1,134 research outputs found

    Spectral determinants for Schroedinger equation and Q-operators of Conformal Field Theory

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    Relation between the vacuum eigenvalues of CFT Q-operators and spectral determinants of one-dimensional Schroedinger operator with homogeneous potential, recently conjectured by Dorey and Tateo for special value of Virasoro vacuum parameter p, is proven to hold, with suitable modification of the Schroedinger operator, for all values of p.Comment: 9 pages, harvmac.tex, typos correcte

    Integrable Structure of Conformal Field Theory II. Q-operator and DDV equation

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    This paper is a direct continuation of\ \BLZ\ where we begun the study of the integrable structures in Conformal Field Theory. We show here how to construct the operators Q±(λ){\bf Q}_{\pm}(\lambda) which act in highest weight Virasoro module and commute for different values of the parameter λ\lambda. These operators appear to be the CFT analogs of the QQ - matrix of Baxter\ \Baxn, in particular they satisfy famous Baxter's TQ{\bf T}-{\bf Q} equation. We also show that under natural assumptions about analytic properties of the operators Q(λ){\bf Q}(\lambda) as the functions of λ\lambda the Baxter's relation allows one to derive the nonlinear integral equations of Destri-de Vega (DDV)\ \dVega\ for the eigenvalues of the Q{\bf Q}-operators. We then use the DDV equation to obtain the asymptotic expansions of the Q{\bf Q} - operators at large λ\lambda; it is remarkable that unlike the expansions of the T{\bf T} operators of \ \BLZ, the asymptotic series for Q(λ){\bf Q}(\lambda) contains the ``dual'' nonlocal Integrals of Motion along with the local ones. We also discuss an intriguing relation between the vacuum eigenvalues of the Q{\bf Q} - operators and the stationary transport properties in boundary sine-Gordon model. On this basis we propose a number of new exact results about finite voltage charge transport through the point contact in quantum Hall system.Comment: Revised version, 43 pages, harvmac.tex. Minor changes, references adde

    Friedel oscillations of Density of States in a one-dimensional Mott insulator and Incommensurate Charge Density Wave/Superconductor

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    Oscillations of local density of states generated by a single scalar impurity potential are calculated for one-dimensional systems with dynamically generated charge or spin gap. At zero temperature the oscillations develop at finite wave vector (π\pi for the Mott insulator and 2kF2k_F for ICDW/SC) and at frequencies larger than the soliton spectral gap mm. Their amplitude has a broad maximum at ω3m\omega \approx 3m, where mm is the gap magnitude.Comment: 4 pages, 2 figure

    Transport of interacting electrons through a potential barrier: nonperturbative RG approach

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    We calculate the linear response conductance of electrons in a Luttinger liquid with arbitrary interaction g_2, and subject to a potential barrier of arbitrary strength, as a function of temperature. We first map the Hamiltonian in the basis of scattering states into an effective low energy Hamiltonian in current algebra form. Analyzing the perturbation theory in the fermionic representation the diagrams contributing to the renormalization group (RG) \beta-function are identified. A universal part of the \beta-function is given by a ladder series and summed to all orders in g_2. First non-universal corrections beyond the ladder series are discussed. The RG-equation for the temperature dependent conductance is solved analytically. Our result agrees with known limiting cases.Comment: 6 pages, 5 figure

    Giant neutron halo in nuclei beyond beta-stability line

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    The radii of nucleon distribution and neutron skin in nuclei beyond the \beta-stability line are studied within the extended Thomas-Fermi approximation. We show that the growth of neutron skin in unstable nuclei does not obey the saturation condition because of the neutron coat. The neutron coat indicates the possibility of giant neutron halo which is growing with moving away from the beta stability line. We demonstrate the presence of strong shell oscillations in the charge radius R_C and the relation of R_C to the isospin shift of neutron-proton chemical potentials \Delta\lambda =\lambda_n-\lambda_p for nuclei beyond the beta-stability line at fixed value of mass number A.Comment: 10 pages, 6 figures; few sentences and one reference added; published in Nucl. Phys. At. Energ. V.11, N4, 335 (2010

    Regional Investment Policy Under the Impact of Budget Limitations and Economic Sanctions

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    The article is devoted to the assessment of influence of budgetary restrictions and economic sanctions on investment policy of a region. The paper studies the bilateral negative effect on socio-economic development of regions from both the external sanctions and braking mechanism of economic development within the country. On the basis of the comparative and statistical analysis, the need to change focus of investment policy from the growth in volumes to qualitative perfecting is proved. The new direction of investment policy connected with the import substitution process realization, its combination with acceleration of innovative development on the certain example of Sverdlovsk region is analyzed. The conclusions and offers stated in the article are applicable to the public authorities of subjects of the Russian Federation, experts in the sphere of regional investment policy and improvement of investment climate, and also the specialized organizations specialized in attracting investment and work with investors in regions of Russia
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