TY - JOUR

T1 - Hyperbolic formulations and numerical relativity

T2 - II. Asymptotically constrained systems of Einstein equations

AU - Yoneda, Gen

AU - Shinkai, Hisa Aki

PY - 2001/2/7

Y1 - 2001/2/7

N2 - We study asymptotically constrained systems for numerical integration of the Einstein equations, which are intended to be robust against perturbative errors for the free evolution of the initial data. First, we examine the previously proposed 'λ system', which introduces artificial flows to constraint surfaces based on the symmetric hyperbolic formulation. We show that this system works as expected for the wave propagation problem in the Maxwell system and in general relativity using Ashtekar's connection formulation. Second, we propose a new mechanism to control the stability, which we call the 'adjusted system'. This is simply obtained by adding constraint terms in the dynamical equations and adjusting their multipliers. We explain why a particular choice of multiplier reduces the numerical errors from non-positive or pure-imaginary eigenvalues of the adjusted constraint propagation equations. This 'adjusted system' is also tested in the Maxwell system and in the Ashtekar system. This mechanism affects more than the system's symmetric hyperbolicity.

AB - We study asymptotically constrained systems for numerical integration of the Einstein equations, which are intended to be robust against perturbative errors for the free evolution of the initial data. First, we examine the previously proposed 'λ system', which introduces artificial flows to constraint surfaces based on the symmetric hyperbolic formulation. We show that this system works as expected for the wave propagation problem in the Maxwell system and in general relativity using Ashtekar's connection formulation. Second, we propose a new mechanism to control the stability, which we call the 'adjusted system'. This is simply obtained by adding constraint terms in the dynamical equations and adjusting their multipliers. We explain why a particular choice of multiplier reduces the numerical errors from non-positive or pure-imaginary eigenvalues of the adjusted constraint propagation equations. This 'adjusted system' is also tested in the Maxwell system and in the Ashtekar system. This mechanism affects more than the system's symmetric hyperbolicity.

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U2 - 10.1088/0264-9381/18/3/307

DO - 10.1088/0264-9381/18/3/307

M3 - Article

AN - SCOPUS:0035530682

VL - 18

SP - 441

EP - 462

JO - Classical and Quantum Gravity

JF - Classical and Quantum Gravity

SN - 0264-9381

IS - 3

ER -