A semiclassical particle moving near the horizon of a Schwarzschild black hole is chaotic,and its Lyapunov exponent saturates the chaos bound proposed by Maldacena,Shenker,and Stanford,with the temperature being the H...A semiclassical particle moving near the horizon of a Schwarzschild black hole is chaotic,and its Lyapunov exponent saturates the chaos bound proposed by Maldacena,Shenker,and Stanford,with the temperature being the Hawking temperature.Motivated by this,we consider the Lyapunov exponents of scalar and spinor fields in Schwarzschild spacetime by calculating their out-of-time-ordered commutators along the radial direction.Numerically,we find that the Lyapunov exponent of the scalar field is smaller than that of the spinor field.They are mainly contributed by the bound states near the horizon and lie below the chaos bound.展开更多
What is spacetime?How do we perceive this medium?How can we fit it into our everyday linear lives?How can we situate ourselves within it in our post-industrial worldview,in an unsustainable world?This philosophical es...What is spacetime?How do we perceive this medium?How can we fit it into our everyday linear lives?How can we situate ourselves within it in our post-industrial worldview,in an unsustainable world?This philosophical essay adopts a phenomenological method to interrogate the meaning of this fundamental dimension of reality.Spacetime is interpreted not merely as a physical structure but as a plastic field whose instability shapes inner and social life.Yet the contemporary human condition is marked by a profound alienation,much of which derives from a self-inflicted existential disorientation:I once chose exile and moved to a remote island in the Atlantic Ocean,becoming my own research material.In search of genuine contact with nature,the nonverbal appeared as a necessity.I turned to music as an archetypal language,in the Romantic sense of a medium offering pre-conceptual access to the real.I composed Light Atlas,a six-movement work aiming to capture the flight of seagulls and the eternal struggle between light and darkness.This led me back to physics,to my original question:the lived perception of spacetime.展开更多
In a fractal zeta universe of bifurcated, ripped spacetime, the Millikan experiment, the quantum Hall effect, atmospheric clouds and universe clouds are shown to be self-similar with mass ratio of about 1020. Chaotic ...In a fractal zeta universe of bifurcated, ripped spacetime, the Millikan experiment, the quantum Hall effect, atmospheric clouds and universe clouds are shown to be self-similar with mass ratio of about 1020. Chaotic one-dimensional period-doublings as iterated hyperelliptic-elliptic curves are used to explain n-dim Kepler- and Coulomb singularities. The cosmic microwave background and cosmic rays are explained as bifurcated, ripped spacetime tensile forces. First iterated binary tree cloud cycles are related to emissions 1…1000 GHz. An interaction-independent universal vacuum density allows to predict large area correlated cosmic rays in quantum Hall experiments which would generate local nuclear disintegration stars, enhanced damage of layers and enhanced air ionization. A self-similarity between conductivity plateau and atmospheric clouds is extended to correlations in atmospheric layer, global temperature and climate.展开更多
Based on the Many Worlds Interpretation,I describe reality as a multilayer spacetime,where parallel layers play the role of alternative timelines.I link physics to ethics,arguing that one’s moral choices shape one’s...Based on the Many Worlds Interpretation,I describe reality as a multilayer spacetime,where parallel layers play the role of alternative timelines.I link physics to ethics,arguing that one’s moral choices shape one’s course in the multiverse.I consider one’s ethical decisions as decoherence events,leading to movement between alternative timelines,lighter(higher)or heavier(lower)realities.Sometimes in one’s curvilinear path in spacetime,one can even experience falling toward lower layers,slipping through wormholes.This theory supports free will and the simulation hypothesis.With this background,I explore the idea that a new theory of gravity might open new possibilities to shape matter and change our worldview through the invention of new technology,transforming information into waves and then into solid matter,paving the way for a new Multiverse Aeon for humanity.展开更多
