بررسي ترموديناميك و گذارهاي فاز سياهچاله ها در حضور ثابت كيهانشناسي متغير

چكيده انگليسي :

abstractIn this thesis we focused on explaining the critical behaviour and phase transition in black holes withthe variation of cosmological constant The simplest choice is Schwarzschild black hole which is lo cally thermodynamically unstable In the precense of charge and angular momentum there is a phasetransition from unstable to stable branch in the system of black holes So the thermodynamics quan tities such as charge and angular momentum make the system more stable Also there is a phasetransition from unstable to stable phase in Schwarzschild Anti de Sitter AdS black hole with thecosmological constant as thermodynamic pressure We consider the critical behaviour and phasetransition of charged black hole Reissner Nordstrom and rotating black hole Kerr in AdS spacetime A conjugate quantity to the thermodynamic pressure is the thermodynamic volume which canformally be obtained from the first law of black hole thermodynamics In this condition the criticalbehaviour and critical exponent Reissner Nordstrom AdS and Kerr AdS are similar to Van der Waalsfluid We specifically study the thermodynamics of higher dimensional rotating asymptotically flatand AdS black holes with the cosmological constant as thermodynamic pressure We plot the asso ciated thermodynamic potential the Gibbs free energy and study its behaviour to uncover possiblethermodynamic phase transitions for both cases of single and multiply rotating parameter The re sults show that the single spinning Kerr AdS has a reentrant phase transitions of multicomponentliquids and multiply rotating Kerr AdS black holes exhibit a rich set of interesting thermodynamicphenomena analogous to the every day thermodynamics of simple substances multiple first ordersolid liquid gas phase transitions of the Van der Waals type Furthermore critical behaviour and phasetransition of hairy black holes in massive gravity and black holes in higher order gravities are con sidered We study Gauss Bonnet Born Infeld AdS black holes GB BI AdS and Born Infeld AdS BI AdS black holes in the third order of Lovelock gravity We find reentrant and triple point phasetransitions RPT TP and also multiple reentrant phase transitions multiple RPT as the pressureof the system increased Also the critical behaviour and phase transition of Myers Perry black holeswith equal angular momenta by including the corrections beyond the semiclassical approximationon Hawking temperature in the grand canonical ensemble are investigated There are several differ ent methods for calculating the corrections to the semiclassical Bekenstein Hawking entropy Theseare based on statistical mechanical arguments field theory methods quantum geometry the Cardyformula the generalized uncertainty principle etc Finaly the future singularities of the universe byusing the Friedmann equations with the effect of both the Entropic force and running gravitational cou pling is calculated The effect of entropic force changes the pressure and energy density behavioursat singularity time in the singularity type II But running gravitational coupling as function of energydensity of the universe changes time evolution of the universe

شركت قناد، زينب

بررسي ترموديناميك و گذارهاي فاز سياهچاله ها در حضور ثابت كيهانشناسي متغير