6 research outputs found

    Ultrazimne gazy atomowe w nieabelowych sztucznych polach cechowania

    Get PDF
    The focus of this thesis is in the area of Abelian and non-Abelian gauge fields th a t can be efficiently simulated in ultracold atomic systems. These exotic fields and their impact on fermionic particles is studied in the context of two-dimensional systems mainly in optical lattices, th a t also are available with current experimental techniques. Behaviour of a particle under the influence of such non-Abelian gauge field is contrasted with the standard case of homogeneous magnetic field. Its spectrum and the transport properties such as quantum Hall effect are investigated. The conditions for the energy bands to form a Hofstadter-butterfly-like gaps in a non-Abelian field are given. We show th a t as long as the Wilson loop for the field is constant, its non-Abelian character does not destroy the big gaps and hence, allows for the integer quantum Hall effect (IQHE). A family of new butterfly spectra is found and the modified IQHE is calculated with the use of Chern numbers. Further, the spectrum of the system is studied in detail and it is demonstrated th a t it can exhibit anomalies i.e. Dirac cones. The elementary excitations of a system with such spectrum are massless fermions traveling with a modified speed of light similarly to the Majorana fermions in the graphene described by the Dirac equation. We further show th a t in the case of synthetic non-Abelian gauge field these cones can be squeezed and the speed of light then depends on the direction. Under the conditions of such squeezing the interactions are considered and the first steps towards the analysis of the Fractional quantum Hall effect (FQHE) in the presence of non-Abelian field are done. The matrix elements of the interaction matrix are analytically calculated

    Fermi-Dirac statistics and the number theory

    Full text link
    We relate the Fermi-Dirac statistics of an ideal Fermi gas in a harmonic trap to partitions of given integers into distinct parts, studied in number theory. Using methods of quantum statistical physics we derive analytic expressions for cumulants of the probability distribution of the number of different partitions.Comment: 7pages, 2 figures, epl.cls, revised versio

    Effect of vibrotherapy on body fatness, blood parameters and fibrinogen concentration in elderly Men

    No full text
    Elderly people need activities that will positively contribute to a satisfactory process of getting older. Vibration training uses mechanical stimulus of a vibrational character that, similarly to other forms of physical activity, affects metabolic processes and conditions of health. The aim of this work was to assess the influence of thirty vibration treatments on body fatness, hematologic and rheologic indexes of blood, and proteinogram and fibrinogen concentration in elderly men’s blood. The study included twenty-one males, aged 60–70 years (mean age 65.3 ± 2.7), who were randomly assigned into a vibrotherapy group (VG) and took part in interventions on mattresses generating oscillatory-cycloid vibrations, and a control group (CG), without interventions. In all patients the following assessments were performed twice: an assessment of body fatness using the bioimpedance method, a complete blood count with a hematology analyzer, and erythrocyte aggregation by a laser-optical rotational cell analyzer; whereas, total plasma protein and fibrinogen values were established, respectively, by biuret and spectrophotometric methods. In order to compare the impact of vibrotherapy on changes in the analyzed variables, analysis of variance (ANOVA) or the Wilcoxon test were used. After applying thirty vibration treatments in the VG, a significant decrease in body fatness parameters was confirmed: BM (∆BM: −2.7 ± 2.0; p = 0.002), BMI (∆BMI: −0.9 ± 0.7; p = 0.002), BF (∆BF: −2.5 ± 2.5; p = 0.013), and %BF (∆%BF: −2.0 ± 2.7; p = 0.041), as well as in RBC (∆RBC: −0.1 ± 0.1; p = 0.035). However, changes in erythrocyte aggregation and proteinogram were not confirmed. It was found that after thirty treatments with VG, a significant decrease of fibrinogen level took place (∆ = −0.3 ± 0.3, p = 0.005). Application of thirty vibrotherapy treatments positively affected body fatness parameters and fibrinogen concentrations in the examined. However, further research should include a greater number of participants
    corecore