Gravitational collapse and bubble evolution in the asymptotic Friedmann–Lemaître–Robertson–Walker(FLRW)Universe is an intriguing and intricate problem.We systematically analyze the dynamics of contact Schwarzs...Gravitational collapse and bubble evolution in the asymptotic Friedmann–Lemaître–Robertson–Walker(FLRW)Universe is an intriguing and intricate problem.We systematically analyze the dynamics of contact Schwarzschild–FLRW(McVittie)spacetimes,focusing on their general junction conditions and introducing a novel function to simplify the extrinsic curvature and surface stress–energy tensor.Both static and dynamic scenarios are explored,including special cases such as Schwarzschild,FLRW,and Einstein–Straus configurations using our general framework.Numerical calculations further investigate the evolution of concentric McVittie spacetimes under various initial conditions,incorporatingΛ-CDM cosmological models to better reflect realistic cosmic backgrounds.These results offer deep insights into the interplay between the McVittie mass parameter,initial peculiar velocity,and the influence of dark energy,providing a unified perspective for understanding gravitational collapse and bubble evolution in cosmology and astrophysics.展开更多
In this work we study gravitational lensing of the wormhole in the Eddington-inspired Born–Infeld(EiBI)spacetime that incorporates with a cosmic string.It is found that the presence of a cosmic string can enhance the...In this work we study gravitational lensing of the wormhole in the Eddington-inspired Born–Infeld(EiBI)spacetime that incorporates with a cosmic string.It is found that the presence of a cosmic string can enhance the light deflection in the strong-field limit,compared to the Ellis–Bronnikov wormhole.The magnification effects of this composite structure could cause some substantial impacts on the angle separation between the first and the rest of the images,and their relative brightness.Furthermore,based on these observables,we model some observable aspects in the strong-and the weak-field limits.The presence of a cosmic string can affect some distinguishable observables compared to the wormhole without cosmic string.This work could deepen our understanding of the spacetime structure of the wormhole in EiBI spacetime with one-dimensional topological defects.展开更多
In this paper,we present the second post-Newtonian solution for the quasi-Keplerian motion of a test particle in the regular Simpson–Visser black-bounce spacetime which has a bounce parameter a.The obtained solution ...In this paper,we present the second post-Newtonian solution for the quasi-Keplerian motion of a test particle in the regular Simpson–Visser black-bounce spacetime which has a bounce parameter a.The obtained solution is formulated in terms of orbital energy,angular momentum,and the bounce parameter of the black hole.We explicitly analyze the leading effects of the bounce parameter which has dimensions of length,on the test particle’s orbit,including the periastron advance and orbital period.Then,we apply this model to the precessing motion of OJ 287 and determine the upper limits of the dimensionless bounce parameter as a/m=3.45±0.01,where m is the mass of the regular black hole.Compared with the bound given by the periastron advance of star S2,our bound on a/m is reduced by one order of magnitude,although our upper limit of a still needs further improvement.展开更多
This research paper seeks to investigate the characteristics of almost Riemann solitons and almost gradient Riemann solitons within the framework of generalized Robertson–Walker(GRW)spacetimes that incorporate imperf...This research paper seeks to investigate the characteristics of almost Riemann solitons and almost gradient Riemann solitons within the framework of generalized Robertson–Walker(GRW)spacetimes that incorporate imperfect fluids.Our study begins by defining specific properties of the potential vector field linked to these solitons.We examine the potential vector field of an almost Riemann soliton on GRW imperfect fluid spacetimes,establishing that it aligns collinearly with a unit timelike torse-forming vector field.This leads us to express the scalar curvature in relation to the structures of soliton and spacetime.Furthermore,we explore the characteristics of an almost gradient Riemann soliton with a potential functionψacross a range of GRW imperfect fluid spacetimes,deriving a formula for the Laplacian ofψ.We also categorize almost Riemann solitons on GRW imperfect fluid spacetimes into three types:shrinking,steady,and expanding,when the potential vector field of the soliton is Killing.We prove that a GRW imperfect fluid spacetime with constant scalar curvature and a Killing vector field admits an almost Riemann soliton.Additionally,we demonstrate that if the potential vector field of the almost Riemann soliton is aν(Ric)-vector,or if the GRW imperfect fluid spacetime is W_2-flat or pseudo-projectively flat,the resulting spacetime is classified as a dark fluid.展开更多
目的:分析2015—2024年安阳市殷都区疑似预防接种异常反应(adverse event following immunization,AEFI)监测数据,为优化基层AEFI监测系统提供实证依据。方法:AEFI个案信息和接种剂次数据分别来源于我国AEFI监测信息管理系统及河南省免...目的:分析2015—2024年安阳市殷都区疑似预防接种异常反应(adverse event following immunization,AEFI)监测数据,为优化基层AEFI监测系统提供实证依据。方法:AEFI个案信息和接种剂次数据分别来源于我国AEFI监测信息管理系统及河南省免疫规划信息管理系统。采用SPSS 22.0软件对数据进行统计分析,采用SatScanv 10.0软件进行时空扫描分析。结果:2015—2024年安阳市殷都区累计报告AEFI 3311例,年均报告发生率为99.49/10万,总体报告发生率呈上升趋势(χ^(2)=42.43,P<0.05)。AEFI报告集中在5—9月,发现2个时空聚集区。男女性别比为1.05∶1,以<1岁和1~4岁儿童为主。AEFI报告发生率一般反应为98.10/10万,异常反应为0.93/10万,偶合症为0.45/10万。从AEFI接种到发生、发生到就诊的时间间隔主要集中在48小时内。结论:2015—2024年安阳市殷都区AEFI监测系统常规运行平稳,但存在应急韧性不足、数据质量有待提升、监测网络不均衡的问题。建议通过构建应急机制、强化数据管理与精准督导,系统提升监测效能。展开更多
