The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Sergej Flach - One of the best experts on this subject based on the ideXlab platform.
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Dynamical glass in weakly nonintegrable Klein-Gordon chains
Physical Review E, 2019Co-Authors: Carlo Danieli, David K. Campbell, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a nonintegrable perturbation creates a Coupling Network in action space which can be short or long ranged. We analyze the dynamics of observables which become the conserved actions in the integrable limit. We compute distributions of their finite time averages and obtain the ergodization time scale ${T}_{E}$ on which these distributions converge to $\ensuremath{\delta}$ distributions. We relate ${T}_{E}$ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations ${\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+}$ dominating the means ${\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$ and establish that ${T}_{E}\ensuremath{\sim}{({\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+})}^{2}/{\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$. The Lyapunov time ${T}_{\mathrm{\ensuremath{\Lambda}}}$ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks ${T}_{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\approx}{\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+}$, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a dynamical glass, where ${T}_{E}$ grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which satisfies ${T}_{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\lesssim}{\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$. This effect arises from the formation of highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of nonchaotic regions. These structures persist up to the ergodization time ${T}_{E}$.
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Dynamical glass in weakly nonintegrable Klein-Gordon chains.
Physical review. E, 2019Co-Authors: Carlo Danieli, David K. Campbell, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a nonintegrable perturbation creates a Coupling Network in action space which can be short or long ranged. We analyze the dynamics of observables which become the conserved actions in the integrable limit. We compute distributions of their finite time averages and obtain the ergodization time scale T_{E} on which these distributions converge to δ distributions. We relate T_{E} to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations σ_{τ}^{+} dominating the means μ_{τ}^{+} and establish that T_{E}∼(σ_{τ}^{+})^{2}/μ_{τ}^{+}. The Lyapunov time T_{Λ} (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks T_{Λ}≈σ_{τ}^{+}, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a dynamical glass, where T_{E} grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which satisfies T_{Λ}≲μ_{τ}^{+}. This effect arises from the formation of highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of nonchaotic regions. These structures persist up to the ergodization time T_{E}.
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Dynamical glass in weakly non-integrable many-body systems
arXiv: Chaotic Dynamics, 2018Co-Authors: David K. Campbell, Carlo Danieli, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a {\it nonintegrable} perturbation creates a Coupling Network in action space which can be short- or long-ranged. We analyze the dynamics of observables which turn into the conserved actions in the integrable limit. We compute distributions of their finite-time averages and obtain the ergodization time scale $T_E$ on which these distributions converge to $\delta$-distributions. We relate $T_E \sim (\sigma_\tau^+)^2/\mu_\tau^+$ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations $\sigma_\tau^+$ dominating the means $\mu_\tau^+$. The Lyapunov time $T_{\Lambda}$ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks $T_{\Lambda}\approx \sigma_\tau^+$, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a {\it dynamical glass}, where $T_E$ grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which $T_{\Lambda} \lesssim \mu_\tau^+$. This is due to the formation of a highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of non-chaotic regions. These structures persist up to the ergodization time $T_E$.
Robert A. York - One of the best experts on this subject based on the ideXlab platform.
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Influence of the oscillator equivalent circuit on the stable modes of parallel-coupled oscillators
IEEE Transactions on Microwave Theory and Techniques, 1997Co-Authors: Heng-chia Chang, E.s. Shapiro, Robert A. YorkAbstract:This paper addresses a deficiency in the authors' previous work on coupled-oscillator theory, involving the nature of the resonance in the oscillator equivalent circuit and its influence on the stable modes of the, coupled-oscillator system. The authors show that series and parallel oscillators with identical free-running characteristics nevertheless behave differently when coupled by the same Coupling Network. The analysis focuses on parallel-Coupling Networks, which are most practical at microwave frequencies, and specifically on nearest-neighbor Coupling topologies. The theory is verified using four small active-patch arrays operating at 10 GHz.
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Oscillator array dynamics with broadband N-port Coupling Networks
IEEE Transactions on Microwave Theory and Techniques, 1994Co-Authors: Robert A. York, P. Liao, J.j. LynchAbstract:This paper considers the analysis of an oscillator array with an arbitrary Coupling Network, described in terms of N-port circuit parameters. A Kurokawa analysis is used to transform the frequency domain Network description into a set of equations for the oscillator amplitude and phase dynamics. The results reduce to previous work with "loosely" coupled Van der Pol oscillators, provided that the Coupling Network satisfies a broadband condition: the Q-factor of the Coupling Network must be much smaller than that of the oscillator. The theory is verified using a new Coupling structure and a six-element patch oscillator array operating at 4 GHz, which produced a 70/spl deg/ scanning range using a phase-shifterless technique. >
Carlo Danieli - One of the best experts on this subject based on the ideXlab platform.
