This area is concerned with the study of phenomena which occurred in the Universe. We study mosly chaos, irreversibility and time arrow in the Universe. In order to deeply understand these problems we also consider the Fundation of Quantum Mechanics and Quantum process in the continuum.

Group Members

• Dr. Mario Castagnino
  Group Director
• Dr. Roberto Laura
  Researcher
• Luis Lara
  Researcher
• Dr. Adolfo Ordóñez
  Researcher
• Lic. Rodolfo Id Betan
  Researcher

Financing institution:

CONICET (National Council of Scientific and Technical Research), National University of Rosario. FONCYT.

Project 1:

TITLE: Logical and ontological problems of Theoretical Physics foundation
SUMMARY:

1.- Foundation of Quantum Mechanics:
1.a Analysis of an ontology of relationships.
At the moment we are developing a Modal Interpretation of Quantum Mechanics which it is based on an ontology of properties leading to the Classical Limit, as it has been obtained on the basis of the “Self-induced Decoherence" developed by the group in order to explain the Quantum to Clasical transition of the Universe. A conceptual explanation of T-asymmetric Quantum Mechanics has also been given.
1.b The Classical Limit of Quantum Mechanics
At the moment we are developing a Modal Interpretation of Quantum Mechanics which it is based on an ontology of properties leading to the Classical Limit, as it has been obtained on the basis of the “Self-induced Decoherence" developed by the group in order to explain the Quantum to Clasical transition of the Universe. A conceptual explanation of T-asymmetric Quantum Mechanics has also been given.

2 The time asymmetry problem
Continuing with the subjects of previous researches, the double role played by the momentum energy tensor was described, which due to its symmetry defines both energy flow and momentum density. On the one hand, energy flow can be considered as the local representation of the arrow of time, since it is the local translation of the global arrow defined by the universe asymmetry, as it has already been explained in previous work. On the other hand, momentum density, which is also always present in the semicone of the future, allows us to obtain the third postulate of the Axiomatic Theory of Quantum Fields as a theorem. Collaterally, and preparing possible applications of this subject, brane cosmology was studied, as a dynamic system or as a system capable of defining the arrow of time in such cosmology, and also a cosmological FRW model, minimally coupled with n scale fields, with the same purpose.

PROJECT 2

TITLE: Dynamic systems and cosmology
SUMMARY:

In the analysis of the different cosmological models which are used to study the evolution of the universe, appears complex non-linear differential equations which determine the dynamic behaviour of the physical observables defining the system. In general these equations do not admit explicit solutions, except for cases where severe ad-hoc restrictions are imposed within model parameters. In order to study the behaviour of the solutions to these equations it is necessary to apply the qualitative theory of non-linear differential equations, which is a fundamental branch of the dynamic systems theory. This qualitative theory must be complemented by thorough numerical studies so as to obtain detailed results about the evolution of the system dynamics.

PROJECT 3

TITLE: Methods for the treatment of processes influenced by the continuum in many-body systems
SUMMARY:

Recent developments of radioactive beams have opened the possibility of measuring exotic nuclei far from the stability line, making it possible to study new phenomena, such as many-particle resonances, which we will try to describe using a continuum complex BCS and continuum complex quasiparticle RPA approximations. The treatment of unstable or weakly bound systems requires new study tools strongly connected with the continuous part of the energy spectrum. The methods proposed in this project will be considered within the framework of Many- Body Physics, and can be potentially applied to Nuclear Physics, Atomic Physics, Condensed Matter, etc. As an application of Nuclear Physics we propose to study many-nucleons resonances and study the continuum effects on beta decay and Gamow-Teller resonances in nuclei near thd drip line.

PROJECY 4

TITLE: Applications of many-body theories
SUMMARY:

The aim is to study integrable Hamiltonians in different systems of interest such that Nuclear and Condensed Matter Physics. This type of Hamiltonians allows us to study the influence of bound states on the description of the excitations of many-fermion systems, which could give a simple microscopic perspective to the interacting-boson model. These Hamiltonians are also relevant to the study of Bose condensates and enable the accurate study of the transition zone between BEC and BCS. The use of integrable models to take into account the continuum, by using Richardson’s equations including resonant states, would not only make possible a more precise study of the influence of those states but would also be a way to study these equations through imaginary independent-particle energies.