The present paper is basically a synthesis resulting from incorporating Kerr spinning black hole geometry into E-infinity topology, then letting the result bares on the vacuum zero point Casimir effect as well as the ...The present paper is basically a synthesis resulting from incorporating Kerr spinning black hole geometry into E-infinity topology, then letting the result bares on the vacuum zero point Casimir effect as well as the cosmic dark energy and dark matter density. In E-infinity theory a quantum particle is represented by a Hausdorff dimension Φ where Φ =2/(√5+1) . The quantum wave on the other hand is represented by Φ2 . To be wave and a particle simultaneously intersection theory leads us to?(Φ) (Φ)2= Φ3 which will be shown here to be twice the value of the famous Casimir force of the vacuum for a massless scalar field. Thus in the present work a basically topological interpretation of the Casimir effect is given as a natural intrinsic property of the geometrical topological structure of the quantum-Cantorian micro spacetime. This new interpretation compliments the earlier conventional interpretation as vacuum fluctuation or as a Schwinger source and links the Casimir energy to the so called missing dark energy density of the cosmos. From the view point of the present work Casimir pressure is a local effect acting on the Casimir plates constituting the local boundary condition while dark energy is nothing but the global combined effect of infinitely many quantum waves acting on the Möbius-like boundary of the holographic boundary of the entire universe. Since this higher dimensional Möbius-like boundary is one sided, there is no outside to balance the internal collective Casimir pressure which then manifests itself as the force behind cosmic expansion, that is to say, dark energy. Thus analogous to the exact irrational value of ordinary energy density of spacetime E(O)=(Φ5/2) mc2 we now have P (Casimir) = (Φ3/2)(ch/d2) where c is the speed of light, m is the mass, h is the Planck constant and d is the plate separation. In addition the new emerging geometry combined with the topology of E-infinity theory leads directly to identifying dark matter with the quasi matter of the ergosphere. As a direct consequence of this new insight E=mc2 which can be written as E = E (O) + E (D)?where the exact rational approximation is E (O)=mc2/22 is?the ordinary energy density of the cosmos and the exact rational approximation E (D)=mc2/(21/22) is the corresponding dark energy which could be subdivided once more albeit truly approximately into E(D)=mc2/(5/22)?+mc2/(16/22)??where 5 is the Kaluza Klein spacetime dimension, 16 are the bosonic extra dimensions of Heterotic superstrings and 5/22 □?22% is approximately the density of the dark matter-like energy of the ergosphere of the Kerr geometry. As for the actual design of our nano reactor, this is closely related to branching clusters of polymer, frequently called lattice animals. In other words we will have Casimir spheres instead of Casimir plates and these spheres will be basically nano particles modelling lattice animals. Here D=?4 will be regarded as spacetime dimensionality while D=6 of percolations are the compactified super string dimensions and D=8 is the dimension of a corresponding super space.展开更多
We use a dual Einstein-Kaluza spacetime to calculate the exact energy density of dark energy and dark matter using a novel topological computation method. Starting from the said spacetime and ‘tHooft’s topological r...We use a dual Einstein-Kaluza spacetime to calculate the exact energy density of dark energy and dark matter using a novel topological computation method. Starting from the said spacetime and ‘tHooft’s topological renormalon as well as the corresponding symmetry group, we show how the zero set quantum particle and the empty set quantum wave interact with the vacuum and give rise to pure dark energy and pure dark matter all along with ordinary energy density of the cosmos. The consistency of the exact calculation and the accurate observations attests to the reality of ‘tHooft’s renormalon dark matter, pure dark energy and accelerated cosmic expansion.展开更多
We provide a new class of interior solution of a(2+1)-dimensional anisotropic star in Finch and Skea spacetime corresponding to the BTZ black hole. We develop the model by considering the MIT bag model EOS and a parti...We provide a new class of interior solution of a(2+1)-dimensional anisotropic star in Finch and Skea spacetime corresponding to the BTZ black hole. We develop the model by considering the MIT bag model EOS and a particular ansatz for the metric function grrproposed by Finch and Skea [M.R. Finch and J.E.F. Skea, Class. Quantum.Grav. 6(1989) 467]. Our model is free from central singularity and satisfies all the physical requirements for the acceptability of the model.展开更多
