Browsing by Author "LHR TP 6477"

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    Cosmic Thermodynamics of Matter Creation Models in Alternative Theories of Gravity
    (LHR TP 6477, 2020) Farzan Mushtaq; SP19-RMT-021; LHR TP 6477; Dr. Shamaila Rani
    This thesis is devoted to study some cosmological models in the scenar- ios of two gravitational theories like fractal universe model and dynamical Chern-Simons modi¯ed theory in particle creation mechanism. In the case of fractal universe model, we consider particle creation rate as constant and variable with two models. We use Gibbs equation to ¯nd out pressure of particle creation rate adiabatic matter phenomenon. For these cases, cosmological parameters like e®ective equation of state and deceleration parameter are studied. Also, we investigate the behavior of generalized sec- ond law of thermodynamics for Barrow entropy by taking constant particle creation rate. For dynamical Chern-Simons theory, two variable particle creation rate models are used for which we explore e®ective equation of state parameter and deceleration parameter.
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    Generalized Chaplygin Gas Traversable Wormhole Solutions by Using GUP Corrected Casimir Energy
    (Library Information Services, COMSATS University Islamabad, Lahore Campus, 2020) Ubaid Ur Rehman; SP19-RMT-019; LHR TP 6477; Dr. Abdul Jawad
    In this thesis, we explore the wormhole solutions (which are initially pro- sed by Garattoni (Eur. Phys. J. C 79(2019)951) who take generalized certainty principle (GUP) with Casimir energy) in the framework of two ll-known dark energy models, generalized Chaplygin gas and polytropic s. We consider the GUP corrected pressure (force per unit surface area) the equation of state of these dark energy models to construct the gener- zed Chaplygin gas corrected energy density and polytropic gas corrected ergy density. Three models of redshift function are taken into account construct shape function as well as wormhole geometry for both cases corrected energy densities. We find the behavior of some parameters ough equation of state, energy conditions (null, weak and strong) at the oat of the wormhole with radius r0.