We apply a parameterization-independent approach to fitting the dark energy equation-of-state (EOS). Utilizing the latest type Ia supernova data, combined with results from the cosmic microwave background and baryon acoustic oscillations, we find that the dark energy is consistent with a cosmological constant. We establish independent estimates of the evolution of the dark energy EOS by diagona...

The equation of state (EOS) of a Fermi superfluid is investigated in the BCS-BEC crossover at zero temperature. We discuss the EOS based on Monte-Carlo (MC) data and asymptotic expansions and the EOS derived from the extended BCS (EBCS) mean-field theory. Then we introduce a time-dependent density functional, based on the bulk EOS and Landau’s superfluid hydrodynamics with a von Weizsäcker-type...

We constructed several sequences of classical Cepheid envelope models at solar chemical composition (Y = 0.28, Z = 0.02) to investigate the dependence of the pulsation properties predicted by linear and nonlinear hydrodynamical models on input physics. To study the dependence on the equation of state (EOS) we performed several numerical experiments by using the simplified analytical EOS origina...

Polymer-RISM theory is applied to study athermal polymeric lattice fluids. The intermolecular segmental distributions and the compressibility equation of state (EoS) have been obtained within the approach for three different intramolecular distribution functions, i.e., the random flight, the non reversal random walk, and an intramolecular distribution obtained from Monte Carlo simulations. Both...

A two parameters equation of state (EOS) for nonaqueous electrolyte solutions system has been developed. The equation is in terms of Helmholtz free energy and incorporated with results of low density expansion of non-primitive mean spherical approximation. The EOS was tested for experimental data reported in literatures of 9 nonaqueous single electrolyte solutions of which the temperature was 2...

We study the equation of state (EOS) of quark matter at zero temperature, using the Color Dielectric Model (CDM) to describe confinement. Sensible results are obtained in the version of the CDM for which confinement is imposed smoothly. The two–phases version of the model turns out to give unrealistic results for the EOS. Chiral symmetry plays a marginal rôle and the quarks are massive till hig...

An extended Peng-Robinson equation of state (EPR-EOS) is used to model the vapor-liquid equilibrium (VLE) in systems containing (water + NaCl + CO2), (water + methanol + NaCl + CO2), (water + Na2SO4 + CO2) and (water + NH4Cl + CO2). The binary and ternary interaction parameters between salt and solvent are adjusted...

A PDAE model of a multicomponent gas pipeline has been formulated and solved using the ode15s solver of Matlab. The model with boundary conditions allows for reactions and di usion. Also, general cubic equations of state for pressure and enthalpy are described. To simplify the implementation at this stage, a non-reactive, non-di usional model with fixed feed composition is considered, and multi...

Using density functional molecular dynamics simulations, we determine the equation of state for hydrogen-helium mixtures spanning density-temperature conditions typical of giant planet interiors, ∼ 0.2−9 g cm−3 and 1000−80 000 K for a typical helium mass fraction of 0.245. In addition to computing internal energy and pressure, we determine the entropy using an ab initio thermodynamic integratio...

Probing Equation of State (EoS) of QCD matter in relativistic heavy-ion collisions is still a fascinating problem inspiring new experimental projects [1]. Hydrodynamic models have an advantage that they directly address EoS of hot and dense nuclear matter, which is of prime interest for this domain of physics. We have developed 3D 3fluid relativistic hydrodynamic model [2, 3] for simulating hea...