Open questions are still present in fundamental Physics and Cosmology, like the nature of Dark Matter, the matter-antimatter asymmetry and the validity of the particle

Random packing of surfaceless starlike particles built of 3 to 50 line segments was studied using random sequential adsorption algorithm. Numerical simulations allow us to determine saturated packing densities as well as the first two virial expansion coefficients for such objects. Measured kinetics of the packing growth supports the power law known to be valid for particles with a finite surface; however, the dependence of the exponent in this law on the number of star arms is unexpected. The density autocorrelation function shows fast superexponential decay as for disks, but the typical distance between closest stars is much smaller than between disks of the similar size, especially for a small number of arms.

Two-dimensional ensembles of bent-core shaped molecules attain at highly orienting surfaces liquid crystalline structures characteristic mostly for lamellar chiral or nonchiral antiferroelectric order. Here, using the Onsager-type of density functional theory supplemented by constant-pressure Monte-Carlo (MC) simulation we investigate the role of excluded-volume interactions in stabilizing different structures in monolayers filled with bent-shaped molecules. We study influence of molecular features, like the apex angle, thickness of the arm and the type of the arm edges on the stability of layered structures. For simple molecular shapes taken the observed phases are dominated by the lamellar antiferroelectric type as observed experimentally, but a considerable sensitivity of the ordering to details of the molecular shape is found for order parameters and wave vectors of the structures. Interestingly, for large opening angles and not too thick molecules a window of stable nematic splay-bend phase is shown to exist. The presented theory models equilibrium properties of bent-core liquid crystals subjected to strong planar anchoring, in the case when details of the surface are of secondary importance.

Thermodynamics of the ideal Fermi gas trapped in an external generic power law potential U =ai | ni is investigated systematically from the grand thermodynamic potential in d-dimensional space. These properties are explored carefully in the degenerate limit (µ K B T ), where the thermodynamic properties are greatly dominated by the Pauli exclusion principle. Pressure and energy along with the isothermal compressibility are nonzero at T = 0K. The nonzero value of compressibility implies that zero point pressure is not a constant but depends on volume.

The calculations of the dimensionless layer monomer density profiles for a dilute solution of phantom ideal ring polymer chains and star polymers with f = 4 arms in a Θ-solvent confined in a slit geometry of two parallel walls with repulsive surfaces and for the mixed case of one repulsive and the other inert surface were performed. Furthermore, taking into account the Derjaguin approximation, the dimensionless layer monomer density profiles for phantom ideal ring polymer chains and star polymers immersed in a solution of big colloidal particles with different adsorbing or repelling properties with respect to polymers were calculated. The density-force relation for the above-mentioned cases was analyzed, and the universal amplitude ratio B was obtained. Taking into account the small sphere expansion allowed obtaining the monomer density profiles for a dilute solution of phantom ideal ring polymers immersed in a solution of small spherical particles, or nanoparticles of finite size, which are much smaller than the polymer size and the other characteristic mesoscopic length of the system. We performed molecular dynamics simulations of a dilute solution of linear, ring, and star-shaped polymers with N = 300, 300 (360), and 1201 (4 × 300 + 1-star polymer with four arms) beads accordingly. The obtained analytical and numerical results for phantom ring and star polymers are compared with the results for linear polymer chains in confined geometries.

Influence of confinement on a two-dimensional Lennard-Jones system of spherical particles has been studied by means of Molecular Dynamics simulations. High Resolution Density Map (HRDM) method has been applied to study of inhomogeneous configurations in a circular geometry. Solidification has been shown to depend strongly as well on the structure as on the type of constituting particles of the surrounding wall. Within the liquid state, for certain parameters of density and temperature, configurations occur that remind of the structure of node lines characteristic for the Bessel equation, which are argued to play the role of the seeds for solidification.

In the present paper, we report a molecular dynamics simulation of two-dimensional Lennard-Jones system with a simple square start configuration. Mean square displacement was computed showing interesting dependence on high pressure conditions in short time scale, corresponding to an abrupt restructurization. This paper is the first to report the qualitative and quantitative details of this phenomenon.

The authors wish to make the following correction to this paper [...]