1,233 research outputs found

    Interpolation of nonlinear maps

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    Let (X0,X1)(X_0, X_1) and (Y0,Y1)(Y_0, Y_1) be complex Banach couples and assume that X1⊆X0X_1\subseteq X_0 with norms satisfying ∥x∥X0≤c∥x∥X1\|x\|_{X_0} \le c\|x\|_{X_1} for some c>0c > 0. For any 0<θ<10<\theta <1, denote by Xθ=[X0,X1]θX_\theta = [X_0, X_1]_\theta and Yθ=[Y0,Y1]θY_\theta = [Y_0, Y_1]_\theta the complex interpolation spaces and by B(r,Xθ)B(r, X_\theta), 0≤θ≤1,0 \le \theta \le 1, the open ball of radius r>0r>0 in XθX_\theta, centered at zero. Then for any analytic map Φ:B(r,X0)→Y0+Y1\Phi: B(r, X_0) \to Y_0+ Y_1 such that Φ:B(r,X0)→Y0\Phi: B(r, X_0)\to Y_0 and Φ:B(c−1r,X1)→Y1\Phi: B(c^{-1}r, X_1)\to Y_1 are continuous and bounded by constants M0M_0 and M1M_1, respectively, the restriction of Φ\Phi to B(c−θr,Xθ)B(c^{-\theta}r, X_\theta), 0<θ<1,0 < \theta < 1, is shown to be a map with values in YθY_\theta which is analytic and bounded by M01−θM1θM_0^{1-\theta} M_1^\theta

    Birkhoff normal form for the periodic Toda lattice

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    This volume contains the proceedings of a conference held at the Courant Institute in 2006 to celebrate the 60th birthday of Percy A. Deift. The program reflected the wide-ranging contributions of Professor Deift to analysis with emphasis on recent developments in Random Matrix Theory and integrable systems. The articles in this volume present a broad view on the state of the art in these fields. Topics on random matrices include the distributions and stochastic processes associated with local eigenvalue statistics, as well as their appearance in combinatorial models such as TASEP, last passage percolation and tilings. The contributions in integrable systems mostly deal with focusing NLS, the Camassa-Holm equation and the Toda lattice. A number of papers are devoted to techniques that are used in both fields. These techniques are related to orthogonal polynomials, operator determinants, special functions, Riemann-Hilbert problems, direct and inverse spectral theory. Of special interest is the article of Percy Deift in which he discusses some open problems of Random Matrix Theory and the theory of integrable systems

    Global action-angle variables for the periodic Toda lattice

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    In this paper we construct global action-angle variables for the periodic Toda lattic

    Qualitative features of periodic solutions of KdV

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    In this paper we prove new qualitative features of solutions of KdV on the circle. The first result says that the Fourier coefficients of a solution of KdV in Sobolev space HN, N≥0H^N,\, N\geq 0, admit a WKB type expansion up to first order with strongly oscillating phase factors defined in terms of the KdV frequencies. The second result provides estimates for the approximation of such a solution by trigonometric polynomials of sufficiently large degree

    Global Birkhoff coordinates for the periodic Toda lattice

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    In this paper we prove that the periodic Toda lattice admits globally defined Birkhoff coordinates.Comment: 32 page

    Oral Immunization of Wildlife Against Rabies: Concept and First Field Experiments

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    The possibility of immunizing carnivores against rabies with live attenuated vaccine administered by the oral route was raised by North American scientists in the 1960s. Subsequently, several American and European teams tested different vaccine strains in the laboratory for efficacy and safety and studied vaccine stabilization, vaccine delivery systems, baIt acceptance by wl1d ammals, and bait distribution schemes. The first field trial of a cloned SAD (Street Alabama Dufferin) strain in baits designed to immunize foxes orally ~as conducted in an Alpine valley in Switzerland in 1978. A population containing ∼60% immune foxes at the valley entrance stopped the spread of the disease into untreated upper parts of the valley. T~e strategic use of oral vaccination of foxes in additional regions of SWItzerland resulted m freedom from the zoonosis in four-fifths of the countr

    Oral Immunization of Wildlife Against Rabies: Concept and First Field Experiments

    Get PDF
    The possibility of immunizing carnivores against rabies with live attenuated vaccine administered by the oral route was raised by North American scientists in the 1960s. Subsequently, several American and European teams tested different vaccine strains in the laboratory for efficacy and safety and studied vaccine stabilization, vaccine delivery systems, baIt acceptance by wl1d ammals, and bait distribution schemes. The first field trial of a cloned SAD (Street Alabama Dufferin) strain in baits designed to immunize foxes orally ~as conducted in an Alpine valley in Switzerland in 1978. A population containing ∼60% immune foxes at the valley entrance stopped the spread of the disease into untreated upper parts of the valley. T~e strategic use of oral vaccination of foxes in additional regions of SWItzerland resulted m freedom from the zoonosis in four-fifths of the country

    Addition theorems and the Drach superintegrable systems

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    We propose new construction of the polynomial integrals of motion related to the addition theorems. As an example we reconstruct Drach systems and get some new two-dimensional superintegrable Stackel systems with third, fifth and seventh order integrals of motion.Comment: 18 pages, the talk given on the conference "Superintegrable Systems in Classical and Quantum Mechanics", Prague 200

    On geodesic exponential maps of the Virasoro group

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    We study the geodesic exponential maps corresponding to Sobolev type right-invariant (weak) Riemannian metricsμ(k) (k≥ 0) on the Virasoro group Vir and show that for k≥ 2, but not for k=0,1, each of them defines a smooth Fréchet chart of the unital element e ∈Vir. In particular, the geodesic exponential map corresponding to the Korteweg-de Vries (KdV) equation (k=0) is not a local diffeomorphism near the origi

    Dog Ecology and Dog Rabies Control

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    Dog populations, like other populations, depend on the availability of resources (food, water, and shelter). Humans either make available or deliberately withhold resources for varying proportions of dog populations. Dog-keeping practices and the duties of responsible ownership vary with the cultural setting. Dog populations often attain densities that allow the species to be a main host of rabies. The epidemiology of dog rabies is not well understood, despite the easy access to dog populations. Today dog rabies is predomina~t in developing countries. In addition to the high rate of exposure of humans to dogs, tradItional medical beliefs and practices are the most important cultural factors that lead to high numbers of cases of human rabies. Dog rabies control programs have been succe~sful in the past, but most are failing today. Program development should follow managenal principles and take into consideration the biology of dog populations as w~ll as. cultural constraints. Elimination of stray dogs IS not an effIcIent means of controllIng eIther the dog population or rabies, but it may create public awarenes
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