A Numerical Renormalization Group for Continuum One-Dimensional Systems

We present a renormalization group (RG) procedure which works naturally on a wide class of interacting one-dimension models based on perturbed (possibly strongly) continuum conformal and integrable models. This procedure integrates Kenneth Wilson's numerical renormalization group with Al. B. Zamolodchikov's truncated conformal spectrum approach. Key to the method is that such theories provide a set of completely understood eigenstates for which matrix elements can be exactly computed. In this procedure the RG flow of physical observables can be studied both numerically and analytically. To demonstrate the approach, we study the spectrum of a pair of coupled quantum Ising chains and correlation functions in a single quantum Ising chain in the presence of a magnetic field.Comment: 4 pages, 4 figure

Nonlinear multi-parameter eigenvalue problems for systems of nonlinear ordinary differential equations arising in electromagnetics

We investigate a generalization of one-parameter eigenvalue problems arising in the theory of nonlinear waveguides to a more general nonlinear multiparameter eigenvalue problem for a nonlinear operator. Using an integral equation approach, we derive functional dispersion equations whose roots yield the desired eigenvalues. The existence and distribution of roots are veried

Mathematical theory of normal waves in an open metal-dielectric regular waveguide of arbitrary cross section

The problem of normal waves in an open metal-dielectric regular waveguide of arbitrary cross-section is considered. This problem is reduced to the boundary eigenvalue problem for longitudinal components of electromagnetic field in Sobolev spaces. To find the solution, we use the variational formulation of the problem. The variational problem is reduced to study of an operator-function. Discreteness of the spectrum is proved and distribution of the characteristic numbers of the operatorfunction on the complex plane is found

Nuclear physics for geo-neutrino studies

Geo-neutrino studies are based on theoretical estimates of geo-neutrino spectra. We propose a method for a direct measurement of the energy distribution of antineutrinos from decays of long-lived radioactive isotopes. We present preliminary results for the geo-neutrinos from Bi-214 decay, a process which accounts for about one half of the total geo-neutrino signal. The feeding probability of the lowest state of Bi-214 - the most important for geo-neutrino signal - is found to be p_0 = 0.177 \pm 0.004 (stat) ^{+0.003}_{-0.001} (sys), under the hypothesis of Universal Neutrino Spectrum Shape (UNSS). This value is consistent with the (indirect) estimate of the Table of Isotopes (ToI). We show that achievable larger statistics and reduction of systematics should allow to test possible distortions of the neutrino spectrum from that predicted using the UNSS hypothesis. Implications on the geo-neutrino signal are discussed.Comment: 8 pages RevTex format, 8 figures and 2 tables. Submitted to PR

Облачные вычисления: история и влияние на будущее библиотек

The background of cloud computing, key characteristics and terminology problems are discussed; deployment models and cloud services are introduced; the positive features and drawbacks are described. Cloud technologies impact on libraries and community at large is emphasized.В статье раскрыты история возникновения облачных вычислений, проблемы терминологии. Представлены основные характеристики облачных вычислений, модели развёртывания и обслуживания; выделены их положительные и отрицательные стороны. Отмечено влияние облачных вычислений как на библиотеки, так и на общество в целом. Подчёркнуто, что с их появлением возросла вероятность выживания библиотек