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arXiv · 2504.16252

Hydrodynamic fields in fluctuating environment: a model for isochoric heat capacity of simple liquids

I. P. de Freitas·F. Sobrero·A. M. S. Macedo·N. F. Svaiter
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Abstract

Using functional methods, we investigate the sound quanta arising from quantized hydrodynamic fields in simple liquids at low temperatures, under the influence of high-energy processes, coming from non-hydrodynamic degrees of freedom. To model these effects on the hydrodynamic fields, we assume that the quantum fields are coupled to an additive, delta-correlated (in space and time) quantum noise field. Thus, the hydrodynamic fields are defined in a fluctuating environment. After defining the generating functional of connected correlation functions in the presence of the noise field, we perform a functional integral over all noise field configurations. This is done using a formal object inspired by the distributional zeta-function method, called the configurational zeta-function. We obtain a new generating functional written in terms of an analytically tractable functional series. This formalism allow us to obtain the excitation spectra of liquids. In the liquid, each term of the series describes the emergent non-interacting elementary excitations with the usual phonon-like dispersion relation and additional excitations with dispersion relations with gaps in pseudo-momentum space. Finally, the behavior of the constant volume specific heat as a function of temperature is obtained for different simple liquids.

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I. P. de Freitas, F. Sobrero, A. M. S. Macedo, N. F. Svaiter. 2025-12-22. Hydrodynamic fields in fluctuating environment: a model for isochoric heat capacity of simple liquids. https://arxiv.org/abs/2504.16252

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