1,063 research outputs found
Exclusonic Quasiparticles and Thermodynamics of Fractional Quantum Hall Liquids
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 ( 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
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 invariant CFTs we find a generalization
of Gentile parafermions, and we obtain new distributions for the simplest
-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
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
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
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
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
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 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
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)
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
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 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.
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