1,063 research outputs found

    Exclusonic Quasiparticles and Thermodynamics of Fractional Quantum Hall Liquids

    Full text link
    Quasielectrons and quasiholes in the fractional quantum Hall liquids obey fractional (including nontrivial mutual) exclusion statistics. Their statistics matrix can be determined from several possible state-counting scheme, involving different assumptions on statistical correlations. Thermal activation of quasiparticle pairs and thermodynamic properties of the fractional quantum Hall liquids near fillings 1/m1/m (mm odd) at low temperature are studied in the approximation of generalized ideal gas. The existence of hierarchical states in the fractional quantum Hall effect is shown to be a manifestation of the exclusonic nature of the relevant quasiparticles. For magnetic properties, a paramagnetism-diamagnetism transition appears to be possible at finite temperature.Comment: latex209, REVTE

    Exclusion Statistics in Conformal Field Theory Spectra

    Get PDF
    We propose a new method for investigating the exclusion statistics of quasi-particles in Conformal Field Theory (CFT) spectra. The method leads to one-particle distribution functions, which generalize the Fermi-Dirac distribution. For the simplest su(n)su(n) invariant CFTs we find a generalization of Gentile parafermions, and we obtain new distributions for the simplest ZNZ_N-invariant CFTs. In special examples, our approach reproduces distributions based on `fractional exclusion statistics' in the sense of Haldane. We comment on applications to fractional quantum Hall effect edge theories.Comment: 4 pages, 1 figure, LaTeX (uses revtex

    Thermoacoustic tomography arising in brain imaging

    Full text link
    We study the mathematical model of thermoacoustic and photoacoustic tomography when the sound speed has a jump across a smooth surface. This models the change of the sound speed in the skull when trying to image the human brain. We derive an explicit inversion formula in the form of a convergent Neumann series under the assumptions that all singularities from the support of the source reach the boundary

    On the virial coefficients of nonabelian anyons

    Get PDF
    We study a system of nonabelian anyons in the lowest Landau level of a strong magnetic field. Using diagrammatic techniques, we prove that the virial coefficients do not depend on the statistics parameter. This is true for all representations of all nonabelian groups for the statistics of the particles and relies solely on the fact that the effective statistical interaction is a traceless operator.Comment: 9 pages, 3 eps figure

    Exclusion statistics,operator algebras and Fock space representations

    Full text link
    We study exclusion statistics within the second quantized approach. We consider operator algebras with positive definite Fock space and restrict them in a such a way that certain state vectors in Fock space are forbidden ab initio.We describe three characteristic examples of such exclusion, namely exclusion on the base space which is characterized by states with specific constraint on quantum numbers belonging to base space M (e.g. Calogero-Sutherland type of exclusion statistics), exclusion in the single-oscillator Fock space, where some states in single oscillator Fock space are forbidden (e.g. the Gentile realization of exclusion statistics) and a combination of these two exclusions (e.g. Green's realization of para-Fermi statistics). For these types of exclusions we discuss extended Haldane statistics parameters g, recently introduced by two of us in Mod.Phys.Lett.A 11, 3081 (1996), and associated counting rules. Within these three types of exclusions in Fock space the original Haldane exclusion statistics cannot be realized.Comment: Latex,31 pages,no figures,to appear in J.Phys.A : Math.Ge

    Collective excitations in the Unitary Correlation Operator Method and relativistic QRPA studies of exotic nuclei

    Full text link
    The collective excitation phenomena in atomic nuclei are studied in two different formulations of the Random Phase Approximation (RPA): (i) RPA based on correlated realistic nucleon-nucleon interactions constructed within the Unitary Correlation Operator Method (UCOM), and (ii) relativistic RPA (RRPA) derived from effective Lagrangians with density-dependent meson-exchange interactions. The former includes the dominant interaction-induced short-range central and tensor correlations by means of an unitary transformation. It is shown that UCOM-RPA correlations induced by collective nuclear vibrations recover a part of the residual long-range correlations that are not explicitly included in the UCOM Hartree-Fock ground state. Both RPA models are employed in studies of the isoscalar monopole resonance (ISGMR) in closed-shell nuclei across the nuclide chart, with an emphasis on the sensitivity of its properties on the constraints for the range of the UCOM correlation functions. Within the Relativistic Quasiparticle RPA (RQRPA) based on Relativistic Hartree-Bogoliubov model, the occurrence of pronounced low-lying dipole excitations is predicted in nuclei towards the proton drip-line. From the analysis of the transition densities and the structure of the RQRPA amplitudes, it is shown that these states correspond to the proton pygmy dipole resonance.Comment: 15 pages, 4 figures, submitted to Physics of Atomic Nuclei, conference proceedings, "Frontiers in the Physics of Nucleus", St. Petersburg, 28. June-1. July, 200

