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Bianchi Type I Cosmology in Generalized Saez-Ballester Theory via Noether Gauge Symmetry

In this paper, we investigate the generalized Saez-Ballester scalar-tensor theory of gravity via Noether gauge symmetry (NGS) in the background of Bianchi type I cosmological spacetime. We start with the Lagrangian of our model and calculate its gauge symmetries and corresponding invariant quantities. We obtain the potential function for the scalar field in the exponential form. For all the symmetries obtained, we determine the gauge functions corresponding to each gauge symmmetry which include constant and dynamic gauge. We discuss cosmological implications of our model and show that it is compatible with the observational data.Comment: 13 pages, 2 figures, accepted for publication in 'European Physical Journal C

A New Class of Bianchi Type-I Cosmological Models in Scalar-Tensor Theory of Gravitation and Late Time Acceleration

A new class of a spatially homogeneous and anisotropic Bianchi type-I cosmological models of the universe for perfect fluid distribution within the framework of scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett. 113:467, 1986) is investigated. To prevail the deterministic solutions we choose the different scale factors which yield time-dependent deceleration parameters (DP) representing models which generate a transition of the universe from the early decelerated phase to the recent accelerating phase. Three different physically viable models of the universe are obtained in which their anisotropic solutions may enter to some isotropic inflationary era. The modified Einstein's field equations are solved exactly and the models are found to be in good concordance with recent observations. Some physical and geometric properties of the models are also discussed.Comment: 16 pages, 8 figure

Accelerating Bianchi Type-V Cosmology with Perfect Fluid and Heat Flow in Saez-Ballester Theory

In this paper we discuss the law of variation of scale factor $a = (t^{k}e^{t})^{\frac{1}{n}}$ which yields a time-dependent deceleration parameter (DP) representing a new class of models that generate a transition of universe from the early decelerated phase to the recent accelerating phase. Exact solutions of Einstein's modified field equations with perfect fluid and heat conduction are obtained within the framework of Saez-Ballester scalar-tensor theory of gravitation and the model is found to be in good agreement with recent observations. We find, for n = 3, k = 1, the present value of DP in derived model as q_0 = -0.67 which is very near to the observed value of DP at present epoch. We find that the time-dependent DP is sensible for the present day Universe and give an earmark description of evolution of universe. Some physical and geometric properties of the models are also discussed.Comment: 12 pages, 5 figure

Axially Symmetric Holographic Dark Energy model with generalized Chaplygin gas in Brans-Dicke Theory of Gravitation

In this paper, we have investigated spatially homogeneous anisotropic axially symmetric holographic dark energy cosmological model with generalized Chaplygin gas is obtained in a scalar tensor theory of gravitation proposed by Brans and Dicke(1961). To obtain a determinate solution of the field equations we have used a power law between the metric potentials. It has been found that the anisotropic distribution of dark energy leads to the present accelerated expansion of Universe. All the models obtained and presented here are expanding, non-rotating and accelerating. Also some important features of the models including look-back time, distance modulus and luminosity distance versus red shift with their significances are discussed.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Spectroscopic Studies of Distorted Structure Bio-nano Molecules

AbstractIn this paper, we have introduced an algebraic technique to Bio Nano-molecules (Porphyrins & Fullerenes) family to determine the Vibrational spectra. An algebraic model of vibrations of polyatomic BioNano-molecules and present, as an example, the vibrational analysis of stretching modes of Nickel Octaethyl Porphyrin (Ni(OEP)), its Isotopomers and bionano molecules. The algebraic technique obtained the results are compared with experimental data; the results are showing good accuracy. Some reassignments of energy levels and predicts location of states not yet observed

Bianchi type-V modified holographic Ricci dark energy model in self creation theory of gravitation

Anisotropic and spatially homogeneous Bianchi type-V space time is considered in the presence of matter and anisotropic dark energy in Barberâ s (Gen. Relativ. Gravit. 14, 117, 1982) second self creation theory of gravitation. Anisotropic modified holographic Ricci dark energy model is presented using linearly varying deceleration parameter (Akarsu and Dereli: Int. J. Theor. Phys. 51, 612, 2012), energy density of modified holographic Ricci dark energy and relation between the metric potentials. Some physical and kinematical properties of the model are discussed through graphically by choosing suitable values to the parameters and which are found to be in good agreement with modern cosmological observational data.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Bianchi type- VI0 generalized ghost pilgrim dark energy in Brans-Dicke theory of gravitation

In this paper, we solve Brans-Dicke (BD) theory (Phys. Rev. D 24, 925, 1961) field equations for anisotropic Bianchi type VI0 space-time and discuss evolution of the expanding Universe. Here, we consider pressure less fluid and isotropic generalized ghost pilgrim dark energy (GGPDE) as the source of matter and dark energy respectively. To get the determinate solution of the field equations we have used (i) scalar expansion proportional to the shear scalar and (ii) scalar field (in BD theory) is proportional to average scale factor of the model. Some physical and geometrical properties of the model are also discussed.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author