Time-Variation of the Gravitational Constant and the Machian Solution in the Brans-Dicke Theory
نویسنده
چکیده
The Machian cosmological solution satisfying φ = O(ρ/ω) for the perfect-fluid with negative pressure is discussed. When the coefficient of the equation of state γ → −1/3, the gravitational constant approaches to constant. If we assume the present mass density ρ0 ∼ ρc (critical density), the parameter ǫ (γ = (ǫ− 1)/3) has a value of order 10−3 to support the present gravitational constant. The closed model is valid for ω < −3/2ǫ and exhibits the slow accelerating expansion. We understand why the coupling parameter |ω| is so large (ω ∼ −103). The time-variation of the gravitational constant ∣
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