We extend standard linear perturbations of a Schwarzschild black hole by Chandrasekhar to Bondi frame by transforming both even and odd parity perturbations when angular momentum l = 2.
In a vacuum spacetime equipped with the Bondi’s radiating metric which is asymptotically flat at spatial infinity including gravitational radiation (Condition D),we establish the relation between the ADM total energy...In a vacuum spacetime equipped with the Bondi’s radiating metric which is asymptotically flat at spatial infinity including gravitational radiation (Condition D),we establish the relation between the ADM total energy-momentum and the Bondi energy-momentum for perturbed radiative spatial infinity.The perturbation is given by defining the"real"time as the sum of the retarded time,the Euclidean distance and certain function f.展开更多
In this paper,we show that the peeling property still holds for Bondi-Sachs metrics with nonzero cosmological constants under the boundary condition given by Sommerfeld's radiation condition together with three no...In this paper,we show that the peeling property still holds for Bondi-Sachs metrics with nonzero cosmological constants under the boundary condition given by Sommerfeld's radiation condition together with three nontrivialΛ-independent functions B,a and b.This should indicate that the new boundary condition is natural.Moreover,we construct some nonstationary vacuum Bondi-Sachs metrics without Bondi news,whose Newman-Penrose quantities fall faster than usual.This provides a new feature of gravitational waves for nonzero cosmological constants.展开更多
We discuss tile Hamiltonian formulation of gravity in four-dimensional spacetime under Bondi-like coordinates {v,r,xa,a=2,3}. In Bondi-like coordinates, the three-dimensional hypersurface is a null hypersurface, and t...We discuss tile Hamiltonian formulation of gravity in four-dimensional spacetime under Bondi-like coordinates {v,r,xa,a=2,3}. In Bondi-like coordinates, the three-dimensional hypersurface is a null hypersurface, and the evolution direction is the advanced time v. The internal symmetry group SO（1,3） of the four-dimensional spacetime is decomposed into SO（1,1）, SO（2）, and T^±（2）, whose Lie algebra s0（1,3） is decomposed into s0（1,1）, s0（2）, and t^± （2） correspondingly. The SO（1,1） symmetry is very obvious in this type of decomposition, which is very useful in s0（1,1） BF theory. General relativity can be reformulated as the four-dimensional coframe （eμ^I） and connection （ωμ^IJ） dynamics of gravity based on this type of decomposition in the Bondi-like coordinate system. The coframe consists of two null 1-forms e-, e＋ and two spacelike 1-forms e2, e3. The Palatial action is used. The Hamiltonian analysis is conducted by Dirac＇s methods. The consistency analysis of constraints has been done completely. Among the constraints, there are two scalar constraints and one two-dimensional vector constraint. The torsion-free conditions are acquired from the consistency conditions of the primary constraints about πIJ^μg. The consistency conditions of the primary constraints πIJ^0= 0 can be reformulated as Gauss constraints. The conditions of the Lagrange multipliers have been acquired. The Poisson brackets among the constraints have been calculated. There are 46 constraints including 6 first-class constraints πIJ^0= 0 and 40 second-class constraints. The local physical degrees of freedom is 2. The integrability conditions of Lagrange multipliers no, 10, and eA are Ricci identities. The equations of motion of the canonical variables have also been shown.展开更多
The Open Mobile Terminal Platform (OMTP) is a global forum made by telecommunications providers to promote user-oriented mobile services and data businesses. Devised by OMTP, BONDI is a browser-based application or a ...The Open Mobile Terminal Platform (OMTP) is a global forum made by telecommunications providers to promote user-oriented mobile services and data businesses. Devised by OMTP, BONDI is a browser-based application or a mobile Web run-time platform to help widgets make good use of the functions of mobile devices in a secure way. BONDI enables applications programmed with Web standard technologies such as HTML, JavaScript, CSS, and AJAX to reach the internal functions of mobile devices. Since BONDI, which is not just a simple network application, can reach the internal resources of devices in standard ways, it enables the application and widgets to be developed regardless of the operating system (OS) or platform. Web browser-based widgets are vulnerable to the network environment, and their execution speed can be slowed as the operations of the widgets or applications become heavy. Compared with the native widgets inside the device, however, those Web widgets will be continuously used thanks to the user-friendly simple interface and the faster speed in using Web resources. This study deals with a method to effectively operate and manage the resources of OMTP BONDI Web widget and provides improved results based on running performance evaluation experiments. The experiments were carried out to improve the entire operating time by enhancing the module-loading speed. In this regard, only indispensable modules were allowed to be loaded while the BONDI widget was underway. For this purpose, the widget resource list, which can make the operating speed of the BONDI widget faster, was redefined while a widget cache was employed. In addition, the widget box, a management tool for removed widgets, was devised to store temporarily idle widgets.展开更多
