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Gerhard Schafer - One of the best experts on this subject based on the ideXlab platform.
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elimination of the spin supplementary condition in the effective field theory approach to the post newtonian approximation
Annals of Physics, 2012Co-Authors: Steven Hergt, Jan Steinhoff, Gerhard SchaferAbstract:Abstract The present paper addresses open questions regarding the handling of the spin supplementary condition within the effective field theory approach to the post-Newtonian approximation. In particular it is shown how the covariant spin supplementary condition can be eliminated at the level of the potential (which is subtle in various respects) and how the dynamics can be cast into a fully reduced Hamiltonian Form. Two different methods are used and compared, one based on the well-known Dirac bracket and the other based on an action principle. It is discussed how the latter approach can be used to improve the Feynman rules by Formulating them in terms of reduced canonical spin variables.
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spin squared Hamiltonian of next to leading order gravitational interaction
Physical Review D, 2008Co-Authors: Jan Steinhoff, Steven Hergt, Gerhard SchaferAbstract:The static, i.e., linear momentum independent, part of the next-to-leading order (NLO) gravitational spin(1)-spin(1) interaction Hamiltonian within the post-Newtonian (PN) approximation is calculated from a three-dimensional covariant ansatz for the Hamilton constraint. All coefficients in this ansatz can be uniquely fixed for black holes. The resulting Hamiltonian fits into the canonical Formalism of Arnowitt, Deser, and Misner (ADM) and is given in their transverse-traceless (ADMTT) gauge. This completes the recent result for the momentum dependent part of the NLO spin(1)-spin(1) ADM Hamiltonian for binary black holes (BBH). Thus, all PN NLO effects up to quadratic order in spin for BBH are now given in Hamiltonian Form in the ADMTT gauge. The equations of motion resulting from this Hamiltonian are an important step toward more accurate calculations of templates for gravitational waves.
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next to leading order gravitational spin 1 spin 2 dynamics in Hamiltonian Form
Physical Review D, 2008Co-Authors: Jan Steinhoff, Steven Hergt, Gerhard SchaferAbstract:Based on recent developments by the authors a next-to-leading order spin(1)-spin(2) Hamiltonian is derived for the first time. The result is obtained within the canonical Formalism of Arnowitt, Deser, and Misner (ADM) utilizing their generalized isotropic coordinates. A comparison with other methods is given.
Jan Steinhoff - One of the best experts on this subject based on the ideXlab platform.
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elimination of the spin supplementary condition in the effective field theory approach to the post newtonian approximation
Annals of Physics, 2012Co-Authors: Steven Hergt, Jan Steinhoff, Gerhard SchaferAbstract:Abstract The present paper addresses open questions regarding the handling of the spin supplementary condition within the effective field theory approach to the post-Newtonian approximation. In particular it is shown how the covariant spin supplementary condition can be eliminated at the level of the potential (which is subtle in various respects) and how the dynamics can be cast into a fully reduced Hamiltonian Form. Two different methods are used and compared, one based on the well-known Dirac bracket and the other based on an action principle. It is discussed how the latter approach can be used to improve the Feynman rules by Formulating them in terms of reduced canonical spin variables.
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spin squared Hamiltonian of next to leading order gravitational interaction
Physical Review D, 2008Co-Authors: Jan Steinhoff, Steven Hergt, Gerhard SchaferAbstract:The static, i.e., linear momentum independent, part of the next-to-leading order (NLO) gravitational spin(1)-spin(1) interaction Hamiltonian within the post-Newtonian (PN) approximation is calculated from a three-dimensional covariant ansatz for the Hamilton constraint. All coefficients in this ansatz can be uniquely fixed for black holes. The resulting Hamiltonian fits into the canonical Formalism of Arnowitt, Deser, and Misner (ADM) and is given in their transverse-traceless (ADMTT) gauge. This completes the recent result for the momentum dependent part of the NLO spin(1)-spin(1) ADM Hamiltonian for binary black holes (BBH). Thus, all PN NLO effects up to quadratic order in spin for BBH are now given in Hamiltonian Form in the ADMTT gauge. The equations of motion resulting from this Hamiltonian are an important step toward more accurate calculations of templates for gravitational waves.
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next to leading order gravitational spin 1 spin 2 dynamics in Hamiltonian Form
Physical Review D, 2008Co-Authors: Jan Steinhoff, Steven Hergt, Gerhard SchaferAbstract:Based on recent developments by the authors a next-to-leading order spin(1)-spin(2) Hamiltonian is derived for the first time. The result is obtained within the canonical Formalism of Arnowitt, Deser, and Misner (ADM) utilizing their generalized isotropic coordinates. A comparison with other methods is given.
Steven Hergt - One of the best experts on this subject based on the ideXlab platform.
