Higher Dimensional Bianchi Type-III String Cosmological Models in Lyra Geometry

Here we studied Bianchi type-III string cosmological models generated by means of a cloud of strings with particles connected to them in the framework of Lyra geometry considering five-dimensional space-time. To obtain the exact solutions of field equations we consider that the shear scalar and the scalar expansion are proportional, σ∞θ which leads to D=cn and secondly we adopt the assumption considering the Reddy String Condition, ρ+λ=0. From the two different cases obtained here, first case leads to the Bianchi type-III string cosmological model in Lyra geometry in five-dimensional space-time and the second case leads to the five-dimensional vacuum universe in general relativity. The Geometrical and physical properties of the model universe are studied comparing with the present day’s observational findings. The model universe obtained here starts with the big bang and as time progresses both particle density ρp and energy density ρ decreases with expansion of our Universe.

Modified Chaplygin gas with viscous fluid in FRW cosmology

Considering the modified viscous Chaplygin gas as the form of dark energy contained in the Universe, we study the interaction of dark energy with other components like electromagnetic field comprising the Universe. It is incidentally found that the interaction effect behaves like the electric charge from an electromagnetic field showing the possibility that a part of the dark energy can be utilized in the form of electrical energy. Further, from studying geometrical and physical behaviors of the evolution of this model Universe, it can be rightly said that this derived model behaves as the actual Universe.

The Radiation-Dominated Universe in Nonstandard Cosmology

We continue the recent study of our model theory of low-density cosmology without dark matter. We assume a purely radiative spherically symmetric background and treat matter as anisotropic perturbations. Einstein’s equations for the background are solved numerically. We find two irregular singular points, one is the Big Bang and the other a Big Crunch. The radiation temperature continues to decrease for another 0.21 Hubble times and then starts to increase towards infinity. Then we derive the four evolution equations for the anisotropic perturbations. In the Regge- Wheeler gauge there are three metric perturbations and a radial velocity perturbation. The solution of these equations allow a detailed discussion of the cosmic evolution of the model universe under study.

Interaction of Bianchi type-I anisotropic cloud string cosmological model universe with electromagnetic field

Here, we have investigated the interaction of Bianchi type-I anisotropic cloud string cosmological model universe with electromagnetic field in the context of general relativity. In this paper, the energy-momentum tensor is assumed to be the sum of the rest energy density and string tension density with an electromagnetic field. To obtain exact solution of Einstein’s field equations, we take the average scale factor as an integrating function of time. Also, the dynamics and significance of various physical parameters of model are discussed.

Space is the Same thing as Energy-The Underlying Structure of the Observed Universe

Energy and Matter is the same thing. Space and Energy is the same thing. Time and change are different. These conclusions give rise to a different view of Atomic and molecular Structure and force. The model universe is a Quantum Universe, Quantum solution for quantum point driven, Time Free, Dimension Free, Thermodynamic Free and therefore entropy free. AuT built this list which is foundational and unique. 1. All dimensions present (at least 5) exist together within the matrix of the universe and in any regional matrix; subgroups of these dimensions are present. • Space has no dimension, precharge exists in a single dimension, prephotons exist in two; neutrons (complete matter) in 3 and blackholes in 4. • The definitions of time and space mean that exchanges of information state (ct state) between space and prephotonsoccur independent of time. Time as we experience arises between the prephoton states and ends with compression to neutrons. 2. All change is quantum change in response to a single variable leading to the universe existing as a series of quantum states or snapshots. Force and time are effects based on this quantum change. 3. Time and change are different. Changes in the single variable lead to time, but time is not required for that underlying change nor does it affect that change. 4. Time is an effect like force and dimension of the quantum change between states some of which occur without time-based reference giving rise to features like wave - particle false duality and the impression of charge among other features. 5. Space is made of the same type of information as all other states (energy, matter, black holes) which are folded from space based on exponential compression/folding. 6. Waves, Photons, Electrons and protons are examples of transitional states (ct3-ct4) between prephotons (ct3) and neutrons (ct4); atoms (after hydrogen) and molecular states through neutron stars are transitional states between neutrons (ct4) and black holes (ct5) along with intervening transitional ct3-ct4 states.

Isotropic Robertson-Walker model universe with dynamical cosmological parameter Λ in Brans-Dicke Theory of Gravitation

This paper discusses about Robertson-Walker space-time with quadratic equation of state and dynamical cosmological parameter Λ . Some exact solutions of Einstein’s field equations for three cases have been obtained. Physical behaviors of the models are discussed in detail.