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This paper deals with a study of the effects that spherically symmetric first-order metric perturbations and vacuum quantum fluctuations have on the stability of the multiply connected de Sitter spacetime recently proposed by Gott and Li.…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Pedro F. Gonzalez-Diaz

Motivated by stochastic models of climate phenomena, the steady-state of a linear stochastic model with additive Gaussian white noise is studied. Fluctuation theorems for nonequilibrium steady-states provide a constraint on the character of…

Statistical Mechanics · Physics 2008-01-04 Jeffrey B. Weiss

We compute, from first principles, the quantum fluctuations about instanton saddle points of the Euclidean path integral for Einstein gravity coupled to a scalar field. The Euclidean two-point correlator is analytically continued into the…

Astrophysics · Physics 2016-08-25 Steven Gratton , Neil Turok

The first mathematical problems of the global analysis of dynamical models can be traced back to the engineering problem of the Watt governor design. Engineering requirements and corresponding mathematical problems led to the fundamental…

Studies in string theory and in quantum gravity suggest the existence of a finite lower bound to the possible resolution of lengths which, quantum theoretically, takes the form of a minimal uncertainty in positions $\Delta x_0$. A finite…

High Energy Physics - Theory · Physics 2014-11-18 Achim Kempf

We review the orbital stability of the planar circular restricted three-body problem, in the case of massless particles initially located between both massive bodies. We present new estimates of the resonance overlap criterion and the Hill…

Earth and Planetary Astrophysics · Physics 2015-09-16 X. S. Ramos , J. A. Correa-Otto , C. Beaugé

Fluctuations due to a super-position of uncorrelated Lorentzian pulses with a random distribution of amplitudes and duration times are considered. These are demonstrated to be strongly intermittent in the limit of weak pulse overlap,…

Plasma Physics · Physics 2018-03-14 O. E. Garcia , A. Theodorsen

Evidence of small-scale condensations in the magnetic molecular clouds has been accumulating over the past decades through radio and optical/ultraviolet observations. The origin and shape of these small-scale condensations is a disputable…

Astrophysics · Physics 2007-05-23 Mohsen Nejad-Asghar , Jamshid Ghanbari

We study the spontaneous symmetry breaking of O(3) scalar field on a fuzzy sphere $S_F^2$. We find that the fluctuations in the background of topological configurations are finite. This is in contrast to the fluctuations around a uniform…

High Energy Physics - Theory · Physics 2012-04-25 S. Digal , T. R. Govindarajan

We study the active work fluctuations of an active Ornstein-Uhlenbeck particle in the presence of a confining harmonic potential. We tackle the problem analytically both for stationary and generic uncorrelated initial states. Our results…

Statistical Mechanics · Physics 2023-02-27 Massimiliano Semeraro , Giuseppe Gonnella , Antonio Suma , Marco Zamparo

In a shear flow particles migrate to their equilibrium positions in the microchannel. Here we demonstrate theoretically that if particles are inertial, this equilibrium can become unstable due to the Saffman lift force. We derive an…

Fluid Dynamics · Physics 2021-10-04 Evgeny S. Asmolov , Tatiana V. Nizkaya , Jens Harting , Olga I. Vinogradova

The position of an invasion front, propagating into an unstable state, fluctuates because of the shot noise coming from the discreteness of reacting particles and stochastic character of the reactions and diffusion. A recent macroscopic…

Statistical Mechanics · Physics 2015-06-12 Baruch Meerson , Pavel V. Sasorov , Arkady Vilenkin

This paper examines the classical dynamics of false vacuum regions embedded in surrounding regions of true vacuum, in the thin-wall limit. The dynamics of all generally relativistically allowed solutions -- most but not all of which have…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Anthony Aguirre , Matthew C. Johnson

We examine the modulational and parametric instabilities arising in a non-autonomous, discrete nonlinear Schr{\"o}dinger equation setting. The principal motivation for our study stems from the dynamics of Bose-Einstein condensates trapped…

Soft Condensed Matter · Physics 2015-06-24 Z. Rapti , P. G. Kevrekidis , A. Smerzi , A. R. Bishop

This is the second of two articles on the study of a particle system model that exhibits a Turing instability type effect. About the hydrodynamic quations obtained in \cite{CSL17a}, we find conditions under which Turing instability occurs…

Probability · Mathematics 2018-12-26 M. Capanna , N. Soprano-Loto

We develop an alternative approach to this field, which was to a large extent developed by Verbeure et al. It is meant to complement their approach, which is largely based on a non-commutative central limit theorem and coordinate space…

Mathematical Physics · Physics 2009-10-31 Manfred Requardt

Heavy scalar fields can undergo an instability during inflation as a result of their kinetic couplings with the inflaton. This is known as the geometrical destabilization of inflation, as it relies on the effect of the negative curvature of…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Sebastian Garcia-Saenz , Sébastien Renaux-Petel , John Ronayne

Fluctuations and noise may alter the behavior of dynamical systems considerably. For example, oscillations may be sustained by demographic fluctuations in biological systems where a stable fixed point is found in the absence of noise. We…

Adaptation and Self-Organizing Systems · Physics 2009-11-13 Richard P. Boland , Tobias Galla , Alan J. McKane

We develop a framework to give upper bounds on the "practical" computational complexity of stability problems for a wide range of nonlinear continuous and hybrid systems. To do so, we describe stability properties of dynamical systems using…

Systems and Control · Computer Science 2014-06-05 Sicun Gao , Soonho Kong , Edmund Clarke

While the warming trends of the Earth's mean temperature are evident at climatological scales, the local temperature at shorter timescales are highly fluctuating. In this letter we show that the probabilities of such fluctuations are…

Geophysics · Physics 2023-04-21 Jun Yin , Amilcare Porporato , Lamberto Rondoni