The paper presents a very simple and straight forward yet pure mathematical derivation of the structure of actual spacetime from quantum set theory. This is achieved by utilizing elements of the topological theory of ...The paper presents a very simple and straight forward yet pure mathematical derivation of the structure of actual spacetime from quantum set theory. This is achieved by utilizing elements of the topological theory of cobordism and the Menger-Urysohn dimensional theory in conjunction with von Neumann-Connes dimensional function of Klein-Penrose modular holographic boundary of the E8E8 exceptional Lie group bulk of our universe. The final result is a lucid sharp mental picture, namely that the quantum wave is an empty set representing the surface, i.e. boundary of the zero set quantum particle and in turn quantum spacetime is simply the boundary or the surface of the quantum wave empty set. The essential difference of the quantum wave and quantum spacetime is that the wave is a simple empty set while spacetime is a multi-fractal type of infinitely many empty sets with increasing degrees of emptiness.展开更多
In this article,a meshless method using the spacetime collocation for solving the two-dimensional backward heat conduction problem(BHCP)is proposed.The spacetime collocation meshless method(SCMM)is to derive the gener...In this article,a meshless method using the spacetime collocation for solving the two-dimensional backward heat conduction problem(BHCP)is proposed.The spacetime collocation meshless method(SCMM)is to derive the general solutions as the basis functions for the two-dimensional transient heat equation using the separation of variables.Numerical solutions of the heat conduction problem are expressed as a series using the addition theorem.Because the basis functions are the general solutions of the governing equation,the boundary points may be collocated on the spacetime boundary of the domain.The proposed method is verified by conducting several heat conduction problems.We also carry out numerical applications to compare the SCMM with other meshless methods.The results show that the SCMM is accurate and efficient.Furthermore,it is found that the recovered boundary data on inaccessible boundary can be obtained with high accuracy even though the over specified data are provided only at a 1/6 portion of the spacetime boundary.展开更多
By bifurcation and topological methods,we study the global structure of a radial nodal solutions set of the mean curvature equation in a standard static spacetime div {a∇u√1−a^(2)|∇u|^(2)+g(∇u,∇a)/√1−a^(2)|∇u|^(2)=...By bifurcation and topological methods,we study the global structure of a radial nodal solutions set of the mean curvature equation in a standard static spacetime div {a∇u√1−a^(2)|∇u|^(2)+g(∇u,∇a)/√1−a^(2)|∇u|^(2)=λNH,with a 0-Dirichlet boundary condition on the unit ball.According to the behavior of H near 0,we obtain the global structure of sign-changing radial spacelike graphs for this problem.展开更多
Some properties related to the NUT-Taub-like spacetime, such as the surface of infinite red-shift, horizon, singularity and the area of the NUT-Taub-like black hole are discussed. Furthermore, the geodesics in the NUT...Some properties related to the NUT-Taub-like spacetime, such as the surface of infinite red-shift, horizon, singularity and the area of the NUT-Taub-like black hole are discussed. Furthermore, the geodesics in the NUT-Taub-like spacetime are obtained in some special cases. Specifically, the circular orbits for a massive particle are derived, which can reduce to the cases of the Schwarzschild spacetime and the NUT-Taub spacetime when m^＊ = 0 and m^＊ 〈〈 M, respectively.展开更多
Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-- Hawking black hole entropy. In particular, many researchers have expressed a vested interest in the coetticient ...Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-- Hawking black hole entropy. In particular, many researchers have expressed a vested interest in the coetticient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the correction value of the black hole entropy by utilizing the generalized uncertainty prlnciple and obtain the correction term caused by the generalized uncertainty principle. Because in our calculation we think that the Bekenstein-Hawking area theorem is still valid after considering the generalized uncertainty principle, we derive that the coefficient of the logarithmic term of the black hole entropy correction term is positive. This result is different from the known result at present. Our method is valid not only for four-dimensional spacetimes but also for higher-dimensional spacetimes. In the whole process, the physics idea is clear and calculation is simple. It offers a new way for studying the entropy correction of the complicated spacetime.展开更多
