首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Review: Hamiltonian Linearization of the Rest-Frame Instant Form of Tetrad Gravity in a Completely Fixed 3-Orthogonal Gauge: A Radiation Gauge for Background-Independent Gravitational Waves in a Post-Minkowskian Einstein Spacetime
Authors:Juri Agresti  Roberto De Pietri  Luca Lusanna  Luca Martucci
Institution:(1) Dipartimento di Fisica, Universita' di Firenze, Polo Scientifico, via Sansone 1, 50019 Sesto Fiorentino, Italy;(2) Sezione INFN di Firenze, Polo Scientifico, via Sansone 1, 50019 Sesto Fiorentino, Italy
Abstract:In the framework of the rest-frame instant form of tetrad gravity, where the Hamiltonian is the weak ADM energy 
$$\hat E_{ADM}$$
, we define a special completely fixed 3-orthogonal Hamiltonian gauge, corresponding to a choice of non-harmonic 4-coordinates, in which the independent degrees of freedom of the gravitational field are described by two pairs of canonically conjugate Dirac observables (DO) 
$$r_{\overline a } (\tau ,\overrightarrow \sigma ),\pi \overline a (\tau ,\overrightarrow \sigma ),\overline a = 1,2$$
. We define a Hamiltonian linearization of the theory, i.e. gravitational waves, without introducing any background 4-metric, by retaining only the linear terms in the DO's in the super-hamiltonian constraint (the Lichnerowicz equation for the conformal factor of the 3-metric) and the quadratic terms in the DO's in 
$$\hat E_{ADM}$$
. We solve all the constraints of the linearized theory: this amounts to work in a well defined post-Minkowskian Christodoulou-Klainermann space-time. The Hamilton equations imply the wave equation for the DO's 
$$r_{\overline a } (\tau ,\overrightarrow \sigma ),$$
, which replace the two polarizations of the TT harmonic gauge, and that linearized Einstein's equations are satisfied. Finally we study the geodesic equation, both for time-like and null geodesics, and the geodesic deviation equation.
Keywords:Tetrad gravity  Dirac constraints  Hamiltonian Linearization
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号