Search results for "dynamical system"
showing 10 items of 523 documents
Noise delayed decay of unstable states: theory versus numerical simulations
2004
We study the noise delayed decay of unstable nonequilibrium states in nonlinear dynamical systems within the framework of the overdamped Brownian motion model. We give the exact expressions for the decay times of unstable states for polynomial potential profiles and obtain nonmonotonic behavior of the decay times as a function of the noise intensity for the unstable nonequilibrium states. The analytical results are compared with numerical simulations.
Oscillatory Solutions of Boundary Value Problems
2016
We consider boundary value problems of the form $$\displaystyle\begin{array}{rcl} & x'' = f(t,x,x'), & {}\\ & x(a) = A,\quad x(b) = B,& {}\\ \end{array}$$ assuming that f is continuous together with f x and fx′. We study also equations in a quasi-linear form $$\displaystyle{x'' + p(t)x' + q(t)x = F(t,x,x').}$$ Introducing types of solutions of boundary value problems as an oscillatory type of the respective equation of variations, we show that for a solution of definite type, the problem can be reformulated in a quasi-linear form. Resonant problems are considered separately. Any resonant problem that has no solutions of indefinite type is in fact nonresonant. The ways of how to detect solut…
Reply to "Comment on 'Systematics of radial and angular-momentum Regge trajectories of light non-strange qqbar-states' "
2013
In his Comment, D. Bugg argues against our usage of the PDG collection of light non-strange states together with the half-width rule to analyze the linearity of radial and angular-moment Regge trajectories in the large-N_c limit. After taking into account his observations on our choice of data, the radial Regge trajectories are again analyzed. We still find that our conclusion on the lack of universality between radial- and angular-momentum Regge trajectories is valid.
Theoretical overview on tau physics
2006
8 páginas, 2 figuras, 1 tabla.-- PACS numbers: 14.60.Fg, 13.30.Ce, 12.20.Fv.-- Comunicación presentada a la International Workshop on Tau-Charm Physics (Charm2006), celebrada del 5 al 7 de Junio de 2006 en Beijing (China).-- arXiv:hep-ph/0609138v1
Holographic encoding of universality in corner spectra
2017
In numerical simulations of classical and quantum lattice systems, 2d corner transfer matrices (CTMs) and 3d corner tensors (CTs) are a useful tool to compute approximate contractions of infinite-size tensor networks. In this paper we show how the numerical CTMs and CTs can be used, {\it additionally\/}, to extract universal information from their spectra. We provide examples of this for classical and quantum systems, in 1d, 2d and 3d. Our results provide, in particular, practical evidence for a wide variety of models of the correspondence between $d$-dimensional quantum and $(d+1)$-dimensional classical spin systems. We show also how corner properties can be used to pinpoint quantum phase …
Weak decays, quark mixing and CP violation: Theory overview
1997
10 páginas, 5 figuras, 3 tablas.-- Comunicación presentada al XVI Workshop on Weak Interactions and Neutrinos (WIN'97) celebrado en Junio de 1997 en Capri (Italia).-- arXiv:hep-ph/9709441v1
On the Multifractal Character of the Lorenz Attractor
1992
A detailed analysis of the Lorenz attractor in connection with generalized dimensions is presented in this work. Different methods have been employed to estimate these dimensions. Two of them are of standard type. A new method, based on the minimal spanning tree of the point distribution, is extensively tested in this work. It turns out that the Lorenz attractor is very appropriate for being analyzed through this technique, which produces a very clean estimate of the extrema scaling indices α min and α max . The different methods give qualitatively the same result: The Lorenz attractor has a multifractal character
Universality in disordered systems: The case of the three-dimensional random-bond Ising model
2010
We study the critical behavior of the $d=3$ Ising model with bond randomness through extensive Monte Carlo simulations and finite-size scaling techniques. Our results indicate that the critical behavior of the random-bond model is governed by the same universality class as the site- and bond-diluted models, clearly distinct from that of the pure model, thus providing a complete set of universality in disordered systems.
Group Foundations of Quantum and Classical Dynamics : Towards a Globalization and Classification of Some of Their Structures
1987
This paper is devoted to a constructiveand critical analysis of the structure of certain dynamical systems from a group manifold point of view recently developed. This approach is especially suitable for discussing the structure of the quantum theory, the classical limit, the Hamilton-Jacobi theory and other problems such as the definition and globalization of the Poincare-Cartan form which appears in the variational approach to higher order dynamical systems. At the same time, i t opens a way for the classification of all hamiltonian and lagrangian systems associated with suitably defined dynamical groups. Both classical and quantum dynamics are discussed, and examples of all the different…
Tricritical universality in a two-dimensional spin fluid
1995
Monte Carlo simulations are used to investigate the tricritical point properties of a 2d spin fluid. Measurements of the scaling operator distributions are employed in conjunction with a finite-size scaling analysis to locate the tricritical point and determine the directions of the relevant scaling fields and their associated tricritical exponents. The scaling operator distributions and exponents are shown to match quantitatively those of the 2d Blume-Capel model, confirming that both models belong to the same universality class. Mean-field calculations of the tricritical point properties are also compared with the simulation measurements.