any of the models dealt with by Talantsev. In sum, we show here that the addressed data are explicable in a framework comprising the set S<sub>2</sub> = {μ, m*, interaction parameter λ<sub>m</sub>, Landau index N<sub>L</sub>}, which is altogether different from S<sub>1</sub>. 展开更多
关键词 Compressed H<sub>2sub>s Upper Critical Magnetic field Pairing equation Incorporating Temperature Chemical Potential and Magnetic field Temperature Dependence of the Chemical Potential
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高维静态流体球的Einstein场方程新解(英文)
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作者 谭振强 罗量锱 +1 位作者 黄湘寒 沈有根 《广西大学学报(自然科学版)》 CAS CSCD 2008年第1期87-90,共4页
本文求解了高维静态流体球的Einstein引力场方程,得到了两个新的解析解.
关键词 einstein场方程 D维时空 静态理想流体球 新解析解
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Einstein转盘引力场精确解
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作者 唐智明 樊军辉 《长沙铁道学院学报》 CSCD 1990年第2期6-9,共4页
本文解爱因斯坦场方程得出了转盘的度规。
关键词 爱因斯坦 场方程 转盘 严格解
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宇宙的演化、星体的内能和Einstein场方程
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作者 邓昭镜 陈华林 《西南师范大学学报(自然科学版)》 CAS CSCD 北大核心 2013年第7期37-40,共4页
首先根据Einstein场方程中时时分量方程的非独立性,分析了当今天体物理主流学派所提出的"宇亩始终在加速地膨胀"这一论断的错误之所在;进一步又根据系统的内能对时空曲率k的正比关系,分析了天体的内能和压強都是可正可负的,... 首先根据Einstein场方程中时时分量方程的非独立性,分析了当今天体物理主流学派所提出的"宇亩始终在加速地膨胀"这一论断的错误之所在;进一步又根据系统的内能对时空曲率k的正比关系,分析了天体的内能和压強都是可正可负的,而且正压系統才会自膨胀,负压系统必然自收缩;最后,直接根据Einstein场方程和物态方程分析了天体系统自膨胀和自收缩的无限循环. 展开更多
关键词 einstein场方程 星系的内能 时空曲率 标度因子
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基于S-A模型的覆冰输电线绕流数值分析 被引量:1
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作者 廖绍凯 张研 陈达 《河海大学学报(自然科学版)》 CAS CSCD 北大核心 2023年第1期110-117,共8页
基于Spalart-Allmaras湍流模型(S-A模型)封闭的雷诺平均N-S方程,采用沿均匀流线的三阶Runge-Kutta法和Galerkin法分别进行时间和空间离散,得到了湍流方程的有限元格式。采用自编Matlab程序,数值模拟了不同风攻角下覆冰输电线绕流问题,... 基于Spalart-Allmaras湍流模型(S-A模型)封闭的雷诺平均N-S方程,采用沿均匀流线的三阶Runge-Kutta法和Galerkin法分别进行时间和空间离散,得到了湍流方程的有限元格式。采用自编Matlab程序,数值模拟了不同风攻角下覆冰输电线绕流问题,得到了覆冰输电线绕流瞬态和时均流场、气动力系数时程曲线和平均气动力系数随风攻角的变化关系,并与试验结果进行对比,验证了该算法的有效性。基于流场演化和平均压力分布,分析表明风攻角变化引起的边界层分离点转移是产生升力系数尖峰突跳现象的主要原因。 展开更多
关键词 spalart-Allmaras模型 雷诺平均N-s方程 RUNGE-KUTTA法 有限元格式 覆冰输电线 流场演化 气动力系数
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微扰法解Einstein场方程
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作者 李新克 全条芬 +2 位作者 杨淑敏 姚乾凯 马光文 《郑州大学学报(理学版)》 CAS 2007年第4期156-159,共4页
首先从已知具有对角型度规的Einstein场方程的精确解出发,近似推导了含有微扰条件下的场方程形式;其次,利用这一微扰形式具体计算了静态球对称引力场的外部微扰解,并进而讨论了球状星系外部的引力特征.结果表明,该微扰解不仅可以与内部... 首先从已知具有对角型度规的Einstein场方程的精确解出发,近似推导了含有微扰条件下的场方程形式;其次,利用这一微扰形式具体计算了静态球对称引力场的外部微扰解,并进而讨论了球状星系外部的引力特征.结果表明,该微扰解不仅可以与内部解衔接,而且在消除微扰的情况下还可以自动恢复到Schwarzchild解的形式. 展开更多
关键词 einstein场方程 schwarzchild解 微扰
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