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1. Abstract Dynamics: A Progressive Linearization of Nonlinear Dynamics

   Shahhosseini, Amir; D’Souza, Kiran (June 2024, Springer)

   Lacarbonara, Walter (Ed.)

   This work proposes a computational approach that has its roots in the early ideas of local Lyapunov exponents, yet, it offers new perspectives toward analyzing these problems. The method of interest, namely abstract dynamics, is an indirect quantitative measure of the variations of the governing vector fields based on the principles of linear systems. The examples in this work, ranging from simple limit cycles to chaotic attractors, are indicative of the new interpretation that this new perspective can offer. The presented results can be exploited in the structure of algorithms (most prominently machine learning algorithms) that are designed to estimate the complex behavior of nonlinear systems, even chaotic attractors, within their horizon of predictability. 

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2. Multibody dynamics vs. fluid dynamics: two perspectives on the dynamics of granular flows

   Milad Rakhsha, Conlain Kelly (September 2020, Journal of computational and nonlinear dynamics)

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3. Ultrafast Vibrational Dynamics of a Solute Correlates with Dynamics of the Solvent

   Crum, Vivian F.; Kiefer, Laura M.; Kubarych, K. J. (July 2021, Journal of chemical physics)

   null (Ed.)

   Two-dimensional infrared (2D-IR) spectroscopy is used to measure the spectral dynamics of the metal carbonyl complex, cyclopentadienyl manganese tricarbonyl (CMT) in a series of linear alkyl nitriles. 2D-IR spectroscopy provides direct readout of solvation dynamics through spectral diffusion, probing the decay of frequency correlation induced by fluctuations of the solvent environment. 2D-IR simultaneously monitors intramolecular vibrational energy redistribution (IVR) among excited vibrations, which can also be influenced by the solvent through the spectral density rather than the dynamical friction underlying solvation. Here, we report that the CMT vibrational probe reveals solvent dependences in both the spectral diffusion and the IVR time scales, where each slows with increased alkyl chain length. In order to assess the degree to which solute-solvent interactions can be correlated with bulk solvent properties, we compared our results with low-frequency dynamics obtained from optical Kerr effect (OKE) spectroscopy—performed by others—on the same nitrile solvent series. We find excellent correlation between our spectral diffusion results and the orientational dynamics time scales from OKE. We also find a correlation between our IVR time scales and the amplitudes of the low-frequency spectral densities evaluated at the 90-cm-1 energy difference, corresponding to the gap between the two strong vibrational modes of the carbonyl probe. 2D-IR and OKE provide complementary perspectives on condensed phase dynamics, and these findings provide experimental evidence that, at least at the level of dynamical correlations, some aspects of a solute vibrational dynamics can be inferred from properties of the solvent. 

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4. Dynamics of closed singularities

   https://doi.org/10.5802/aif.3343  

   Colding, Tobias Holck; Minicozzi II, William P. (January 2019, Annales de l'Institut Fourier)

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5. Dynamics of quantum information

   https://doi.org/10.1038/s42254-019-0090-y  

   Lewis-Swan, R. J.; Safavi-Naini, A.; Kaufman, A. M.; Rey, A. M. (October 2019, Nature Reviews Physics)