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LRS Bianchi type-i Universe with Anisotropic Dark Energy in Lyra Geometry

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international Journal of Astronomy and Astrophysics 2011年第4期1卷 204-209页

作者： Kishor S. Adhav 不详

The exact solutions of the Einstein field equations for dark energy (DE) in Locally Rotationally Symmetric (LRS) Bianchi type-i metric under the assumption on the anisotropy of the fluid are obtained for exponential volumetric expansion within the frame work of Lyra manifold for uniform and time varying displacement field. The isotropy of the fluid and space is examined.

关键词： LRS Bianchi type-i Space-Time Perfect Fluid Anisotropic Dark Energy Lyra Geometry

Parameter Estimations for Generalized RayleighDistribution under Progressively type-i intervalCensored Data

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Open Journal of Statistics 2011年第2期1卷 46-57页

作者： Y. L. Lio Ding-Geng Chen Tzong-Ru Tsai 不详

in this paper, inference on parameter estimation of the generalized Rayleigh distribution are investigated for progressively type-i interval censored samples. The estimators of distribution parameters via maximum likelihood, moment method and probability plot are derived, and their performance are compared based on simulation results in terms of the mean squared error and bias. A case application of plasma cell myeloma data is used for illustrating the proposed estimation methods.

关键词： Maximum Likelihood Estimate Method of Moments EM Algorithm type-i interval Censoring

LRS Bianchi type-i Cosmological Model with Anisotropic Dark Energy and Special Form of Deceleration Parameter

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Journal of Modern Physics 2013年第8期4卷 1037-1040页

作者： Kishor Shankarrao Adhav Rajesh Purushottam Wankhade Abhijit Shankarrao Bansod Department of Mathematics Sant Gadge Baba Amravati University Amravati India

We have studied Locally Rotationally Symmetric (LRS) Bianchi type-i cosmological model filled with anisotropic fluid in general theory of relativity. The solutions of the field equations are obtained by using special form of deceleration parameter which gives early deceleration and late time accelerating cosmological model. The geometrical and physical aspect of the model is also studied.

关键词： LRS Bianchi type-i Space-Time Special Form of Deceleration Parameter Anisotropic Fluid Dark Energy isotropization

An Adjusted Model for Simple 1,2-Dyotropic Reactions. <i>Ab initio</i>MO and VB Considerations

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Open Journal of Physical Chemistry 2013年第3期3卷 119-125页

作者： Henk M. Buck Kasteel Twikkelerf 94 Tilburg The Netherlands

With an adjusted model, we reconsider simple 1,2-dyotropic reactions with the introduction of a concept based on the intramolecular dynamics of a tetrahedron (van ’t Hoff modeling). in fact the dyotropic reactions are strongly related to conversions originated from neighbouring group participation or anchimeric assistance, defined as the interaction of a center with a lone pair of electrons in an atom and the electrons present in aδor π bond. The researchful 1,2-dyotropic reactions, based on the 1,2-interchange of halogens, methyl and hydrogen taking place in a concerted fashion, are in competition with the two-step reaction in which the neighbouring group participation or anchimeric assistance comes to full expression by ionic dissociation of the other exchangeable (halogen) atom. As to be expected there is an essential difference between halogen or methyl exchange regarding the number of electrons participating in the transition state. This aspect becomes evident in the geometries of the corresponding transition state geometries. in this paper we refer to ab initio MO calculations and VB considerations. We consider the 1,2-halogen exchange as a combination of two SN2 reactions each containing four electrons. The van ’t Hoff dynamics appears a useful model in order to illustrate the computations in a straightforward manner.

关键词： type-i Dyotropic Reactions MO Calculations Van ’t Hoff Model Considerations Halogen and Methyl Exchange Conflicting Models

Bulk Viscous Anisotropic Cosmological Models with Dynamical Cosmological Parameters G and ∧

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Natural Science 2015年第4期7卷 179-189页

作者： S. Kotambkar G. P. Singh R. Kelkar Department of Mathematics Laxminarayan Institute of Technology Rashtrasant Tukadoji Maharaj Nagpur University Nagpur India Department of Mathematics Visvesvaraya National Institute of Technology Nagpur India Department of Mathematics S. B. Jain Institute of Technology Management and Research Nagpur India

This paper deals with the Bianchi type i anisotropic models of the universe, filled with a bulk viscous cosmic fluid, in the presence of variable gravitational and cosmological constants. Some exact solutions of Einstein’s gravitational field equations with bulk viscosity, gravitational and cosmological constants have been obtained. Several well known forms of cosmological terms have been considered to discuss the effect of cosmological variables. The new cosmological models presented in this paper approaches to isotropic model with evolution of universe. The physical and dynamical properties of the models have also been discussed.

关键词： Bianchi type-i Bulk Viscosity Gravitational and Cosmological “Constant”

2-A Cosmological Model with Varying G and ∧ in General Relativity

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Open Journal of Applied Sciences 2013年第1期3卷 74-78页

作者： Harpreet R. K. Tiwari H. S. Sahota Department of Applied Sciences Sant Baba Bhag Singh Institute of Engineering & Technology Jalandhar India Goverment Engineering College Reva M.P. India

Spatially homogeneous and anisotropic Cosmological models play a significant role in the description of the early stages of evolution of the universe. The problem of the cosmological constant is still unsettled. The authors recently considered time dependent G and L with Bianchi type–i Cosmological model .We considered in this paper homogeneous Bianchi type -i space-time with variable G and L containing matter in the form of a perfect fluid assuming the cosmological term proportional to R-2 (where R is scale factor). initially the model has a point type singularity, gravitational constant G (t) is decreasing and cosmological constant L is infinite at this time. When time increases L decreases. Unlike in some earlier works we have neither assumed equation of state nor particular form of G. The model does not approach isotropy, if ‘t’ is small .The model is quasi-isotropic for large value of ‘t’.

关键词： Bianchi type-i Universe Varying G and ∧ Cosmology

1-A Cosmological Model with Varying G and ∧ in General Relativity

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Open Journal of Applied Sciences 2013年第1期3卷 89-93页

作者： Harpreet R. K. Tiwari H. S. Sahota Department of Applied Sciences Sant Baba Bhag Singh Institute of Engineering & Technology Khiala Padhiana Jalandhar- 144030Punjab India

in this paper homogeneous Bianchi type -i space-time with variable G and L containing matter in the form of a perfect fluid assuming the cosmological term proportional to H2 (where H is Hubble Parameter). initially the model has a point type singularity, gravitational constant G (t) is decreasing and cosmological constant L is infinite at this time. When time increases,L decrease. The model does not approach isotropy, if it is small. The model is quasi-isotropic for large value of it.

关键词： Bianchi type-i Universe Varying G and ∧ Cosmology Hubble Parameter