We introduce an ultra high energy combined KAM-Rindler fractal spacetime quantum manifold, which increasingly resembles Einstein’s smooth relativity spacetime, with decreasing energy. That way we derive an effective ...We introduce an ultra high energy combined KAM-Rindler fractal spacetime quantum manifold, which increasingly resembles Einstein’s smooth relativity spacetime, with decreasing energy. That way we derive an effective quantum gravity energy-mass relation and compute a dark energy density in complete agreement with all cosmological measurements, specifically WMAP and type 1a supernova. In particular we find that ordinary measurable energy density is given by E1= mc2 /22 while the dark energy density of the vacuum is given by E2 = mc2 (21/22). The sum of both energies is equal to Einstein’s energy E = mc2. We conclude that E= mc2 makes no distinction between ordinary energy and dark energy. More generally we conclude that the geometry and topology of quantum entanglement create our classical spacetime and glue it together and conversely quantum entanglement is the logical consequence of KAM theorem and zero measure topology of quantum spacetime. Furthermore we show via our version of a Rindler hyperbolic spacetime that Hawking negative vacuum energy, Unruh temperature and dark energy are different sides of the same medal.展开更多
Looped light in a recent sophisticated real three-slit experiment is interpreted as a strong justification of the old theoretical Peano-Hilbert spacetime model of Ord and El Naschie. This in turn entails the existence...Looped light in a recent sophisticated real three-slit experiment is interpreted as a strong justification of the old theoretical Peano-Hilbert spacetime model of Ord and El Naschie. This in turn entails the existence of extra fractal dimensions and consequently of real dark energy density in full agreement with previous analysis as well as accurate measurements and observations of COBE, WMAP, and the type 1a supernova.展开更多
基金supported by the National Natural Science Foundation of China with Grants No.12174067 and No.11804223。
文摘A semiclassical particle moving near the horizon of a Schwarzschild black hole is chaotic,and its Lyapunov exponent saturates the chaos bound proposed by Maldacena,Shenker,and Stanford,with the temperature being the Hawking temperature.Motivated by this,we consider the Lyapunov exponents of scalar and spinor fields in Schwarzschild spacetime by calculating their out-of-time-ordered commutators along the radial direction.Numerically,we find that the Lyapunov exponent of the scalar field is smaller than that of the spinor field.They are mainly contributed by the bound states near the horizon and lie below the chaos bound.
文摘What is spacetime?How do we perceive this medium?How can we fit it into our everyday linear lives?How can we situate ourselves within it in our post-industrial worldview,in an unsustainable world?This philosophical essay adopts a phenomenological method to interrogate the meaning of this fundamental dimension of reality.Spacetime is interpreted not merely as a physical structure but as a plastic field whose instability shapes inner and social life.Yet the contemporary human condition is marked by a profound alienation,much of which derives from a self-inflicted existential disorientation:I once chose exile and moved to a remote island in the Atlantic Ocean,becoming my own research material.In search of genuine contact with nature,the nonverbal appeared as a necessity.I turned to music as an archetypal language,in the Romantic sense of a medium offering pre-conceptual access to the real.I composed Light Atlas,a six-movement work aiming to capture the flight of seagulls and the eternal struggle between light and darkness.This led me back to physics,to my original question:the lived perception of spacetime.
文摘In a fractal zeta universe of bifurcated, ripped spacetime, the Millikan experiment, the quantum Hall effect, atmospheric clouds and universe clouds are shown to be self-similar with mass ratio of about 1020. Chaotic one-dimensional period-doublings as iterated hyperelliptic-elliptic curves are used to explain n-dim Kepler- and Coulomb singularities. The cosmic microwave background and cosmic rays are explained as bifurcated, ripped spacetime tensile forces. First iterated binary tree cloud cycles are related to emissions 1…1000 GHz. An interaction-independent universal vacuum density allows to predict large area correlated cosmic rays in quantum Hall experiments which would generate local nuclear disintegration stars, enhanced damage of layers and enhanced air ionization. A self-similarity between conductivity plateau and atmospheric clouds is extended to correlations in atmospheric layer, global temperature and climate.
