17,198 research outputs found
Inflationary phase in Generalized Brans-Dicke theory
We find a solution for exponential inflation in a Brans-Dicke generalized
model, where the coupling "constant " is variable. While in General Relativity
the equation of state is p is equal to minus rho, here we find p proportional
to rho, where the proportionality constant is smaller than -2/3. The negativity
of cosmic pressure implies acceleration of the expansion, even with lambda < 0
>.Comment: International Journal of Theoretical Physics, to be publishe
General Relativistic Singularity-Free Cosmological Model
We "explain", using a Classical approach, how the Universe was created out of
"nothing", i.e., with no input of initial energy nor mass. The inflationary
phase, with exponential expansion, is accounted for, automatically, by our
equation of state for the very early Universe. This is a Universe with
no-initial infinite singularity of energy density.Comment: Astrophysics and Space Science, 321,157 (2009
Automated dynamic analytical model improvement for damped structures
A method is described to improve a linear nonproportionally damped analytical model of a structure. The procedure finds the smallest changes in the analytical model such that the improved model matches the measured modal parameters. Features of the method are: (1) ability to properly treat complex valued modal parameters of a damped system; (2) applicability to realistically large structural models; and (3) computationally efficiency without involving eigensolutions and inversion of a large matrix
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