Lowest Order Constrained Variational Calculation of Structure Properties of Protoneutron Star

We calculate the structure properties of protoneutron star such as equation of state, maximum mass, radius and temperature profile using the lowest order constrained variational method. We show that the mass and radius of protoneutron star decrease by decreasing both entropy and temperature. For the protoneutron star, it is shown that the temperature is nearly constant in the core and drops rapidly near the crust.Comment: 14 pages, 12 figures. Int. J. Theor. Phys. (2008) in pres

Finite temperature calculations for the bulk properties of strange star using a many-body approach

We have considered a hot strange star matter, just after the collapse of a supernova, as a composition of strange, up and down quarks to calculate the bulk properties of this system at finite temperature with the density dependent bag constant. To parameterize the density dependent bag constant, we use our results for the lowest order constrained variational (LOCV) calculations of asymmetric nuclear matter. Our calculations for the structure properties of the strange star at different temperatures indicate that its maximum mass decreases by increasing the temperature. We have also compared our results with those of a fixed value of the bag constant. It can be seen that the density dependent bag constant leads to higher values of the maximum mass and radius for the strange star.Comment: 21 pages, 2 tables, 12 figures Astrophys. (2011) accepte

Spin Polarized Asymmetric Nuclear Matter and Neutron Star Matter Within the Lowest Order Constrained Variational Method

In this paper, we calculate properties of the spin polarized asymmetrical nuclear matter and neutron star matter, using the lowest order constrained variational (LOCV) method with the $AV_{18}$, $Reid93$, $UV_{14}$ and $AV_{14}$ potentials. According to our results, the spontaneous phase transition to a ferromagnetic state in the asymmetrical nuclear matter as well as neutron star matter do not occur.Comment: 21 pages, 11 figure

Lowest Order Constrained Variational calculation for Polarized Liquid 3He at Finite Temperature

We have investigated some of the thermodynamic properties of spin polarized liquid $^3\mathrm{He}$ at finite temperature using the lowest order constrained variational method. For this system, the free energy, entropy and pressure are calculated for different values of the density, temperature and polarization. We have also presented the dependence of specific heat, saturation density and incompressibility on the temperature and polarization.Comment: 17 pages, 7 figures. Int. J. Mod. Phys. B 27 (2008) in pres

Interaction of β-Lactoglobulin with Resveratrol: Molecular Docking and Molecular Dynamics Simulation Studies

In this work, the interaction of trans-resveratrol, as a natural polyphenolic compound, and Bovine β-lactoglobulin (BLG), was studied using molecular docking and molecular dynamics simulation methods. The molecular dynamics study makes an important contribution to understanding the effect of the binding of resveratrol on conformational changes of BLG and the stability of a protein-drug complex system in aqueous solution. Molecular docking studies revealed that the resveratrol was bound to the surface of the protein by two hydrogen bond interactions. The binding constant and free energy change, ΔG°, for the binding of resveratrol to BLG were about 6.6 × 105 mol L–1 and –33.4 kJ mol–1, respectively. Furthermore, the results of molecular dynamics simulation represented that the rmsd of unliganded BLG and BLG-resveratrol complex reached equilibration and oscillated around the average value after 600 ps simulation time. The study of the radius of gyration (Rg) revealed that BLG and BLG-resveratrol complexes were stabilized around 1500 ps and also exhibited no conformational change. Finally, analyzing the rms fluctuations suggested that the structure of the ligand binding site remains approximately rigid during the simulation

Lowest Order Constrained Variational Calculation of the Polarized Nuclear Matter with the Modern AV18AV_{18} Potential

The lowest order constrained variational method is applied to calculate the polarized symmetrical nuclear matter properties with the modern $AV_{18}$ potential performing microscopic calculations. Results based on the consideration of magnetic properties show no sign of phase transition to a ferromagnetic phase.Comment: 19 pages, 6 figure

Effect of massive graviton on dark energy star structure

The presence of massive gravitons in the field of massive gravity is considered as an important factor in investigating the structure of compact objects. Hence, we are encouraged to study the dark energy star structure in the Vegh's massive gravity. We consider that the equation of state governing the inner spacetime of the star is the extended Chaplygin gas, and then using this equation of state, we numerically solve the Tolman-Oppenheimer-Volkoff (TOV) equation in massive gravity. In the following, assuming different values of free parameters defined in massive gravity, we calculate the properties of dark energy star such as radial pressure, transverse pressure, anisotropy parameter, and other characteristics. Then, after obtaining the maximum mass and its corresponding radius, we compute redshift and compactness. The obtained results show that for this model of dark energy star, the maximum mass and its corresponding radius depend on the massive gravity's free parameters and anisotropy parameter. These results are consistent with the observational data, and cover the lower mass gap. We also demonstrate that all energy conditions are satisfied for this model, and in the presence of anisotropy, the dark energy star is potentially unstable.Comment: 17 pages, 10 figures, 4 table