Cosmological consequences of modified Friedmann equations according to holographic equipartition law

We examine thermodynamically an extra driving term for the flat universe by applying Sharma Mittal entropy to Padmanabhan’s holographic equipartition law. Deviations from the Bekenstein–Hawking entropy by using this law, we generate an extra driving in the acceleration equation. By using the constant and parametrized equation of state parameter, we investigate the different cosmological parameters like deceleration parameter, squared speed of sound, Om-diagnostic and statefinder parameter through graphical approach. We observe compatible results with current observational data in both models. Generalized second law of thermodynamics also remains valid in both cases.

Thermal features of Barrow corrected-entropy black hole formulation

Through the last years, it was demonstrated that quantum corrections of entropy, represented by logarithmic and power law corrections terms, constituted an association between semi-classical entropic areas and the curvature correction in Einstein–Hilbert’s Lagrangian and vice-versa. Loop quantum gravity approach provided the logarithmic corrections, which arises from quantum and thermal equilibrium fluctuations. On the other hand, Barrow’s entropy was introduced from the fact that the black hole surface can be modified due to quantum gravitational effects. The new exponent $$\Delta $$Δ that appears in Barrow’s entropy is a measure of this perturbation. In this letter we have analyzed the thermodynamical effects of the quantum fluctuations upon the geometry of a Barrow’s black hole. We demonstrated that new formulations of the equipartition law, which corresponds to the horizon energy, can be constructed from both entropic formalisms. Besides, we have calculated the heat capacity for both formulations and we discussed their thermal viability. We have also establish a condition on one of the constant pre-factors of the logarithmic correction.

Thermodynamic Prescription of Cosmological Constant in the Randall-Sundrum II Brane

In this work, we apply the quantum corrected entropy function derived from the Generalized Uncertainty Principle (GUP) to the holographic equipartition law to study the cosmological scenario in the Randall-Sundrum (RS) II brane. An extra driving term has come up in the effective Friedmann equation for a homogeneous, isotropic, and spatially flat universe. Further, thermodynamic prescription of the universe constraints this term eventually with an order equivalent to that of the cosmological constant.

Modified Hawking temperature and entropic force: A prescription in FRW model

The idea of Verlinde that gravity is an entropic force caused by information changes associated with the positions of material bodies, is used in the present work for the Friedmann–Robertson–Walker (FRW) model of the Universe. Using modified Hawking temperature, the Friedmann equations are derived on any horizon. For the validity of the first law of thermodynamics (i.e. Clausius relation) it is found that there is modification of Bekenstein entropy on the horizon. However, using equipartition law of energy, Bekenstein entropy is recovered.

Calculation of Thermodynamic and Thermoelastic Properties for Ductile B2-YAg Intermetallics with Molecular Dynamics

The thermodynamic and thermo-elastic properties of ductile intermetallic compounds YAg with B2 structure are investigate with molecular dynamics. The thermodynamic properties at various temperatures, such as lattice parameter, cohesive energy, enthalpy of formation, heat capacity, vibrational entropy and vibrational free energy are computed. The present calculated results show good agreements with available experimental and previous calculated data. At high temperature, the heat capacity tends to a constant with obeys the classical equipartition law. At 300K, the heat capacity of YAg is 23.91 J mol-1 K-1. And those data enrich thermodynamic data-base for YAg. At the whole range 0-600K, the elastic constants follow a normal behavior with temperature that those decrease with increasing temperature, and satisfy the stability conditions for YAg compound. The Cauchy pressure and B/G for YAg increase with elevating temperature. Our results mean that increasing temperature may improve ductility of YAg.