4,449 research outputs found

    Cooling of hypernuclear compact stars

    Full text link
    We study the thermal evolution of hypernuclear compact stars constructed from covariant density functional theory of hypernuclear matter and parameterizations which produce sequences of stars containing two-solar-mass objects. For the input in the simulations, we solve the Bardeen-Cooper-Schrieffer gap equations in the hyperonic sector and obtain the gaps in the spectra of Λ\Lambda, Ξ0\Xi^0 and Ξ\Xi^- hyperons. For the models with masses M/M1.5M/M_{\odot} \ge 1.5 the neutrino cooling is dominated by hyperonic direct Urca processes in general. In the low-mass stars the (Λp)(\Lambda p) plus leptons channel is the dominant direct Urca process, whereas for more massive stars the purely hyperonic channels (ΣΛ)(\Sigma^-\Lambda) and (ΞΛ)(\Xi^-\Lambda) are dominant. Hyperonic pairing strongly suppresses the processes on Ξ\Xi^-s and to a lesser degree on Λ\Lambdas. We find that intermediate-mass 1.5M/M1.81.5 \le M/M_{\odot} \le 1.8 models have surface temperatures which lie within the range inferred from thermally emitting neutron stars, if the hyperonic pairing is taken into account. Most massive models with M/M2M/M_{\odot} \simeq 2 may cool very fast via the direct Urca process through the (Λp)(\Lambda p) channel because they develop inner cores where the SS-wave pairing of Λ\Lambdas and proton is absent.Comment: v2: minor changes, matches published version, 11 pages, 9 figure

    Quantum Oscillator on \DC P^n in a constant magnetic field

    Full text link
    We construct the quantum oscillator interacting with a constant magnetic field on complex projective spaces \DC P^N, as well as on their non-compact counterparts, i. e. the NN-dimensional Lobachewski spaces LN{\cal L}_N. We find the spectrum of this system and the complete basis of wavefunctions. Surprisingly, the inclusion of a magnetic field does not yield any qualitative change in the energy spectrum. For N>1N>1 the magnetic field does not break the superintegrability of the system, whereas for N=1 it preserves the exact solvability of the system. We extend this results to the cones constructed over \DC P^N and LN{\cal L}_N, and perform the (Kustaanheimo-Stiefel) transformation of these systems to the three-dimensional Coulomb-like systems.Comment: 9 pages, 1 figur

    Spontaneous dressed-state polarization in the strong driving regime of cavity QED

    Get PDF
    We utilize high-bandwidth phase quadrature homodyne measurement of the light transmitted through a Fabry-Perot cavity, driven strongly and on resonance, to detect excess phase noise induced by a single intracavity atom. We analyze the correlation properties and driving-strength dependence of the atom-induced phase noise to establish that it corresponds to the long-predicted phenomenon of spontaneous dressed-state polarization. Our experiment thus provides a demonstration of cavity quantum electrodynamics in the strong driving regime, in which one atom interacts strongly with a many-photon cavity field to produce novel quantum stochastic behavior.Comment: 4 pages, 4 color figure

    Analisis Ekonomi Perkebunan Kelapa dalam terhadap Perekonomian Wilayah Kabupaten Tanjung Jabung Timur

    Full text link
    Penelitian ini dilaksanakan dengan tujuan untuk mengetahui perkembangan perkebunan kelapa dalam di Kabupaten Tanjung Jabung Timur dan untuk mengetahui peranan perkebunan kelapa dalam terhadap pembangunan ekonomi wilayah di kabupaten Tanjung Jabung Timur. Metode analisis data yang digunakan adalah dengan menggunakan formulasi Location Quotien (LQ) dan Multiplier Sektor. Dari analisis yang dilakukan diperoleh bahwa perkembangan tanaman kelapa dalam berdasarkan luas tanamsecara umum stabil, tetapi pada tahun 2003 dan 2004 meningkat karena ada pertambahan perluasan tanaman belum menghasilkan. Selanjutnya pada tahun 2005 – 2010 perkembangannya stabil.Dilihat dari hasil analisis LQ perkembangan perkebunan kelapa dalam pada tahun 2001 – 2010 dengan indikator pendapatan dan indikator tenaga kerja besar dari satu (LQ >1). Perkebunan kelapa dalam di Kabupaten Tanjung jabung Timur memegang peranan dalam menggerakkan perekonomian wilayah Kabupaten Tanjung Jabung Timur dan memiliki efek pengganda sebesar 57,12 atas dasar harga berlaku dan 62,78 atas dasar harga konstan. Sedangkan untuk rata – rata multiplier tenaga kerja jangka pendek sebesar 3,98

    Transferring elements of a density matrix

    Full text link
    We study restrictions imposed by quantum mechanics on the process of matrix elements transfer. This problem is at the core of quantum measurements and state transfer. Given two systems \A and \B with initial density matrices λ\lambda and rr, respectively, we consider interactions that lead to transferring certain matrix elements of unknown λ\lambda into those of the final state r~{\widetilde r} of \B. We find that this process eliminates the memory on the transferred (or certain other) matrix elements from the final state of \A. If one diagonal matrix element is transferred, r~aa=λaa{\widetilde r}_{aa}=\lambda_{aa}, the memory on each non-diagonal element λab\lambda_{a\not=b} is completely eliminated from the final density operator of \A. Consider the following three quantities \Re \la_{a\not =b}, \Im \la_{a\not =b} and \la_{aa}-\la_{bb} (the real and imaginary part of a non-diagonal element and the corresponding difference between diagonal elements). Transferring one of them, e.g., \Re\tir_{a\not = b}=\Re\la_{a\not = b}, erases the memory on two others from the final state of \A. Generalization of these set-ups to a finite-accuracy transfer brings in a trade-off between the accuracy and the amount of preserved memory. This trade-off is expressed via system-independent uncertainty relations which account for local aspects of the accuracy-disturbance trade-off in quantum measurements.Comment: 9 pages, 2 table

    Documenting and modeling the accretion of surface and subsoil organic carbon in agricultural Inceptisols reclaimed from Mediterranean sea marshes in Sardinia

    Get PDF
    High input agriculture in productive Inceptisols that were reclaimed from sea marshes offers an opportunity to study the increase of soil organic carbon (SOC) in soils with originally low SOC. We documented the current SOC content and its distribution with depth for several soil profiles

    Nonlinear behavior of shells of revolution under cyclic loading

    Get PDF
    A large deflection elastic-plastic analysis is presented, applicable to orthotropic axisymmetric plates and shells of revolution subjected to monotonic and cyclic loading conditions. The analysis is based on the finite-element method. It employs a new higher order, fully compatible, doubly curved orthotropic shell-of-revolution element using cubic Hermitian expansions for both meridional and normal displacements. Both perfectly plastic and strain hardening behavior are considered. Strain hardening is incorporated through use of the Prager-Ziegler kinematic hardening theory, which predicts an ideal Bauschinger effect. Numerous sample problems involving monotonic and cyclic loading conditions are analyzed. The monotonic results are compared with other theoretical solutions
    corecore