    Analysis of Shot Noise at Finite Temperatures in Fractional Quantum Hall Edge States

    Full text link
    We investigate shot noise at {\it finite temperatures} induced by the quasi-particle tunneling between fractional quantum Hall (FQH) edge states. The resulting Fano factor has the peak structure at a certain bias voltage. Such a structure indicates that quasi-particles are weakly {\it glued} due to thermal fluctuation. We show that the effect makes it possible to probe the difference of statistics between ν=1/5,2/5\nu=1/5,{}2/5 FQH states where quasi-particles have the same unit charge.Finally we propose a way to indirectly obtain statistical angle in hierarchical FQH states.Comment: 5 pages, 3 figure

    Haldane's Fractional Statistics and the Lowest Landau Level on a Torus

    Full text link
    The Lowest Landau Level on a torus is studied. The dimension of the many-body Hilbert space is obtained and is found to be different from the formula given by Haldane. Our result can be tested in numerical investigations of the low-energy spectrum of fractional quantum Hall states on a torus.Comment: 4 pages, Revtex. Small modifications. The modified version to appear in Phys. Rev. Lett., Feb., 199

    Epidemiology of cardiovascular diseases among patients with diabetes mellitus according to the federal diabetes register of the Russian Federation (2013–2016)

    Get PDF
    BACKGROUND: Cardiovascular diseases (CVD) are the main cause of death for patients with diabetes mellitus (DM). AIMS: To evaluate the CVD epidemiology: coronary heart disease (CHD), myocardial infarction (MI) and cerebrovascular diseases in adult patients with type 1 (T1DM) and type 2 (T2DM) diabetes, compare dynamics with data of implementation of the Federal Program «Diabetes mellitus» in 2007–2012 and over the online period 2013–2016. MATERIALS AND METHODS: The database of the Federal Diabetes register (81 regions at 12.2017). We estimated prevalence and incidence rates/10 thousand (th) adult DM patients over 18 years. RESULTS: The prevalence of CVD for the period 2007 – 2016 significant decreased in CHD for T1DM from 14,9% to 3,5%, for T2DM from 20,1% to 11,7%; MI for T1DM from 5,7% to 1,3%, for T2DM from 7,6% to 3,5%; cerebrovascular diseases for T1DM from 4,9% to 1,7%, for T2DM from 7,6% to 4,3%, respectively. In 2013→2016 positive trends continued: MI for T1DM 8,2→5,9/10th patients, for T2DM 19,2→14,7/10th patients, respectively; CVD for T1DM 11,3→10,5, for T2DM 29,4→25,4/10th patients, respectively. There was a large heterogeneity of the prevalence of CVD in the regions. MI varied in patients for T1DM from 319/10 th patients to absence, for T2DM from 800 to 7/10 th patients; the development of cerebrovascular diseases for T2DM from 900 to less than 100/10 th patients, which is largely due to differences in their registration. A small number of cases may be due to insufficient filling of the database, the facts of a huge number require further analysis. The average age of development of MI had increased: for T1DM 51,2→53 years, for T2DM 63,5→65 years, cerebrovascular diseases for T1DM 52,3→52.5 years, for T2DM 65,2→66,5, respectively. CONCLUSIONS: The prevalence of CVD significantly decreased in the Russian Federation compared to 2007–2012, as well as for the period 2013–2016: the prevalence of CHD and cerebrovascular diseases declined, the number of new cases of MI decreased, the average age and duration of DM before the development of CVD significantly increased. These data reflect the results of the program for improvement medical care and prevention measures for patients with diabetes

    Entropic C-theorems in free and interacting two-dimensional field theories

    Get PDF
    The relative entropy in two-dimensional field theory is studied on a cylinder geometry, interpreted as finite-temperature field theory. The width of the cylinder provides an infrared scale that allows us to define a dimensionless relative entropy analogous to Zamolodchikov's cc function. The one-dimensional quantum thermodynamic entropy gives rise to another monotonic dimensionless quantity. I illustrate these monotonicity theorems with examples ranging from free field theories to interacting models soluble with the thermodynamic Bethe ansatz. Both dimensionless entropies are explicitly shown to be monotonic in the examples that we analyze.Comment: 34 pages, 3 figures (8 EPS files), Latex2e file, continuation of hep-th/9710241; rigorous analysis of sufficient conditions for universality of the dimensionless relative entropy, more detailed discussion of the relation with Zamolodchikov's theorem, references added; to appear in Phys. Rev.
    corecore