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1. Stellar Escape from Globular Clusters. I. Escape Mechanisms and Properties at Ejection

   https://doi.org/10.3847/1538-4357/acbcc1  

   Weatherford, Newlin C.; Kıroğlu, Fulya; Fragione, Giacomo; Chatterjee, Sourav; Kremer, Kyle; Rasio, Frederic A. (April 2023, The Astrophysical Journal)

   Abstract The theory of stellar escape from globular clusters (GCs) dates back nearly a century, especially the gradual evaporation of GCs via two-body relaxation coupled with external tides. More violent ejection can also occur via strong gravitational scattering, supernovae, gravitational wave-driven mergers, tidal disruption events, and physical collisions, but comprehensive study of the many escape mechanisms has been limited. Recent exquisite kinematic data from the Gaia space telescope has revealed numerous stellar streams in the Milky Way (MW) and traced the origin of many to specific MWGCs, highlighting the need for further examination of stellar escape from these clusters. In this study, the first of a series, we lay the groundwork for detailed follow-up comparisons between Cluster Monte Carlo GC models and the latest Gaia data on the outskirts of MWGCs, their tidal tails, and associated streams. We thoroughly review escape mechanisms from GCs and examine their relative contributions to the escape rate, ejection velocities, and escaper demographics. We show for the first time that three-body binary formation may dominate high-speed ejection from typical MWGCs, potentially explaining some of the hypervelocity stars in the MW. Due to their mass, black holes strongly catalyze this process, and their loss at the onset of observable core collapse, characterized by a steep central brightness profile, dramatically curtails three-body binary formation, despite the increased post-collapse density. We also demonstrate that even when born from a thermal eccentricity distribution, escaping binaries have significantly nonthermal eccentricities consistent with the roughly uniform distribution observed in the Galactic field. 

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2. Escape to the Country

   https://doi.org/10.70312/YVDO  

   Besky, Sarah; Tamang, Yojak (June 2025, Limn)

   How has agrarian crisis transformed the interiors of the Himalayan foothills? 

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3. Narrow escape with imperfect reactions

   https://doi.org/10.1103/PhysRevE.110.054127  

   Cengiz, Anıl; Lawley, Sean D (November 2024, Physical Review E)
4. Escape dynamics of confined undulating worms

   https://doi.org/10.1039/D3SM00211J  

   Biswas, Animesh; Kudrolli, Arshad (June 2023, Soft Matter)

   We investigate the escape dynamics of oligochaeta Lumbriculus variegatus by confining them to a quasi-2D circular chamber with a narrow exit passage. The worms move by performing undulatory and peristaltic strokes and use their head to actively probe their surroundings. We show that the worms follow the chamber boundary with occasional reversals in direction and with velocities determined by the orientation angle of the body with respect to the boundary. The average time needed to reach the passage decreases with its width before approaching a constant, consistent with a boundary-following search strategy. We model the search dynamics as a persistent random walk along the boundary and demonstrate that the head increasingly skips over the passage entrance for smaller passage widths due to body undulations. The simulations capture the observed exponential time-distributions taken to reach the exit and their mean as a function of width when starting from random locations. Even after the head penetrates the passage entrance, we find that the worm does not always escape because the head withdraws rhythmically back into the chamber over distances set by the dual stroke amplitudes. Our study highlights the importance of boundary following and body strokes in determining how active matter escapes from enclosed spaces. 

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5. Factors that Impact Photochemical Cage Escape Yields

   https://doi.org/10.1021/acs.chemrev.3c00930  

   Goodwin, Matthew J; Dickenson, John C; Ripak, Alexia; Deetz, Alexander M; McCarthy, Jackson S; Meyer, Gerald J; Troian-Gautier, Ludovic (June 2024, Chemical Reviews)

   The utilization of visible light to mediate chemical reactions in fluid solutions has applications that range from solar fuel production to medicine and organic synthesis. These reactions are typically initiated by electron transfer between a photoexcited dye molecule (a photosensitizer) and a redox-active quencher to yield radical pairs that are intimately associated within a solvent cage. Many of these radicals undergo rapid thermodynamically favored “geminate” recombination and do not diffuse out of the solvent cage that surrounds them. Those that do escape the cage are useful reagents that may undergo subsequent reactions important to the above-mentioned applications. The cage escape process and the factors that determine the yields remain poorly understood despite decades of research motivated by their practical and fundamental importance. Herein, state-of-the-art research on light-induced electron transfer and cage escape that has appeared since the seminal 1972 review by J. P. Lorand entitled “The Cage Effect” is reviewed. This review also provides some background for those new to the field and discusses the cage escape process of both homolytic bond photodissociation and bimolecular light induced electron transfer reactions. The review concludes with some key goals and directions for future research that promise to elevate this very vibrant field to even greater heights. 

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