文摘Based on the Many Worlds Interpretation,I describe reality as a multilayer spacetime,where parallel layers play the role of alternative timelines.I link physics to ethics,arguing that one’s moral choices shape one’s course in the multiverse.I consider one’s ethical decisions as decoherence events,leading to movement between alternative timelines,lighter(higher)or heavier(lower)realities.Sometimes in one’s curvilinear path in spacetime,one can even experience falling toward lower layers,slipping through wormholes.This theory supports free will and the simulation hypothesis.With this background,I explore the idea that a new theory of gravity might open new possibilities to shape matter and change our worldview through the invention of new technology,transforming information into waves and then into solid matter,paving the way for a new Multiverse Aeon for humanity.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.12275106 and12235019。
文摘Gravitational collapse and bubble evolution in the asymptotic Friedmann–Lemaître–Robertson–Walker(FLRW)Universe is an intriguing and intricate problem.We systematically analyze the dynamics of contact Schwarzschild–FLRW(McVittie)spacetimes,focusing on their general junction conditions and introducing a novel function to simplify the extrinsic curvature and surface stress–energy tensor.Both static and dynamic scenarios are explored,including special cases such as Schwarzschild,FLRW,and Einstein–Straus configurations using our general framework.Numerical calculations further investigate the evolution of concentric McVittie spacetimes under various initial conditions,incorporatingΛ-CDM cosmological models to better reflect realistic cosmic backgrounds.These results offer deep insights into the interplay between the McVittie mass parameter,initial peculiar velocity,and the influence of dark energy,providing a unified perspective for understanding gravitational collapse and bubble evolution in cosmology and astrophysics.
基金supported by the Youth Program of the Natural Science Foundation of Guangxi(Grant No.2021GXNSFBA075049)the Doctor Start-up Foundation of Guangxi University of Science and Technology(Grant No.19Z21)+3 种基金supported by the National Natural Science Foundation of China(Grant No.12165009)supported by the National Natural Science Foundation of China(Grant No.11865005)Hunan Natural Provincial Science Foundation(Grant No.2023JJ30487)supported by the starting Foundation of Guangxi University of Science and Technology(Grant No.24Z17)。
文摘In this work we study gravitational lensing of the wormhole in the Eddington-inspired Born–Infeld(EiBI)spacetime that incorporates with a cosmic string.It is found that the presence of a cosmic string can enhance the light deflection in the strong-field limit,compared to the Ellis–Bronnikov wormhole.The magnification effects of this composite structure could cause some substantial impacts on the angle separation between the first and the rest of the images,and their relative brightness.Furthermore,based on these observables,we model some observable aspects in the strong-and the weak-field limits.The presence of a cosmic string can affect some distinguishable observables compared to the wormhole without cosmic string.This work could deepen our understanding of the spacetime structure of the wormhole in EiBI spacetime with one-dimensional topological defects.
基金supported by the National Natural Science Foundation of China(Grant Nos.12303079,12481540180 and 12475057)the support of the postdoctoral program of purple Mountain Observatory,Chinese Academy of Sciences。
文摘In this paper,we present the second post-Newtonian solution for the quasi-Keplerian motion of a test particle in the regular Simpson–Visser black-bounce spacetime which has a bounce parameter a.The obtained solution is formulated in terms of orbital energy,angular momentum,and the bounce parameter of the black hole.We explicitly analyze the leading effects of the bounce parameter which has dimensions of length,on the test particle’s orbit,including the periastron advance and orbital period.Then,we apply this model to the precessing motion of OJ 287 and determine the upper limits of the dimensionless bounce parameter as a/m=3.45±0.01,where m is the mass of the regular black hole.Compared with the bound given by the periastron advance of star S2,our bound on a/m is reduced by one order of magnitude,although our upper limit of a still needs further improvement.
文摘This research paper seeks to investigate the characteristics of almost Riemann solitons and almost gradient Riemann solitons within the framework of generalized Robertson–Walker(GRW)spacetimes that incorporate imperfect fluids.Our study begins by defining specific properties of the potential vector field linked to these solitons.We examine the potential vector field of an almost Riemann soliton on GRW imperfect fluid spacetimes,establishing that it aligns collinearly with a unit timelike torse-forming vector field.This leads us to express the scalar curvature in relation to the structures of soliton and spacetime.Furthermore,we explore the characteristics of an almost gradient Riemann soliton with a potential functionψacross a range of GRW imperfect fluid spacetimes,deriving a formula for the Laplacian ofψ.We also categorize almost Riemann solitons on GRW imperfect fluid spacetimes into three types:shrinking,steady,and expanding,when the potential vector field of the soliton is Killing.We prove that a GRW imperfect fluid spacetime with constant scalar curvature and a Killing vector field admits an almost Riemann soliton.Additionally,we demonstrate that if the potential vector field of the almost Riemann soliton is aν(Ric)-vector,or if the GRW imperfect fluid spacetime is W_2-flat or pseudo-projectively flat,the resulting spacetime is classified as a dark fluid.
