Memory effects in a gas of viscoelastic particles Mompó, E. López Castaño, M. A. Lasanta Becerra, Antonio Vega Reyes, F. Torrente, A. This work has been partially funded by the Spanish Ministerio de Ciencia, Innovaci on y Universidades and the Agencia Estatal de Investigaci on through Grant Nos. MTM2017-84446-C2–2-R (A.L., E.M., and A.T.), FIS2017-84440-C2–2-P (A.T.), and FIS2016- 76359-P. (F.V.R.). M.A.L.C. and F.V.R. also acknowledge support from the regional Extremadura Government through Project Nos. GR18079 and IB16087. Computing facilities from the Extremadura Research Centre for Advanced Technologies (CETA-CIEMAT) are also acknowledged. All grants and facilities were provided with partial support from the ERDF. The data that support the findings of this study are available from the corresponding author upon reasonable request. We study a granular gas of viscoelastic particles (kinetic energy loss upon collision is a function of the particles’ relative velocities at impact) subject to a stochastic thermostat. We show that the system displays anomalous cooling and heating rates during thermal relaxation processes, this causing the emergence of thermal memory. In particular, a significant Mpemba effect is present, i.e., an initially hotter/cooler granular gas can cool down/heat up faster than an in comparison cooler/hotter granular gas. Moreover, a Kovacs effect is also observed, i.e., a nonmonotonic relaxation of the granular temperature—if the gas undergoes certain sudden temperature changes before fixing its value. Our results show that both memory effects have distinct features, very different and eventually opposed to those reported in theory for granular fluids under simpler collisional models. We study our system via three independent methods: approximate solution of the kinetic equation time evolution and computer simulations (both molecular dynamics simulations and direct simulation Monte Carlo method), finding good agreement between them. 2021-07-05T10:07:11Z 2021-07-05T10:07:11Z 2022-06-03 2021-06-03 journal article Fluids 33, 062005 (2021); [https://doi.org/10.1063/5.0050804] http://hdl.handle.net/10481/69511 10.1063/5.0050804 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ embargoed access Atribución-NoComercial-SinDerivadas 3.0 España AIP Publishing