University of Potsdam

About: University of Potsdam is a education organization based out in Potsdam, Germany. It is known for research contribution in the topics: Population & Computer science. The organization has 9629 authors who have published 26740 publications receiving 759745 citations. The organization is also known as: Universität Potsdam.

A quantum central limit theorem for non-equilibrium systems: exact local relaxation of correlated states

Abstract: We prove that quantum many-body systems on a one-dimensional lattice locally relax to Gaussian states under non-equilibrium dynamics generated by a bosonic quadratic Hamiltonian. This is true for a large class of initial states—pure or mixed—which have to satisfy merely weak conditions concerning the decay of correlations. The considered setting is a proven instance of a situation where dynamically evolving closed quantum systems locally appear as if they had truly relaxed, to maximum entropy states for fixed second moments. This furthers the understanding of relaxation in suddenly quenched quantum many-body systems. The proof features a non-commutative central limit theorem for non-i.i.d. random variables, showing convergence to Gaussian characteristic functions, giving rise to trace-norm closeness. We briefly link our findings to the ideas of typicality and concentration of measure.

Changes in stress and recovery in elite rowers during preparation for the Olympic Games.

Abstract: Purpose: The purpose was to investigate changes in stress and recovery during preparation for the 1996 Atlanta Olympic Games. Methods: Eleven elite rowers of the German National Rowing Team completed four times the Recovery-Stress-Questionnaire for Athletes (RESTQ-Sport). The eight rowers who competed at the Olympic Games filled out the RESTQ-Sport a fifth time, 2 d before the preliminaries. Results: Trend parameters revealed significant alterations of somatic components of stress (Lack of Energy, Somatic Complaints, Fitness/Injury) and recovery factors (Fitness/Being in Shape) over time that mirrored the average length of daily extensive endurance training sessions. Significant changes in the scales Conflicts/Pressure and Social Relaxation reflected interpersonal processes within the team. Conclusions: The importance of balancing training stress and recovery for an optimal performance development is highlighted as well as the potential of the RESTQ-Sport for training monitoring.