We study, using molecular dynamics techniques, how boundary conditions affect the process of fragmentation of finite, highly excited, Lennard-Jones systems. We analyze the behavior of the caloric curves (CC), the associated thermal response functions (TRF) and cluster mass distributions for constrained and unconstrained hot drops. It is shown that the resulting CC's for the constrained case dif...

Molecular docking is a computational chemistry method which has become essential for the rational drug design process. In this context, it has had great impact as a successful tool for the study of ligand-receptor interaction modes, and for the exploration of large chemical datasets through virtual screening experiments. Despite their unquestionable merits, docking methods are not reliable for ...

We review topics of current interest in the physics of electronic, atomic and molecular scattering in the vicinity of thresholds. Starting from phase space arguments, we discuss the modifications of the Wigner law that are required to deal with scattering by Coulomb, dipolar and dispersion potentials, as well as aspects of threshold behaviour observed in ultracold atomic collisions. We employ t...

In the past few decades, advancements in atom cooling technology have allowed for the study of atoms and molecules at very low nanoKelvin temperatures. These experiments have demonstrated a high level of control over individual quantum states and have been useful in studying fundamental aspects of quantum mechanics. Ultracold atoms have proven to be especially valuable for studying interacting ...

Entangled polymer melts exhibit a variety of flow instabilities that limit production rates in industrial applications. We present both experimental and computational findings, using flow of monodisperse linear polystyrenes in a contraction-expansion geometry, which illustrate the formation and development of one such flow instability. This viscoelastic disturbance is observed at the slit outle...

In this essay I analyze Einstein’s statistical papers from 1902–1904. In these papers, Einstein developed the foundations of a theoretical program that he applied to concrete problems in 1905 and in subsequent years. It combined skepticism about classical mechanics, a firm belief in molecules, and absolute confidence in statistical principles. However, Einstein’s dissertation does not follow hi...

The primary purpose of this proposal is to explore the physics of multi-component condensates containing both atomic and molecular species. The adiabatic condition, which sets the limit to the powers and the widths of the laser pulses for an efficient STIRAP, is studied in connection with the collective excitation modes of the CPT state. The resonant Fermi model in which atoms of two opposite s...

In the past, it was a great triumph of Dirac’s theory to predict the fine structure in the energy levels of the simplest atom. Nevertheless, even the relativistic Dirac theory did not completely describe the spectrum of the electron in an H-atom. However, at that time, attempts to obtain accurate information through a study of the Balmer lines have been frustrated by the large Doppler width in ...

techniques has opened a new window on diverse problems in physics. Our focus, in this article, is on a set of issues pertaining to the behavior of fluids, at low Reynolds numbers, for which the inertial forces are tiny compared to viscous forces. We shall discuss classes of long-standing problems for which a computational approach yields qualitatively new information that is inaccessible using ...

The threshold region of the double-photoionization cross section is of particular interest because both ejected electrons move slowly in the Coulomb field of the residual ion. Near threshold both electrons have time to interact with each other and with the residual ion. Also, different theoretical models compete to describe the double-photoionization cross section in the threshold region. We ha...