Tsv. D. TSVETKOV, G. PETROV and P. TSVETKOVA

*Institute of Cryobiology and Food Technologies, BG - 1407 Sofia, Bulgaria*

TSVETKOV, Tsv. D., G. PETROV and P. TSVETKOVA, 2008. Non equilibrium thermodynamics by vacuum energy momentum tensor of interacting quantum fields and living cells.* Bulg. J. Agric. Sci.,* 14: 351-356

From the theory and experiment to day it’s known the vacuum as a ground state of the quantum field. It is not just “nothing” but has a rich structure, which determines its possible seeing or virtual excitations, the particle spectrum. At the molecular level with thermodynamic behaviour is considered by any electromagnetic quantum field that the additional boundaries as by the Casimir effect changes the energy of the vacuum and then it depends from the distance between the boundaries, the two parallel, perfectly conducting square plates (side L, distance d, L>d), moved inertial to each other, so that the so-called Casimir force can be calculated theoretically. The Casimir force for electromagnetic field has been measured with great accuracy, proving at its best the physical reality and non-triviality of the quantum vacuum.

Also during phase transitions (e.g. the contributions of the living cells environmental “freeze-drying” and vacuum sublimation for intracellular and extracellular ice formation after sublimate condensation and the following vitrification of the living cells (Tsvetkov et al., 2004, 2005, 2006, 2007) the possible elementary excitations of the fields and therefore the quantum vacuum energy change in a well-defined calculable way. Furthermore, the presence of a positively charged atomic nucleus changes the vacuum energy and thereby affects the atomic energy spectra.

Changes of the vacuum energy produce measurable physical effects. However, its absolute value affects only the gravitational field. It knows that only the quantum vacuum field and the gravitational field influence the living cells at the nano-physical dimensional molecular distance. A even though the absolute value of the vacuum energy cannot be determined. But gravity depends on this absolute value in exactly the same way as it depends on the so-called cosmological constant. The cosmological term is exactly equivalent to a vacuum energy. Vacuum energy and the cosmological constant cannot be distinguished by any experiment and are therefore physically equivalent. The gravitational field, which defines the metric and curvature of space-time, is determined by the sum of all forms of energy and momentum. By symmetry reasons, the so-called energy momentum tensor of the vacuum must be of a form such that its pressure is exactly the negative of its energy density or from the analysis of the linear partial differential equation this local entities of the energy momentum tensor must fulfil kinematical conditions. If the energy density of the vacuum is positive, its pressure is thus necessarily negative. For the temperatures T’ < T (Mitter and Robaschik, 1999) the external pressure by the thermodynamic behaviour of the electromagnetic quantum field with a Casimir effect is reduced in comparison with the standard situation (T’ = T). Therefore it is expected the existence of a certain distance d0, at which the Casimir attraction is compensated by the net radiation pressure.

The freedom to add a cosmological constant corresponds to the freedom to choose the absolute scale of the vacuum energy and both of them should be chosen so that they cancel each other and have no net observational consequence, also gravitationally. We hoped, that a consistent theory of quantum gravity, once found, would tell us how to do this in detail and to understand better the so-called third low of the thermodynamics.

From a great interest is the so-called problem of the connection between the second low of the thermodynamics also the entropy and the time arrow.

Three-privileged direction of time must enter the theory: one in logic (for the time ordering of predicates in history or by the definition of the causality in the time products of the field operators in the interacting quantum field in the S-matrix theories by Bogolubov, N.N.) one for decoherences (as an irreversible process, e.g. scattering processes and the fulfilness of the localisation condition), and the familiar one from the thermodynamics. The three of them must necessarily coincide. The most interesting aspect of these result is certainly that the breaking of time reversal symmetry is not primarily dynamically but logical or that is connected with kinematical conditions between physically measured entities as by deep inelastic scattering and a matter of interpretation at least from the present point.