4 research outputs found
The classical and quantum implications of the Raychaudhuri Equation in f(T)-gravity
The present work deals with the classical and quantum aspects of the
Raychaudhuri equation in the framework of f(T)-gravity theory. In the
background of homogeneous and isotropic Friedmann Lemaitre Robertson Walker
space time, the Raychaudhuri equation has been formulated and used to examine
the focusing theorem and convergence condition for different choices of f(T).
Finally in quantum cosmology, the wave function of the universe has been shown
to be the energy eigen function of the time independent Schrodinger equation of
a particle. Also probability measure on the mini-super space has been examined
at zero volume for singularity analysis in the quantum regime. Lastly the
Bohmian trajectory for the present quantum system has been explicitly
determined for some particular choices.Comment: 22 pages 18 figure
Raychaudhuri equation and Bouncing cosmology
The present work deals with an exhaustive study of bouncing cosmology in the
background of homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker
space-time. The geometry of the bouncing point has been studied extensively and
used as a tool to classify the models from the point of view of cosmology.
Raychaudhuri equation (RE) has been furnished in these models to classify the
bouncing point as regular point or singular point. Behavior of time-like
geodesic congruence in the neighbourhood of the bouncing point has been
discussed using the Focusing Theorem which follows as a consequence of the RE.
An analogy of the RE with the evolution equation for a linear harmonic
oscillator has been made and an oscillatory bouncing model has been discussed
in this context.Comment: 15 pages, 9 figure
Raychaudhuri Equation from Lagrangian and Hamiltonian formulation : A Quantum Aspect
The paper deals with a suitable transformation related to the metric scalar
of the hyper-surface so that the Raychaudhuri Equation (RE) can be written as a
second order nonlinear differential equation. A first integral of this second
order differential equation gives a possible analytic solution of the RE. Also,
it is shown that construction of a Lagrangian (and hence a Hamiltonian) is
possible, from which the RE can be derived. Wheeler-Dewitt equation has been
formulated in canonical quantization scheme and norm of it's solution (wave
function of the universe) is shown to affect the singularity analysis in the
quantum regime for any spatially homogeneous and isotropic cosmology. Finally
Bohmian trajectories are formulated with causal interpretation and these
quantum trajectories unlike classical geodesics obliterate the initial big-bang
singularity when the quantum potential is included
Theoretical and observational prescription of warm-inflation in FLRW universe with torsion
Abstract The paper deals with Warm Inflationary scenario in FLRW with torsion both from theoretical and observational point of view. In the background of flat FLRW model the Hubble parameter is found to be proportional to the torsion function and warm inflation is examined both in weak and strong dissipation regimes for the power law choice of potential using slow-roll approximation with quasi-stable criteria for radiation. The slow-roll parameters, no.of e-folds, scalar spectral index, and tensor-to-scalar ratio are determined in the present model for mainly three choices of the dissipation coefficient Γ using the Planck data set. Finally, we focus on single-field chaotic quartic potential with the above choices of the dissipation coefficient to confront the warm inflation observational predictions directly with the latest observational data set