The Hamiltonian analysis for a 3-dimensional connection dynamics of so(1, 2), spanned by {L_(-+), L_(-2), L_(+2)}instead of {L_(01), L_(02), L_(12)}, is first conducted in a Bondi-like coordinate system. The symmetry ...The Hamiltonian analysis for a 3-dimensional connection dynamics of so(1, 2), spanned by {L_(-+), L_(-2), L_(+2)}instead of {L_(01), L_(02), L_(12)}, is first conducted in a Bondi-like coordinate system. The symmetry of the system is clearly presented. A null coframe with 3 independent variables and 9 connection coefficients are treated as basic configuration variables. All constraints and their consistency conditions, the solutions of Lagrange multipliers as well as the equations of motion are presented. There is no physical degree of freedom in the system. The Ban?ados–Teitelboim–Zanelli(BTZ)spacetime is discussed as an example to check the analysis. Unlike the ADM formalism, where only non-degenerate geometries on slices are dealt with and the Ashtekar formalism, where non-degenerate geometries on slices are mainly concerned though the degenerate geometries may be studied as well, in the present formalism the geometries on the slices are always degenerate though the geometries for the spacetime are not degenerate.展开更多
In this paper, we extend Parikh＇ recent work to the Vaidya-de Sitter black hole which is non-stationary. We view Hawking radiation as a tunnelling process across the event horizon and calculate the tunnelling probabi...In this paper, we extend Parikh＇ recent work to the Vaidya-de Sitter black hole which is non-stationary. We view Hawking radiation as a tunnelling process across the event horizon and calculate the tunnelling probability when the particle crosses the event horizon. From the tunnelling probability we also find a leading correction to the semiclassical emission rate.展开更多
We derive two new retarded solutions in the teleparallel theory equivalent to general relativity （TEGR）. One of these solutions gives a divergent energy. Therefore, we use the regularized expression of the gravitati...We derive two new retarded solutions in the teleparallel theory equivalent to general relativity （TEGR）. One of these solutions gives a divergent energy. Therefore, we use the regularized expression of the gravitational energymomentum tensor, which is a coordinate dependent. A detailed analysis of the loss of the mass of Bondi space-time is carried out using the flux of the gravitational energy-momentum.展开更多
文摘We extend standard linear perturbations of a Schwarzschild black hole by Chandrasekhar to Bondi frame by transforming both even and odd parity perturbations when angular momentum l = 2.
基金partially supported by the National Natural Science Foundation of China(Grant Nos.10231050,10421001)the National Key Basic Research Project of China(Grant No.2006CB805905)the Innovation Project of Chinese Academy of Sciences
文摘In a vacuum spacetime equipped with the Bondi’s radiating metric which is asymptotically flat at spatial infinity including gravitational radiation (Condition D),we establish the relation between the ADM total energy-momentum and the Bondi energy-momentum for perturbed radiative spatial infinity.The perturbation is given by defining the"real"time as the sum of the retarded time,the Euclidean distance and certain function f.
基金supported by National Natural Science Foundation of China(Grant Nos.11571345 and 11731001)Hua Loo-Keng Key Laboratory of Mathematics,National Center for Mathematics and Interdisciplinary Sciences,Center for Excellence in Mathematical Sciences,Hua Loo-Keng Center for Mathematical Sciences of Chinese Academy of Sciences。
文摘In this paper,we show that the peeling property still holds for Bondi-Sachs metrics with nonzero cosmological constants under the boundary condition given by Sommerfeld's radiation condition together with three nontrivialΛ-independent functions B,a and b.This should indicate that the new boundary condition is natural.Moreover,we construct some nonstationary vacuum Bondi-Sachs metrics without Bondi news,whose Newman-Penrose quantities fall faster than usual.This provides a new feature of gravitational waves for nonzero cosmological constants.
