نتایج جستجو برای: einstein field equations

تعداد نتایج: 1015110  

حنیف محمدپور, , محمدحسین دهقانی, ,

 In this paper we consider the action of higher derivative gravity up to the second order terms in the scalars made from the Ricci scalar, Ricci and Riemann tensors. We use the Bach- Lanczos identity of the Weyl tensor in four dimensions and show that the solutions of 4-dimensional Einstein equations with cosmological constant term in vacuum, which are known as Einstein metrics, satisfy the fie...

Journal: :The European Physical Journal C 2018

2008
Dan N. Vollick

The field equations associated with the Born-Infeld-Einstein action are derived using the Palatini variational technique. In this approach the metric and connection are varied independently and the Ricci tensor is generally not symmetric. For sufficiently small curvatures the resulting field equations can be divided into two sets. One set, involving the antisymmetric part of the Ricci tensor Rμ...

2001
Stoytcho S. Yazadjiev

We present solution generating methods which allow us to construct exact static solutions to the equations of four-dimensional Einstein-MaxwellDilaton gravity starting with arbitrary static solutions to the pure vacuum Einstein equations, Einstein-dilaton or Einstein-Maxwell equations. In four dimensions the field equations of the Einstein-Maxwell-dilaton gravity with arbitrary dilaton coupling...

2001
S. Yazadjiev

We present solution generating methods which allow to construct exact static solutions to the equations of four-dimensional Einstein-Maxwell-Dilaton gravity starting with arbitrary static solutions to the pure vacuum Einstein equations, Einstein-dilaton or Einstein-Maxwell equations. In four dimensions the field equations of the Einstein-Maxwell-dilaton gravity with arbitrary dilaton coupling p...

2008
Amir H. Abbassi

According to Birkhoff’s theorem the only spherically symmetric solution of the vacuum Einstein field equations is the Schwarzschild solution. Inspite of imposing asymptotically flatness and staticness as initial conditions we obtain that these equations have general solutions with the Schwarzschild metric as merely a special and simplest form of them. It is possible to have perfect and smooth m...

2005
Dan N. Vollick

The field equations associated with the Born-Infeld-Einstein action including matter are derived using a Palatini variational principle. Scalar, electromagnetic, and Dirac fields are considered. It is shown that an action can be chosen for the scalar field that produces field equations identical to the usual Einstein field equations minimally coupled to a scalar field. In the electromagnetic an...

Journal: :Astrophysics and Space Science 1981

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