Space resolved concentrations of helium He (S1) metastable atoms in an atmospheric pressure radio-frequency micro-plasma jet were measured using tunable diode laser absorption spectroscopy. The spatial profile of metastable atoms in the volume between the electrodes was deduced for various electrode gap distances. Density profiles reveal the sheath structure and reflect the plasma excitation di...

Using computer simulations, we study metastability in a two-dimensional Ising ferromagnet relaxing toward a nonequilibrium steady state. The interplay between thermal and nonequilibrium fluctuations induces resonant and scale-invariant phenomena not observed in equilibrium. In particular, we measure noise-enhanced stability of the metastable state in a nonequilibrium environment. The limit of m...

The phase diagram of a system consisting of hard spheres with an attractive Yukawa interaction is computed by Monte Carlo simulations. Upon decreasing the range of attraction, we find the following scenarios: (a) a stable fluid-fluid and fluid-solid transition, a triple point with fluid-fluid-solid coexistence, and a metastable isostructural solid-solid transition (b) a fluid-fluid and isostruc...

We present a novel method for the identification of the most important metastable states of a system with complicated dynamical behavior from time series information. The novel approach represents the effective dynamics of the full system by a Markov jump process between metastable states, and the dynamics within each of these metastable states by rather simple stochastic differential equations...

All nanostructures are metastable--but some are more metastable than others. Here we employ aberration-corrected electron microscopy and atomistic computer simulations to demonstrate the hierarchy of metastability in deposited, size-selected gold nanoparticles (clusters), an archetypal class of nanomaterials well known for the catalytic activity which only appears on the nanometer-scale. We sho...

The authors examine the possibility of a two-step nucleation to the bulk condensation transition that proceeds via a metastable liquid cluster intermediate having some preferred size. The metastable intermediate is stabilized by electrostatic repulsion, which becomes screened by small mobile ions at sufficiently large cluster sizes, thus allowing the eventual condensation to a bulk phase. Our c...

Mean squared displacements and velocity auto correlation functions are calculated using molecular dynamics for hard spheres under a range of conditions (i) for the equilibrium fluid below freezing; (ii) for the metastable fluid above freezing; and (iii) for the hard sphere crystal, both in the metastable region between freezing and melting, and in the stable region above melting. In addition, s...

The ability of environmental factors to shape health and disease involves epigenetic mechanisms that mediate gene-environment interactions. Metastable epiallele genes are variably expressed in genetically identical individuals due to epigenetic modifications established during early development. DNA methylation within metastable epialleles is stochastic due to probabilistic reprogramming of epi...

A “metastable solution” to a differential equation typically refers to a family of solutions for which nearby initial data converges to the family much faster than evolution along the family. Metastable families have been observed both experimentally and numerically in various contexts; they are believed to be particularly relevant for organizing the dynamics of fluid flows. In this work we pro...

We discuss the coupling of heavy moduli fields to light fields when the dynamics of the latter, absent such couplings, yields metastable vacua. We show that the survival of the vacuum structure of the local model depends nontrivially on the cross-couplings of the two sectors. In particular we find that for ”local” models (such as those realized by D-branes in type II string theories) with metas...