基金Supported by the National Natural Science Foundation of China(11690022)
文摘We discuss tile Hamiltonian formulation of gravity in four-dimensional spacetime under Bondi-like coordinates {v,r,xa,a=2,3}. In Bondi-like coordinates, the three-dimensional hypersurface is a null hypersurface, and the evolution direction is the advanced time v. The internal symmetry group SO（1,3） of the four-dimensional spacetime is decomposed into SO（1,1）, SO（2）, and T^±（2）, whose Lie algebra s0（1,3） is decomposed into s0（1,1）, s0（2）, and t^± （2） correspondingly. The SO（1,1） symmetry is very obvious in this type of decomposition, which is very useful in s0（1,1） BF theory. General relativity can be reformulated as the four-dimensional coframe （eμ^I） and connection （ωμ^IJ） dynamics of gravity based on this type of decomposition in the Bondi-like coordinate system. The coframe consists of two null 1-forms e-, e＋ and two spacelike 1-forms e2, e3. The Palatial action is used. The Hamiltonian analysis is conducted by Dirac＇s methods. The consistency analysis of constraints has been done completely. Among the constraints, there are two scalar constraints and one two-dimensional vector constraint. The torsion-free conditions are acquired from the consistency conditions of the primary constraints about πIJ^μg. The consistency conditions of the primary constraints πIJ^0= 0 can be reformulated as Gauss constraints. The conditions of the Lagrange multipliers have been acquired. The Poisson brackets among the constraints have been calculated. There are 46 constraints including 6 first-class constraints πIJ^0= 0 and 40 second-class constraints. The local physical degrees of freedom is 2. The integrability conditions of Lagrange multipliers no, 10, and eA are Ricci identities. The equations of motion of the canonical variables have also been shown.
基金Project supported by the Research Fund of Dankook University in 2009
文摘The Open Mobile Terminal Platform (OMTP) is a global forum made by telecommunications providers to promote user-oriented mobile services and data businesses. Devised by OMTP, BONDI is a browser-based application or a mobile Web run-time platform to help widgets make good use of the functions of mobile devices in a secure way. BONDI enables applications programmed with Web standard technologies such as HTML, JavaScript, CSS, and AJAX to reach the internal functions of mobile devices. Since BONDI, which is not just a simple network application, can reach the internal resources of devices in standard ways, it enables the application and widgets to be developed regardless of the operating system (OS) or platform. Web browser-based widgets are vulnerable to the network environment, and their execution speed can be slowed as the operations of the widgets or applications become heavy. Compared with the native widgets inside the device, however, those Web widgets will be continuously used thanks to the user-friendly simple interface and the faster speed in using Web resources. This study deals with a method to effectively operate and manage the resources of OMTP BONDI Web widget and provides improved results based on running performance evaluation experiments. The experiments were carried out to improve the entire operating time by enhancing the module-loading speed. In this regard, only indispensable modules were allowed to be loaded while the BONDI widget was underway. For this purpose, the widget resource list, which can make the operating speed of the BONDI widget faster, was redefined while a widget cache was employed. In addition, the widget box, a management tool for removed widgets, was devised to store temporarily idle widgets.
基金Supported by National Natural Science Foundation of China under Grant Nos.11275207 and 11690022
文摘The Hamiltonian analysis for a 3-dimensional connection dynamics of so(1, 2), spanned by {L_(-+), L_(-2), L_(+2)}instead of {L_(01), L_(02), L_(12)}, is first conducted in a Bondi-like coordinate system. The symmetry of the system is clearly presented. A null coframe with 3 independent variables and 9 connection coefficients are treated as basic configuration variables. All constraints and their consistency conditions, the solutions of Lagrange multipliers as well as the equations of motion are presented. There is no physical degree of freedom in the system. The Ban?ados–Teitelboim–Zanelli(BTZ)spacetime is discussed as an example to check the analysis. Unlike the ADM formalism, where only non-degenerate geometries on slices are dealt with and the Ashtekar formalism, where non-degenerate geometries on slices are mainly concerned though the degenerate geometries may be studied as well, in the present formalism the geometries on the slices are always degenerate though the geometries for the spacetime are not degenerate.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10373003, 10475013 and the State Key Development for Basic Research of China （Grant No 2003CB716300）.Acknowledgement We would like to thank Guihua Tian for help.
文摘In this paper, we extend Parikh＇ recent work to the Vaidya-de Sitter black hole which is non-stationary. We view Hawking radiation as a tunnelling process across the event horizon and calculate the tunnelling probability when the particle crosses the event horizon. From the tunnelling probability we also find a leading correction to the semiclassical emission rate.
文摘We derive two new retarded solutions in the teleparallel theory equivalent to general relativity （TEGR）. One of these solutions gives a divergent energy. Therefore, we use the regularized expression of the gravitational energymomentum tensor, which is a coordinate dependent. A detailed analysis of the loss of the mass of Bondi space-time is carried out using the flux of the gravitational energy-momentum.
