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Motivated by our attempt to understand the question of angular momentum of a relativistic rotating source carried away by gravitational waves, in the asymptotic regime near future null infinity of the Kerr metric, a family of null hypersurfaces intersecting null infinity in shearfree (good) cuts are constructed by means of asymptotic expansion of the(More)
With the rapid development of information technology (IT), IT education has also become a life-long education. The web-based network education has been emerging as one of the most promising IT education models. After analyzing the present problems of existing web-based IT education platform (ITEP), this paper briefly discusses the major characteristics of(More)
The Noether current and its variation relation with respect to diffeomorphism invariance of gravitational theories have been derived from the horizontal variation and vertical-horizontal bi-variation of the Lagrangian, respectively. For Einstein’s GR in the stationary, axisymmetric black holes, the mass formula in vacuum can be derived from this Noether(More)
We re-express the Kerr metric in standard Bondi-Saches’ coordinate near null infinity I+. Using the uniqueness result of characteristic initial value problem, we prove the Kerr metric is the only asymptotic flat, stationary, axial symmetric, Type-D solution of vacuum Einstein equation. The Taylor series of Kerr space-time is expressed in terms of B-S(More)
We consider the general asymptotic expression of stationary space-time. Using Killing equation, we reduce the dynamical freedom of Einstein equation to the ingoing gravitational wave Ψ0. The general form of this function can be got. With the help of asymptotically algebraic special condition, we prove that all Newman-Penrose constants vanish. PACS number :(More)
The Noether-charge realization and the Hamiltonian realization for the diff(M) algebra in diffeomorphism invariant gravitational theories are studied in a covariant formalism. For the Killing vector fields, the Nother-charge realization leads to the mass formula as an entire vanishing Noether charge for the vacuum black hole spacetimes in general relativity(More)
In this paper, we propose a construction method of quasi-cyclic low-density parity-check (QC-LDPC) codes with multi-weight circulants (MQC-LDPC codes) which is suitable for high-rate LDPC codes with moderate length. MQC-LDPC codes can achieve better degree distributions, Hamming weight distributions, and stopping set weight distributions than conventional(More)
It is shown in the covariant phase space formalism that the Noether charges with respect to the diffeomorphism generated by vector fields and their horizontal variations in general relativity form a diffeomorphism algebra. It is also shown with the help of the null tetrad which is well defined everywhere that the central term of the reduced diffeomorphism(More)
The entropy bound conjecture concerning black hole dynamical horizons is proved. The conjecture states, if a dynamical horizon, DH , is bounded by two surfaces with areas of AB and AB′ (AB′ > AB), then the entropy, SD, that crosses DH must satisfy SD ≤ 1 4 (AB′ − AB). We show that this conjecture is implied by the generalized Bousso bound. Consequently, the(More)