文摘The present paper is basically a synthesis resulting from incorporating Kerr spinning black hole geometry into E-infinity topology, then letting the result bares on the vacuum zero point Casimir effect as well as the cosmic dark energy and dark matter density. In E-infinity theory a quantum particle is represented by a Hausdorff dimension Φ where Φ =2/(√5+1) . The quantum wave on the other hand is represented by Φ2 . To be wave and a particle simultaneously intersection theory leads us to?(Φ) (Φ)2= Φ3 which will be shown here to be twice the value of the famous Casimir force of the vacuum for a massless scalar field. Thus in the present work a basically topological interpretation of the Casimir effect is given as a natural intrinsic property of the geometrical topological structure of the quantum-Cantorian micro spacetime. This new interpretation compliments the earlier conventional interpretation as vacuum fluctuation or as a Schwinger source and links the Casimir energy to the so called missing dark energy density of the cosmos. From the view point of the present work Casimir pressure is a local effect acting on the Casimir plates constituting the local boundary condition while dark energy is nothing but the global combined effect of infinitely many quantum waves acting on the Möbius-like boundary of the holographic boundary of the entire universe. Since this higher dimensional Möbius-like boundary is one sided, there is no outside to balance the internal collective Casimir pressure which then manifests itself as the force behind cosmic expansion, that is to say, dark energy. Thus analogous to the exact irrational value of ordinary energy density of spacetime E(O)=(Φ5/2) mc2 we now have P (Casimir) = (Φ3/2)(ch/d2) where c is the speed of light, m is the mass, h is the Planck constant and d is the plate separation. In addition the new emerging geometry combined with the topology of E-infinity theory leads directly to identifying dark matter with the quasi matter of the ergosphere. As a direct consequence of this new insight E=mc2 which can be written as E = E (O) + E (D)?where the exact rational approximation is E (O)=mc2/22 is?the ordinary energy density of the cosmos and the exact rational approximation E (D)=mc2/(21/22) is the corresponding dark energy which could be subdivided once more albeit truly approximately into E(D)=mc2/(5/22)?+mc2/(16/22)??where 5 is the Kaluza Klein spacetime dimension, 16 are the bosonic extra dimensions of Heterotic superstrings and 5/22 □?22% is approximately the density of the dark matter-like energy of the ergosphere of the Kerr geometry. As for the actual design of our nano reactor, this is closely related to branching clusters of polymer, frequently called lattice animals. In other words we will have Casimir spheres instead of Casimir plates and these spheres will be basically nano particles modelling lattice animals. Here D=?4 will be regarded as spacetime dimensionality while D=6 of percolations are the compactified super string dimensions and D=8 is the dimension of a corresponding super space.
文摘We use a dual Einstein-Kaluza spacetime to calculate the exact energy density of dark energy and dark matter using a novel topological computation method. Starting from the said spacetime and ‘tHooft’s topological renormalon as well as the corresponding symmetry group, we show how the zero set quantum particle and the empty set quantum wave interact with the vacuum and give rise to pure dark energy and pure dark matter all along with ordinary energy density of the cosmos. The consistency of the exact calculation and the accurate observations attests to the reality of ‘tHooft’s renormalon dark matter, pure dark energy and accelerated cosmic expansion.
文摘We provide a new class of interior solution of a(2+1)-dimensional anisotropic star in Finch and Skea spacetime corresponding to the BTZ black hole. We develop the model by considering the MIT bag model EOS and a particular ansatz for the metric function grrproposed by Finch and Skea [M.R. Finch and J.E.F. Skea, Class. Quantum.Grav. 6(1989) 467]. Our model is free from central singularity and satisfies all the physical requirements for the acceptability of the model.
文摘The paper presents a very simple and straight forward yet pure mathematical derivation of the structure of actual spacetime from quantum set theory. This is achieved by utilizing elements of the topological theory of cobordism and the Menger-Urysohn dimensional theory in conjunction with von Neumann-Connes dimensional function of Klein-Penrose modular holographic boundary of the E8E8 exceptional Lie group bulk of our universe. The final result is a lucid sharp mental picture, namely that the quantum wave is an empty set representing the surface, i.e. boundary of the zero set quantum particle and in turn quantum spacetime is simply the boundary or the surface of the quantum wave empty set. The essential difference of the quantum wave and quantum spacetime is that the wave is a simple empty set while spacetime is a multi-fractal type of infinitely many empty sets with increasing degrees of emptiness.
