Dynamic Instability Criterion for Circular String Loops

Instability criterion for oblique modes in stratified circular Couette flow

An analytical approach is carried out that provides an inviscid stability criterion for the strato-rotational instability (in short SRI) occurring in a Taylor-Couette system. The control parameters of the problem are the rotation ratio μ and the radius ratio η. The study is motivated by recent experimental [1] and numerical [2, 3] results reporting the existence of unstable modes beyond the Ray...

Avoidance of Collapse by Circular Current-carrying Cosmic String Loops

Brandon CARTER, Patrick PETER and Alejandro GANGUI Département d’Astrophysique Relativiste et de Cosmologie, Observatoire de Paris-Meudon, UPR 176, CNRS, 92195 Meudon (France), 2 International Center for Theoretical Physics, P. O. Box 586, 34100 Trieste, Italy, 3 International School for Advanced Studies, Via Beirut 4, 34014 Trieste, Italy. Email: [email protected], [email protected], gangu...

Criterion for flow liquefaction instability

This study describes a general liquefaction flow instability criterion for elastoplastic soils based on the concept of loss of uniqueness. We apply the criterion to the general case of axisymmetric loading and invoke the concepts of effective stresses and loss of controllability to arrive at a general criterion for the onset of liquefaction flow. The criterion is used in conjunction with an ela...

Reionization from cosmic string loops

Abstract Loops formed from a cosmic string network at early times would act as seeds for early formation of halos, which would form galaxies and lead to early reionization. With reasonable guesses about astrophysical and string parameters, the cosmic string scale Gμ must be no more than about 3 × 10 to avoid conflict with the reionization redshift found by WMAP. The bound is much stronger for s...

A Criterion for Nuclear-Energized Pulsational Instability