Title: "Towards a "standard model" of liquid state physics"Focus Session: Physics of LiquidsInvited Speaker: Alessio Zaccone*

Our understanding of liquid matter made a leap in 20th century physics thanks to the successful mathematical and numerical development of pair correlation functions, which gave unprecedented insights into the structure of liquids, and provided a well defined route to understand some equilibrium properties (compressibility, equations of state etc). The same is however not true for the dynamical, mechanical and thermodynamic properties of liquids. The most striking example is the inability of celebrated theories to explain the specific heat of liquids or the propagation of acoustic waves in liquids as they are observed experimentally or in simulations. This of course includes the emergence of rigidity as a function of frequency of mechanical oscillation or as a function of confinement, and the Maxwell interpolation between viscous (Newton) and elastic (Hooke) limits, which has remained largely an empirical assumption in many theories of liquids and supercooled liquids, from generalized hydrodynamics to mode-coupling theory. In my talk I will show that these open issues can be understood mechanistically, and in comparison with experiments, by combining advances from three conceptual frameworks: i) the k-gap theory of liquid thermodynamics [1], ii) the Instantaneous Normal Modes theory of liquid dynamics [2-4], and iii) the nonaffine response theory of liquids and glasses [5,6,7]. 

[1] K. Trachenko, Theory of Liquids, Cambridge University Press, 2023

[2] T. Keyes J. Phys. Chem. A 101, 16, 2921–2930 (1997)

[3] A. Zaccone and M. Baggioli PNAS 118 (5) e2022303118 (2021)

[4] C. Stamper et al. J. Phys. Chem. Lett. 2022, 13, 13, 3105–3111 (2022)

[5] A. Zaccone, "Theory of Disordered Solids", Springer, 2023

[6] A. Zaccone, Phys. Rev. E 108, 044101 (2023)

[7] K. Trachenko and A. Zaccone, PNAS 117 (33) 19653-19655 (2020)