文摘In this article,a meshless method using the spacetime collocation for solving the two-dimensional backward heat conduction problem(BHCP)is proposed.The spacetime collocation meshless method(SCMM)is to derive the general solutions as the basis functions for the two-dimensional transient heat equation using the separation of variables.Numerical solutions of the heat conduction problem are expressed as a series using the addition theorem.Because the basis functions are the general solutions of the governing equation,the boundary points may be collocated on the spacetime boundary of the domain.The proposed method is verified by conducting several heat conduction problems.We also carry out numerical applications to compare the SCMM with other meshless methods.The results show that the SCMM is accurate and efficient.Furthermore,it is found that the recovered boundary data on inaccessible boundary can be obtained with high accuracy even though the over specified data are provided only at a 1/6 portion of the spacetime boundary.
基金Research supported by NNSF of China(11871129)Xinghai Youqing funds from Dalian University of Technology+1 种基金NSF of Liaoning Province(2019-MS-109)HSSF of Chinese Ministry of Education(20YJA790049).
文摘By bifurcation and topological methods,we study the global structure of a radial nodal solutions set of the mean curvature equation in a standard static spacetime div {a∇u√1−a^(2)|∇u|^(2)+g(∇u,∇a)/√1−a^(2)|∇u|^(2)=λNH,with a 0-Dirichlet boundary condition on the unit ball.According to the behavior of H near 0,we obtain the global structure of sign-changing radial spacelike graphs for this problem.
基金Project supported by the National Natural Science Foundation of China （Grant No 10475036）, the Natural Science Foundation of Liaoning Province, China （Grant No 20032012） and the Scientific Research Foundation of the Higher Education Institute of Liaoning Province, China （Grant No 05L215）.
文摘Some properties related to the NUT-Taub-like spacetime, such as the surface of infinite red-shift, horizon, singularity and the area of the NUT-Taub-like black hole are discussed. Furthermore, the geodesics in the NUT-Taub-like spacetime are obtained in some special cases. Specifically, the circular orbits for a massive particle are derived, which can reduce to the cases of the Schwarzschild spacetime and the NUT-Taub spacetime when m^＊ = 0 and m^＊ 〈〈 M, respectively.
基金The project supported by the Natural Science Foundation of Shanxi Province under Grant No. 2006011012 tCorresponding author,
文摘Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-- Hawking black hole entropy. In particular, many researchers have expressed a vested interest in the coetticient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the correction value of the black hole entropy by utilizing the generalized uncertainty prlnciple and obtain the correction term caused by the generalized uncertainty principle. Because in our calculation we think that the Bekenstein-Hawking area theorem is still valid after considering the generalized uncertainty principle, we derive that the coefficient of the logarithmic term of the black hole entropy correction term is positive. This result is different from the known result at present. Our method is valid not only for four-dimensional spacetimes but also for higher-dimensional spacetimes. In the whole process, the physics idea is clear and calculation is simple. It offers a new way for studying the entropy correction of the complicated spacetime.
文摘We introduce an ultra high energy combined KAM-Rindler fractal spacetime quantum manifold, which increasingly resembles Einstein’s smooth relativity spacetime, with decreasing energy. That way we derive an effective quantum gravity energy-mass relation and compute a dark energy density in complete agreement with all cosmological measurements, specifically WMAP and type 1a supernova. In particular we find that ordinary measurable energy density is given by E1= mc2 /22 while the dark energy density of the vacuum is given by E2 = mc2 (21/22). The sum of both energies is equal to Einstein’s energy E = mc2. We conclude that E= mc2 makes no distinction between ordinary energy and dark energy. More generally we conclude that the geometry and topology of quantum entanglement create our classical spacetime and glue it together and conversely quantum entanglement is the logical consequence of KAM theorem and zero measure topology of quantum spacetime. Furthermore we show via our version of a Rindler hyperbolic spacetime that Hawking negative vacuum energy, Unruh temperature and dark energy are different sides of the same medal.
文摘Looped light in a recent sophisticated real three-slit experiment is interpreted as a strong justification of the old theoretical Peano-Hilbert spacetime model of Ord and El Naschie. This in turn entails the existence of extra fractal dimensions and consequently of real dark energy density in full agreement with previous analysis as well as accurate measurements and observations of COBE, WMAP, and the type 1a supernova.