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Dynamical glass in weakly nonintegrable Klein-Gordon chains
Physical Review E, 2019Co-Authors: Carlo Danieli, David K. Campbell, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a nonintegrable perturbation creates a Coupling Network in action space which can be short or long ranged. We analyze the dynamics of observables which become the conserved actions in the integrable limit. We compute distributions of their finite time averages and obtain the ergodization time scale ${T}_{E}$ on which these distributions converge to $\ensuremath{\delta}$ distributions. We relate ${T}_{E}$ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations ${\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+}$ dominating the means ${\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$ and establish that ${T}_{E}\ensuremath{\sim}{({\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+})}^{2}/{\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$. The Lyapunov time ${T}_{\mathrm{\ensuremath{\Lambda}}}$ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks ${T}_{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\approx}{\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+}$, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a dynamical glass, where ${T}_{E}$ grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which satisfies ${T}_{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\lesssim}{\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$. This effect arises from the formation of highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of nonchaotic regions. These structures persist up to the ergodization time ${T}_{E}$.
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Dynamical glass in weakly nonintegrable Klein-Gordon chains.
Physical review. E, 2019Co-Authors: Carlo Danieli, David K. Campbell, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a nonintegrable perturbation creates a Coupling Network in action space which can be short or long ranged. We analyze the dynamics of observables which become the conserved actions in the integrable limit. We compute distributions of their finite time averages and obtain the ergodization time scale T_{E} on which these distributions converge to δ distributions. We relate T_{E} to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations σ_{τ}^{+} dominating the means μ_{τ}^{+} and establish that T_{E}∼(σ_{τ}^{+})^{2}/μ_{τ}^{+}. The Lyapunov time T_{Λ} (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks T_{Λ}≈σ_{τ}^{+}, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a dynamical glass, where T_{E} grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which satisfies T_{Λ}≲μ_{τ}^{+}. This effect arises from the formation of highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of nonchaotic regions. These structures persist up to the ergodization time T_{E}.
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Dynamical glass in weakly non-integrable many-body systems
arXiv: Chaotic Dynamics, 2018Co-Authors: David K. Campbell, Carlo Danieli, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a {\it nonintegrable} perturbation creates a Coupling Network in action space which can be short- or long-ranged. We analyze the dynamics of observables which turn into the conserved actions in the integrable limit. We compute distributions of their finite-time averages and obtain the ergodization time scale $T_E$ on which these distributions converge to $\delta$-distributions. We relate $T_E \sim (\sigma_\tau^+)^2/\mu_\tau^+$ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations $\sigma_\tau^+$ dominating the means $\mu_\tau^+$. The Lyapunov time $T_{\Lambda}$ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks $T_{\Lambda}\approx \sigma_\tau^+$, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a {\it dynamical glass}, where $T_E$ grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which $T_{\Lambda} \lesssim \mu_\tau^+$. This is due to the formation of a highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of non-chaotic regions. These structures persist up to the ergodization time $T_E$.
J. Andersen - One of the best experts on this subject based on the ideXlab platform.
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A practical technique for designing multiport Coupling Networks
IEEE Transactions on Microwave Theory and Techniques, 1996Co-Authors: W.p. Geren, C.r. Curry, J. AndersenAbstract:A new technique is proposed for designing a passive lossless Coupling Network transforming any prescribed N by N symmetric immittance matrix into a corresponding N by N diagonal immittance matrix. A principal application of the technique is in the design of matching Networks between N uncoupled resistive source impedances and planar antenna arrays. The technique is based upon repeated applications of Givens rotations, which can be implemented by a cascade connection of four-port directional couplers. Thus, both in the design technique and in the subsequent hardware implementation, our approach represents a significant departure from past design procedures. Existing synthesis methods involve the use of multiwinding transformers, which are impractical at microwave frequencies.
