ИСТИНА

Aggregation kinetics describes the interaction of colliding particle clusters that form larger agglomerates as time goes on. The evolution of cluster size densities in such systems can be efficiently computed via Monte Carlo methods. However, these algorithms experience a significant slowdown during fragmentation events due to the volume of updates for a non-constant number of new particles. In our talk we discuss how to extend two popular Direct Simulation Monte Carlo methods to aggregation processes with collisional fragmentation while preserving their efficiency [1]. We adapt underlying data structures to efficiently handle many updates at once. To demonstrate the applicability of the approaches, we compare their performance and ac- curacy with efficient deterministic finite-difference method applied to the same model [2]. Additionally, we use these methods to verify the existence of oscillating regimes in the aggregation-fragmentation kinetics recently detected in deterministic simulations. We con- firm that steady oscillations of densities are stable with respect to fluctuations and noise. S. M. was supported by Russian Science Foundation (project 21-71-10072). [1] Kalinov A., Osinsky A. I., Matveev S. A., Otieno W., & Brilliantov N. V. (2021). Di- rect simulation Monte Carlo for new regimes in aggregation-fragmentation kinetics. arXiv preprint arXiv:2103.09481. [2] Matveev S. A., Krapivsky P. L., Smirnov A. P., Tyrtyshnikov E. E., & Brilliantov N. V. (2017). Oscillations in aggregation-shattering processes. Physical review letters, 119(26), 260601