116 research outputs found

    Thermodynamics via Creation from Nothing: Limiting the Cosmological Constant Landscape

    Get PDF
    The creation of a quantum Universe is described by a {\em density matrix} which yields an ensemble of universes with the cosmological constant limited to a bounded range ΛminΛΛmax\Lambda_{\rm min}\leq \Lambda \leq \Lambda_{\rm max}. The domain Λ<Λmin\Lambda<\Lambda_{\rm min} is ruled out by a cosmological bootstrap requirement (the self-consistent back reaction of hot matter). The upper cutoff results from the quantum effects of vacuum energy and the conformal anomaly mediated by a special ghost-avoidance renormalization. The cutoff Λmax\Lambda_{\rm max} establishes a new quantum scale -- the accumulation point of an infinite sequence of garland-type instantons. The dependence of the cosmological constant range on particle phenomenology suggests a possible dynamical selection mechanism for the landscape of string vacua.Comment: RevTex, 4 pages, 4 figure

    Strain-Compensated AlInGaAs-GaAsP Superlattices for Highly-Polarized Electron Emission

    Full text link
    Spin-polarized electron emission from the first superlattice photocathodes developed with strain compensation is investigated. An opposite strain in the quantum well and barrier layers is complished using an InAlGaAs/GaAsP superlattice structure. The measured values of maximum polarization and quantum yield for the structure with a 0.18 um-thick working layer are close to the best results reported for any strained superlattice photocathode structure, demonstrating the high potential of strain compensation for future photocathode applications. An analysis of the photoemission spectra is used to estimate the parameters responsible for the polarization losses.Comment: 10 pages, 2 figure

    Phase boundary texturing influence on laminated compound durability under local thermal effect

    Get PDF
    Destruction process modeling has been conducted for a laminated material under a local pointed thermal effect. Temperature field dependence on the coating surface texturing parameters has been studied. A mathematical model of the load distribution in the laminated material with wavy coating surface texturing under thermal effect is presented

    Paraneoplastic syndrome in urothelial carcinoma of the kidney: difficulty in diagnosis and deterioration in prognosis

    Get PDF
    Paraneoplastic syndrome is not a common concomitance of urothelial tumors. The literature describes a few tens of clinical cases in which urothelial cancer has become a cause of marked nonspecific tumor-associated reactions, associated with the presence of the tumor. Bladder tumors are at stake in all cases. The given clinical observation describes paraneoplastic manifestations in high-grade urothelial carcinoma of the kidney. It demonstrates difficulties in differential diagnosis and gives a retrospective estimate of diagnostic and therapeutic tactics

    Cosmological Landscape From Nothing: Some Like It Hot

    Get PDF
    We suggest a novel picture of the quantum Universe -- its creation is described by the {\em density matrix} defined by the Euclidean path integral. This yields an ensemble of universes -- a cosmological landscape -- in a mixed state which is shown to be dynamically more preferable than the pure quantum state of the Hartle-Hawking type. The latter is dynamically suppressed by the infinitely large positive action of its instanton, generated by the conformal anomaly of quantum fields within the cosmological bootstrap (the self-consistent back reaction of hot matter). This bootstrap suggests a solution to the problem of boundedness of the on-shell cosmological action and eliminates the infrared catastrophe of small cosmological constant in Euclidean quantum gravity. The cosmological landscape turns out to be limited to a bounded range of the cosmological constant ΛminΛΛmax\Lambda_{\rm min}\leq \Lambda \leq \Lambda_{\rm max}. The domain Λ<Λmin\Lambda<\Lambda_{\rm min} is ruled out by the back reaction effect which we analyze by solving effective Euclidean equations of motion. The upper cutoff is enforced by the quantum effects of vacuum energy and the conformal anomaly mediated by a special ghost-avoidance renormalization of the effective action. They establish a new quantum scale Λmax\Lambda_{\rm max} which is determined by the coefficient of the topological Gauss-Bonnet term in the conformal anomaly. This scale is realized as the upper bound -- the limiting point of an infinite sequence of garland-type instantons which constitute the full cosmological landscape. The dependence of the cosmological constant range on particle phenomenology suggests a possible dynamical selection mechanism for the landscape of string vacua.Comment: Final version, to appear in JCA

    Rotational Doppler shift of the phase-conjugated photon

    Full text link
    The rotational Doppler shift of a photon with orbital angular momentum ±\pm \ell \hbar is shown to be an even multiple of the angular frequency Ω\Omega of the reference frame rotation when photon is reflected from the phase-conjugating mirror. We consider the one-arm phase-conjugating interferometer which contains NN Dove prisms or other angular momentum altering elements rotating in opposite directions. When such interferometer is placed in the rotating vehicle the δω=4(N+1/2)Ω\delta \omega=4 (N+1/2) \ell \cdot \Omega rotational Doppler shift appears and rotation of the helical interference pattern with angular frequency δω/2\delta \omega /{2 \ell} occurs. The accumulation of angular Doppler shift via successive passage through the NN image-inverting prisms is due to the phase conjugation, for conventional parabolic retroreflector the accumulation is absent. The features of such a vortex phase conjugating interferometry at the single photon level are discussed.Comment: 6 pages, 3 figures, submitted to referred journa

    РЕАКЦІЯ ВОДИ НА ПРИРОДНІ ТА ШТУЧНІ ФІЗИЧНІ ФАКТОРИ НАДНИЗЬКОЇ ІНТЕНСИВНОСТІ

    Get PDF
    The researching of the water reaction was done - the changing of its spontaneous oscillation by the influence of the external factors, which have the low intensity. It is shown that the state of the water depends of the Moon phases and the influence of the electromagnetic field which has nonthermal intensity.Проведено исследование реакции воды - изменение ее спонтанных колебаний при влиянии внешних факторов крайне низкой интенсивности. Показано, что состояния воды могут зависеть от изменений фаз Луны, а также от воздействия электромагнитных полей нетепловой интенсивности.Проведено дослідження реакції води - зміна її спонтанних коливань при впливі зовнішніх факторів наднизької інтенсивності. Показано, що стани води можуть залежати від фаз Місяця, а також від впливу електромагнітних полів нетеплової інтенсивності
    corecore