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Related papers: Delayed Keen Model with Inflation

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Using the latest observational data, we constrain the inflationary dynamics and the subsequent reheating epoch. Predictions for both phases can be significantly improved by employing numerically computed results compared to the slow-roll…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Ying-Ying Ye , Bao-Min Gu

We consider small-field models which invoke the usual framework for the effective field theory, and large-field models which go beyond that. Present and future possibilities for discriminating between the models are assessed, on the…

Astrophysics · Physics 2015-06-24 Laila Alabidi , David Lyth

The bifurcation diagram of a model nonlinear Langevin equation with delayed feedback is obtained numerically. We observe both direct and oscillatory bifurcations in different ranges of model parameters. Below threshold, the stationary…

Statistical Mechanics · Physics 2008-10-27 Francoise Lepine , Jorge Vinals

A delayed differential equation modelling a single neuron with inertial term is considered in this paper. Hopf bifurcation is studied by using the normal form theory of retarded functional differential equations. When adopting a…

Chaotic Dynamics · Physics 2007-05-23 Chunguang Li , Guanrong Chen , Xiaofeng Liao , Juebang Yu

Various field and laboratory experiments show that prey refuge plays a significant role in the stability of prey-predator dynamics. On the other hand, theoretical studies show that delayed system exhibits a much more realistic dynamics than…

Dynamical Systems · Mathematics 2016-08-26 Debaldev Jana , R. Gopal , M. Lakshmanan

We study inflationary models where the kinetic sector of the theory has a non-linearly realised symmetry which is broken by the inflationary potential. We distinguish between kinetic symmetries which non-linearly realise an internal or…

High Energy Physics - Theory · Physics 2018-07-04 Remko Klein , Diederik Roest , David Stefanyszyn

A network of noisy bistable elements with global time-delayed couplings is considered. A dichotomous mean field model has recently been developed describing the collective dynamics in such systems with uniform time delays near the…

Statistical Mechanics · Physics 2007-05-23 Daniel Huber , Lev Tsimring

This paper focuses on the delay induced Hopf bifurcation in a dual model of Internet congestion control algorithms which can be modeled as a time-delay system described by a one-order delay differential equation (DDE). By choosing…

Networking and Internet Architecture · Computer Science 2007-12-27 Dawei Ding , Jie Zhu , Xiaoshu Luo , Yuliang Liu

In this work we introduce a differential equation model with time-delay that describes the three-stage dynamics and the two time scales observed in HIV infection. Assuming that the virus has high mutation and rapid reproduction rates that…

Biological Physics · Physics 2015-03-13 Flora S. Bacelar , Roberto F. S. Andrade , Rita M. Zorzenon dos Santos

We propose a paradigmatic model system, a subcritical Hopf normal form subjected to noise and time-delayed feedback, to investigate the impact of time delay on coherence resonance in non-excitable systems. We develop analytical tools to…

Adaptation and Self-Organizing Systems · Physics 2014-12-08 Paul M. Geffert , Anna Zakharova , Andrea Vüllings , Wolfram Just , Eckehard Schöll

We consider a neural field model which consists of a network of an arbitrary number of Wilson-Cowan nodes with homeostatic adjustment of the inhibitory coupling strength and time delayed, excitatory coupling. We extend previous work on this…

Dynamical Systems · Mathematics 2023-11-28 Isam Al-Darabsah , Sue Ann Campbell , Bootan Rahman

The present paper addresses the swing equation with additional delayed damping as an example for pendulum-like systems. In this context, it is proved that recurring sub- and supercritical Hopf bifurcations occur if time delay is increased.…

Dynamical Systems · Mathematics 2019-12-23 Tessina H. Scholl , Lutz Gröll , Veit Hagenmeyer

Inflation models can have an early phase of inflation where the evolution of the inflaton is driven by quantum fluctuations before entering the phase driven by the slope of the scalar field potential. For a Coleman-Weinberg potential this…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-06 Arjun Berera , Raghavan Rangarajan

We review the main aspects of the warm inflation scenario, focusing on the inflationary dynamics and the predictions related to the primordial spectrum of perturbations, to be compared with the recent cosmological observations. We study in…

High Energy Physics - Phenomenology · Physics 2010-04-21 Mar Bastero-Gil , Arjun Berera

The celebrated Mackey-Glass model describes the dynamics of physiological \textit{delayed} systems in which the actual evolution depends on the values of the variables at some \textit{previous} times. This kind of systems are usually…

Chaotic Dynamics · Physics 2014-08-22 Pablo Amil , Cecilia Cabeza , Arturo C. Martí

Neural field models with transmission delay may be cast as abstract delay differential equations (DDE). The theory of dual semigroups (also called sun-star calculus) provides a natural framework for the analysis of a broad class of delay…

Dynamical Systems · Mathematics 2017-12-11 Stephan A. van Gils , Sebastiaan G. Janssens , Yuri A. Kuznetsov , Sid Visser

In this research, we have derived a mathematical model for within human dynamics of COVID-19 infection using delay differential equations. The new model considers a 'latent period' and 'the time for immune response' as delay parameters,…

Populations and Evolution · Quantitative Biology 2025-01-14 Amar N. Chatterjee , Teklebirhan Abraha , Fahad Al Basir , Delfim F. M. Torres

We derive an alternative expression for a delayed logistic equation in which the rate of change in the population involves a growth rate that depends on the population density during an earlier time period. In our formulation, the delay in…

Dynamical Systems · Mathematics 2022-06-07 Chiu-Ju Lin , Ting-Hao Hsu , Gail S. K. Wolkowicz

Using the model of a generalized Van der Pol oscillator in the regime of subcritical Hopf bifurcation we investigate the influence of time delay on noise-induced oscillations. It is shown that for appropriate choices of time delay either…

Chaotic Dynamics · Physics 2015-06-23 V. Semenov , A. Feoktistov , T. Vadivasova , E. Schöll , A. Zakharova

In the framework of a flat FLRW model we derive an inflationary regime in which the scalar field, laying on the plateau of its potential, admits a linear time dependence and remains close to a constant value. The behaviour of inhomogeneous…

General Relativity and Quantum Cosmology · Physics 2016-11-09 Giovanni Imponente , Giovanni Montani