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elimination of the spin supplementary condition in the effective field theory approach to the post newtonian approximation
Annals of Physics, 2012Co-Authors: Steven Hergt, Jan Steinhoff, Gerhard SchaferAbstract:Abstract The present paper addresses open questions regarding the handling of the spin supplementary condition within the effective field theory approach to the post-Newtonian approximation. In particular it is shown how the covariant spin supplementary condition can be eliminated at the level of the potential (which is subtle in various respects) and how the dynamics can be cast into a fully reduced Hamiltonian Form. Two different methods are used and compared, one based on the well-known Dirac bracket and the other based on an action principle. It is discussed how the latter approach can be used to improve the Feynman rules by Formulating them in terms of reduced canonical spin variables.
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spin squared Hamiltonian of next to leading order gravitational interaction
Physical Review D, 2008Co-Authors: Jan Steinhoff, Steven Hergt, Gerhard SchaferAbstract:The static, i.e., linear momentum independent, part of the next-to-leading order (NLO) gravitational spin(1)-spin(1) interaction Hamiltonian within the post-Newtonian (PN) approximation is calculated from a three-dimensional covariant ansatz for the Hamilton constraint. All coefficients in this ansatz can be uniquely fixed for black holes. The resulting Hamiltonian fits into the canonical Formalism of Arnowitt, Deser, and Misner (ADM) and is given in their transverse-traceless (ADMTT) gauge. This completes the recent result for the momentum dependent part of the NLO spin(1)-spin(1) ADM Hamiltonian for binary black holes (BBH). Thus, all PN NLO effects up to quadratic order in spin for BBH are now given in Hamiltonian Form in the ADMTT gauge. The equations of motion resulting from this Hamiltonian are an important step toward more accurate calculations of templates for gravitational waves.
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next to leading order gravitational spin 1 spin 2 dynamics in Hamiltonian Form
Physical Review D, 2008Co-Authors: Jan Steinhoff, Steven Hergt, Gerhard SchaferAbstract:Based on recent developments by the authors a next-to-leading order spin(1)-spin(2) Hamiltonian is derived for the first time. The result is obtained within the canonical Formalism of Arnowitt, Deser, and Misner (ADM) utilizing their generalized isotropic coordinates. A comparison with other methods is given.
Alasdair J Routh - One of the best experts on this subject based on the ideXlab platform.
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the Hamiltonian Form of three dimensional chern simons like gravity models
2014Co-Authors: E Bergshoeff, Alasdair J Routh, Olaf Hohm, Wout Merbis, P K TownsendAbstract:A wide class of three-dimensional gravity models can be put into "Chern-Simons-like" Form. We perForm a Hamiltonian analysis of the general model and then specialise to Einstein-Cartan Gravity, General Massive Gravity, the recently proposed Zwei-Dreibein Gravity and a further parity violating generalisation combining the latter two.
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Hamiltonian Form of topologically massive supergravity
Physical Review D, 2013Co-Authors: Alasdair J RouthAbstract:We construct a “Chern-Simons-like” action for N = 1 Topologically Massive Supergravity from the Chern-Simons actions of N = 1 Supergravity and ConFormal Supergravity. We convert this action into Hamiltonian Form and use this to demonstrate that the theory propagates a single massive 2, 3 � supermultiplet.
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on the Hamiltonian Form of 3d massive gravity
Physical Review D, 2012Co-Authors: Olaf Hohm, Alasdair J Routh, Paul K Townsend, Baocheng ZhangAbstract:We present a Chern-Simons-like action for the general massive gravity model propagating two spin-2 modes with independent masses in three spacetime dimensions (3D), and we use it to find a simple Hamiltonian Form of this model. The number of local degrees of freedom, determined by the dimension of the physical phase space, agrees with a linearized analysis except in some limits, in particular that yielding topologically new massive gravity, which therefore suffers from a linearization instability.
Rick Salmon - One of the best experts on this subject based on the ideXlab platform.
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shallow water equations with a complete coriolis force and topography
Physics of Fluids, 2005Co-Authors: Paul J Dellar, Rick SalmonAbstract:This paper derives a set of two-dimensional equations describing a thin inviscid fluid layer flowing over topography in a frame rotating about an arbitrary axis. These equations retain various terms involving the locally horizontal components of the angular velocity vector that are discarded in the usual shallow water equations. The obliquely rotating shallow water equations are derived both by averaging the three-dimensional equations and from an averaged Lagrangian describing columnar motion using Hamilton’s principle. They share the same conservation properties as the usual shallow water equations, for the same energy and modified Forms of the momentum and potential vorticity. They may also be expressed in noncanonical Hamiltonian Form using the usual shallow water Hamiltonian and Poisson bracket. The conserved potential vorticity takes the standard shallow water Form, but with the vertical component of the rotation vector replaced by the component locally normal to the surface midway between the upper and lower boundaries.
