Emergent phenomena in Nature: a paradox with Theory?

The existence of various physical phenomena stems from the concept called asymptotic emergence, that is, they seem to be exclusively reserved for certain limiting theories. Important examples are spontaneous symmetry breaking (SSB) and phase transitions: these would only occur in the classical or thermodynamic limit of underlying finite quantum systems, since for finite quantum systems, due to the uniqueness of the relevant states, such phenomena are excluded by Theory. In Nature, however, finite quantum systems describing real materials clearly exhibit such effects. In this paper we discuss these apparently ``paradoxical'' phenomena and outline various ideas and mechanisms that encompass both theory and reality, from physical and mathematical points of view.Comment: 21 pages, 5 figure

DLR-KMS correspondence on lattice spin systems

The Dobrushin-Lanford-Ruelle (DLR) condition and the classical Kubo-Martin-Schwinger (KMS) condition are considered in the context of classical lattice systems. In particular, we prove that these conditions are equivalent for the case of a lattice spin system with values in a compact symplectic manifold by showing that infinite volume Gibbs states are in bijection with KMS states.Comment: 13 page

Aggregated dynamic demand equations for specialistic-outpatient medical care:(Estimated from a time-series of cross-sections)

In this paper a dynamic model is presented which describes the development of the demand for specialistic medical care in The Netherlands, during the period 1960-1972. The "regionally correlated, time-wise auto-regressive" model is consistently estimated from a time-series of cross-sections, using a modified Aitken estimator. The dependent variables are the number of publicly insured patients referred from general care to specialistic care, and the amount of care consumed per patient referred. As independent variables we took demographic factors, the supply of different levels of medical care and the insurance system. The estimation results show a.o. important substitution possibilities between general and specialistic care, and a significant influence of supply and supply-related variables on the demand for specialistic care.</p

Time transients in the quantum corrected Newtonian potential induced by a massless nonminimally coupled scalar field

We calculate the one loop graviton vacuum polarization induced by a massless, nonminimally coupled scalar field on Minkowski background. We make use of the Schwinger-Keldysh formalism, which allows us to study time dependent phenomena. As an application we compute the leading quantum correction to the Newtonian potential of a point particle. The novel aspect of the calculation is the use of the Schwinger-Keldysh formalism, within which we calculate the time transients induced by switching on of the graviton-scalar coupling.Comment: 22 pages, 5 figures; detailed calculation of the graviton vacuum polarization moved to the new Appendix; matches published versio