We consider the interaction between perturbations in the inflaton and in the metric during the preheating phase in simple inflationary models. By numerically integrating the Einstein field equations we are able to gauge the impact of non-linear gravitational effects on preheating for the first time. In the λφ model we find a large increase in the amplitude of sub-Hubble metric modes, beyond tha...

This paper discusses high-energy-density laboratory astrophysics experiments exploring the RayleighTaylor instability under conditions similar to the blast wave driven, outermost layer in a core-collapse supernova. The planar blast wave is created in an experimental target using the Omega laser. The blast wave crosses an unstable interface with a seed perturbation machined onto it. The perturba...

Extensive experimental and numerical investigations of feedback-induced instabilities in single-mode distributed-feedback lasers are presented that confirm the basic assumptions of the Lang-Kobayashi model. We give experimental evidence of the occurrence of low-frequency fluctuation (LFF), alternation between LFF and stable emission, and coherence collapse during single-mode operation of the la...

We present data from recent high-energy-density laboratory experiments designed to explore the Rayleigh– Taylor instability under conditions relevant to supernovae. The Omega laser is used to create a blast wave structure that is similar to that of the explosion phase of a core-collapse supernova. An unstable interface is shocked and then decelerated by the planar blast wave, producing Rayleigh...

T. Hanawa and T. Matsumoto Stability of Dynamically Collapsing Gas Sphere 1 document page1 Stability of Dynamically Collapsing Gas Sphere Tomoyuki Hanawa Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 E-mail(TH): [email protected] and Tomoaki Matsumoto Faculty of Liberal Arts, Hosei University, Fujimi, Chiyoda-ku, Tokyo 102-8160 E-mail(TH): [email protected]...

OBJECTIVE We tested whether the continuous monitoring of dynamic compliance could become a useful bedside tool for detecting the beginning of collapse of a fully recruited lung. DESIGN Prospective laboratory animal investigation. SETTING Clinical physiology research laboratory, University of Uppsala, Sweden. SUBJECTS Eight pigs submitted to repeated lung lavages. INTERVENTIONS Lung recr...

We present the results from a numerical study of critical gravitational collapse of axisymmetric distributions of massless scalar field energy. We find threshold behavior that can be described by the spherically symmetric critical solution with axisymmetric perturbations. However, we see indications of a growing, nonspherical mode about the spherically symmetric critical solution. The effect of...

Although several studies have investigated the effect of degradation on the behavior of structures, investigations on collapse margin ratios are rare in the literature. In this study, the effect of strength and stiffness degradation on collapse capacity of steel moment frames is investigated. The aim is to determine margin of safety against collapse using a probabilistic approach. For this reas...

The answer may be yes. A discrete model of energy-conserved wavefunction collapse is proposed. It is shown that the model is consistent with existing experiments and our macroscopic experience.