Yazar "Yilmaz, I." seçeneğine göre listele

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    Dark Matter And Dark Energy Solutions Using By Observational Evidence
    (Amer Inst Physics, 2018) Demirel, E. C. Gunay; Yilmaz, I.
    In this study, we examine dark energy, dark matter and baryonic matter in FRW by observational evidences. Also we study our model by considering possible dark energy candidates such as Phantom energy. Obtained solutions show that dark energy candidate may be phantom energy depending on accuracy of today's observation.
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    Five-dimensional cosmological model with variable G and ?
    (Iop Publishing Ltd, 2007) Baysal, H.; Yilmaz, I.
    Eintein's field equations with G and Lambda both varying with time are considered in the presence of a perfect fluid for five-dimensional cosmological model in a way which conserves the energy momentum tensor of the matter content. Several sets of explicit solutions in the five-dimensional Kaluza-Klein type cosmological models G and Lambda are obtained. The diminishment of extra dimension with the evolution of the universe for the five-dimenonal model is exhibited. The physical properties of the model is exhibited. The physical properties of the models are examined.
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    Moller energy-momentum complex in general relativity for higher dimensional universes
    (Iop Publishing Ltd, 2007) Ayguen, M.; Ayguen, S.; Yilmaz, I.; Baysal, H.; Tarhan, I.
    Using the Moller energy momentum definition in general relativity (GR) we calculate the total energy momentum distribution associated with (n + 2)-dimensional homogeneous and isotropic model of the universe. It is found that total energy of Moller is vanishing in (n + 2) dimensions everywhere but n-momentum components of Moller in (n + 2) dimensions are different from zero. Also, we evaluate the static Einstein Universe, FRW universe and de Sitter universe in four dimensions by using (n + 2)-type -metric, then calculate the Moller energy momentum distribution of these spacetimes. However, our results are consistent with the results of Banerjee and Sen, Xulu, Radinschi, Vargas, Cooperstock-Israelit, Aygun et at., Rosen, and Johri et al. in four dimensions.
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    Reply to comments on 'Five-dimensional cosmological model with variable g and ?'
    (Iop Publishing Ltd, 2008) Baysal, H.; Yilmaz, I.
    The results of ours are correct. There are misprints in the sign of Eq. (11) and the factor (n - 1) in Eq. (12) in our paper [Chin. Phys. Lett. 24 (2007) 2185]. We did not study special values of n = 1 and n = -3.
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    String cloud and domain walls with quark matter in 5-D Kaluza-Klein cosmological model
    (Springer/Plenum Publishers, 2006) Yilmaz, I.
    In this study Kaluza-Klein Cosmological solutions are obtained for quark matter coupled to the string cloud and domain wall in the context of general relativity. For this purpose Einstein field equations are solved by using anisotropy feature of the universe in the five-dimensional Kaluza-Klein Cosmological model. Also, the features of obtained solutions are discussed.