11,722 research outputs found

    Orbital Perturbations of the Galilean Satellites During Planetary Encounters

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    The Nice model of the dynamical instability and migration of the giant planets can explain many properties of the present Solar System, and can be used to constrain its early architecture. In the jumping-Jupiter version of the Nice model, required from the terrestrial planet constraint and dynamical structure of the asteroid belt, Jupiter has encounters with an ice giant. Here we study the survival of the Galilean satellites in the jumping-Jupiter model. This is an important concern because the ice-giant encounters, if deep enough, could dynamically perturb the orbits of the Galilean satellites, and lead to implausible results. We performed numerical integrations where we tracked the effect of planetary encounters on the Galilean moons. We considered three instability cases from Nesvorny & Morbidelli (2012) that differed in the number and distribution of encounters. We found that in one case, where the number of close encounters was relatively small, the Galilean satellite orbits were not significantly affected. In the other two, the orbital eccentricities of all moons were excited by encounters, Callisto's semimajor axis changed, and, in a large fraction of trials, the Laplace resonance of the inner three moons was disrupted. The subsequent evolution by tides damps eccentricities and can recapture the moons in the Laplace resonance. A more important constraint is represented by the orbital inclinations of the moons, which can be excited during the encounters and not appreciably damped by tides. We find that one instability case taken from Nesvorny & Morbidelli (2012) clearly fails this constraint. This shows how the regular satellites of Jupiter can be used to set limits on the properties of encounters in the jumping-Jupiter model, and help us to better understand how the early Solar System evolved.Comment: The Astronomical Journal, in pres

    Large scale CMB anomalies from thawing cosmic strings

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    Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings imprint their signature in the Cosmic Microwave Background (CMB) Anisotropies after recombination. Being almost frozen in the Hubble flow, these strings are quasi static and evade almost all of the previously derived constraints on their tension while being able to source large scale anisotropies in the CMB sky. Using a local variance estimator on thousand of numerically simulated Nambu-Goto all sky maps, we compute the expected signal and show that it can mimic a dipole modulation at large angular scales while being negligible at small angles. Interestingly, such a scenario generically produces one cold spot from the thawing of a cosmic string loop. Mixed with anisotropies of inflationary origin, we find that a few strings of tension GU = O(1) x 10^(-6) match the amplitude of the dipole modulation reported in the Planck satellite measurements and could be at the origin of other large scale anomalies.Comment: 23 pages, 11 figures, uses jcappub. References added, matches published versio

    Interaction between fk506 and clotrimazole in a liver transplant recipient

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    Role of strong correlation in the recent ARPES experiments for cuprate superconductors

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    Motivated by recent photoemission experiments on cuprates, the low-lying excitations of a strongly correlated superconducting state are studied numerically. It is observed that along the nodal direction these low-lying one-particle excitations show a linear momentum dependence for a wide range of excitation energies and, thus, they do not present a kink-like structure. The nodal Fermi velocity vFv_{\rm F}, as well as other observables, are systematically evaluated directly from the calculated dispersions, and they are found to compare well with experiments. It is argued that the parameter dependence of vFv_{\rm F} is quantitatively explained by a simple picture of a renormalized Fermi velocity.Comment: 5 pages, 4 figures, to be published in Phys. Rev. Let

    Endotoxemia and human liver transplantation

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    Ninety liver transplantations were performed in 81 patients. Plasma endotoxin was measured preoperatively, at the end of the anhepatic phase, and on postoperative days 1, 3, and 7. The presence of high endotoxin levels preoperatively and at the end of the anhepatic period was associated with graft failure and a high mortality. Patients with primary nonfunction of their transplants typically had severe endotoxemia. Endotoxemia could be a cause rather than an effect of perioperative complications and graft loss

    The inverse problem of the optimal regulator

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    Inverse problem of optimal regulator for class of systems with integral type performance indice

    Long-term dynamics of Methone, Anthe and Pallene

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    We numerically investigate the long-term dynamics of the Saturn's small satellites Methone (S/2004 S1), Anthe (S/2007 S4) and Pallene (S/2004 S2). In our numerical integrations, these satellites are disturbed by non-spherical shape of Saturn and the six nearest regular satellites. The stability of the small bodies is studied here by analyzing long-term evolution of their orbital elements. We show that long-term evolution of Pallene is dictated by a quasi secular resonance involving the ascending nodes (Ω\Omega) and longitudes of pericentric distances (ϖ\varpi) of Mimas (subscript 1) and Pallene (subscript 2), which critical argument is ϖ2−ϖ1−Ω1+Ω2\varpi_2-\varpi_1-\Omega_1+\Omega_2. Long-term orbital evolution of Methone and Anthe are probably chaotic since: i) their orbits randomly cross the orbit of Mimas in time scales of thousands years); ii) numerical simulations involving both small satellites are strongly affected by small changes in the initial conditions.Comment: 9 pages; 4 figures. Submitted to Proceedings IAU Symposium No. S263, 200

    Unitarity, Crossing Symmetry and Duality of the S-matrix in large N Chern-Simons theories with fundamental matter

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    We present explicit computations and conjectures for 2→22 \to 2 scattering matrices in large NN {\it U(N)U(N)} Chern-Simons theories coupled to fundamental bosonic or fermionic matter to all orders in the 't Hooft coupling expansion. The bosonic and fermionic S-matrices map to each other under the recently conjectured Bose-Fermi duality after a level-rank transposition. The S-matrices presented in this paper may be regarded as relativistic generalization of Aharonov-Bohm scattering. They have unusual structural features: they include a non analytic piece localized on forward scattering, and obey modified crossing symmetry rules. We conjecture that these unusual features are properties of S-matrices in all Chern-Simons matter theories. The S-matrix in one of the exchange channels in our paper has an anyonic character; the parameter map of the conjectured Bose-Fermi duality may be derived by equating the anyonic phase in the bosonic and fermionic theories.Comment: 66 pages+ 45 pages appendices, 20 figures, Few typos corrected and few references adde

    High-Potential C112D/M121X (X = M, E, H, L) Pseudomonas aeruginosa Azurins

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    Site-directed mutagenesis of Pseudomonas aeruginosa azurin C112D at the M121 position has afforded a series of proteins with elevated Cu^(II/I) reduction potentials relative to the CuII aquo ion. The high potential and low axial hyperfine splitting (Cu^(II) electron paramagnetic resonance A|) of the C112D/M121L protein are remarkably similar to features normally associated with type 1 copper centers
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