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ractical Technique for Designing ultiport Coupling Networks
1996Co-Authors: W.p. Geren, C.r. Curry, J. AndersenAbstract:A new technique is proposed for designing a passive lossless Coupling Network transforming any prescribed S by 3- symmetric immittance matrix into a corresponding S by -T diag- onal immittance matrix. A principal application of the technique is in the design of matching Networks between -1- uncoupled resistive source impedances and planar antenna arrays. The tech- nique is based upon repeated applications of Givens rotations (l), which can be implemented by a cascade connection of four-port directional couplers. Thus, both in the design technique and in the subsequent hardware implementation, our approach represents a significant departure from past design procedures. Existing synthesis methods involve the use of multiwinding transformers, which are impractical at microwave frequencies.
Yagmur Kati - One of the best experts on this subject based on the ideXlab platform.
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Dynamical glass in weakly nonintegrable Klein-Gordon chains
Physical Review E, 2019Co-Authors: Carlo Danieli, David K. Campbell, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a nonintegrable perturbation creates a Coupling Network in action space which can be short or long ranged. We analyze the dynamics of observables which become the conserved actions in the integrable limit. We compute distributions of their finite time averages and obtain the ergodization time scale ${T}_{E}$ on which these distributions converge to $\ensuremath{\delta}$ distributions. We relate ${T}_{E}$ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations ${\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+}$ dominating the means ${\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$ and establish that ${T}_{E}\ensuremath{\sim}{({\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+})}^{2}/{\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$. The Lyapunov time ${T}_{\mathrm{\ensuremath{\Lambda}}}$ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks ${T}_{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\approx}{\ensuremath{\sigma}}_{\ensuremath{\tau}}^{+}$, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a dynamical glass, where ${T}_{E}$ grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which satisfies ${T}_{\mathrm{\ensuremath{\Lambda}}}\ensuremath{\lesssim}{\ensuremath{\mu}}_{\ensuremath{\tau}}^{+}$. This effect arises from the formation of highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of nonchaotic regions. These structures persist up to the ergodization time ${T}_{E}$.
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Dynamical glass in weakly nonintegrable Klein-Gordon chains.
Physical review. E, 2019Co-Authors: Carlo Danieli, David K. Campbell, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a nonintegrable perturbation creates a Coupling Network in action space which can be short or long ranged. We analyze the dynamics of observables which become the conserved actions in the integrable limit. We compute distributions of their finite time averages and obtain the ergodization time scale T_{E} on which these distributions converge to δ distributions. We relate T_{E} to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations σ_{τ}^{+} dominating the means μ_{τ}^{+} and establish that T_{E}∼(σ_{τ}^{+})^{2}/μ_{τ}^{+}. The Lyapunov time T_{Λ} (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks T_{Λ}≈σ_{τ}^{+}, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a dynamical glass, where T_{E} grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which satisfies T_{Λ}≲μ_{τ}^{+}. This effect arises from the formation of highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of nonchaotic regions. These structures persist up to the ergodization time T_{E}.
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Dynamical glass in weakly non-integrable many-body systems
arXiv: Chaotic Dynamics, 2018Co-Authors: David K. Campbell, Carlo Danieli, Yagmur Kati, Thudiyangal Mithun, Sergej FlachAbstract:Integrable many-body systems are characterized by a complete set of preserved actions. Close to an integrable limit, a {\it nonintegrable} perturbation creates a Coupling Network in action space which can be short- or long-ranged. We analyze the dynamics of observables which turn into the conserved actions in the integrable limit. We compute distributions of their finite-time averages and obtain the ergodization time scale $T_E$ on which these distributions converge to $\delta$-distributions. We relate $T_E \sim (\sigma_\tau^+)^2/\mu_\tau^+$ to the statistics of fluctuation times of the observables, which acquire fat-tailed distributions with standard deviations $\sigma_\tau^+$ dominating the means $\mu_\tau^+$. The Lyapunov time $T_{\Lambda}$ (the inverse of the largest Lyapunov exponent) is then compared to the above time scales. We use a simple Klein-Gordon chain to emulate long- and short-range Coupling Networks by tuning its energy density. For long-range Coupling Networks $T_{\Lambda}\approx \sigma_\tau^+$, which indicates that the Lyapunov time sets the ergodization time, with chaos quickly diffusing through the Coupling Network. For short-range Coupling Networks we observe a {\it dynamical glass}, where $T_E$ grows dramatically by many orders of magnitude and greatly exceeds the Lyapunov time, which $T_{\Lambda} \lesssim \mu_\tau^+$. This is due to the formation of a highly fragmented inhomogeneous distributions of chaotic groups of actions, separated by growing volumes of non-chaotic regions. These structures persist up to the ergodization time $T_E$.
