2,805 research outputs found

    Coupling of Linearized Gravity to Nonrelativistic Test Particles: Dynamics in the General Laboratory Frame

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    The coupling of gravity to matter is explored in the linearized gravity limit. The usual derivation of gravity-matter couplings within the quantum-field-theoretic framework is reviewed. A number of inconsistencies between this derivation of the couplings, and the known results of tidal effects on test particles according to classical general relativity are pointed out. As a step towards resolving these inconsistencies, a General Laboratory Frame fixed on the worldline of an observer is constructed. In this frame, the dynamics of nonrelativistic test particles in the linearized gravity limit is studied, and their Hamiltonian dynamics is derived. It is shown that for stationary metrics this Hamiltonian reduces to the usual Hamiltonian for nonrelativistic particles undergoing geodesic motion. For nonstationary metrics with long-wavelength gravitational waves (GWs) present, it reduces to the Hamiltonian for a nonrelativistic particle undergoing geodesic \textit{deviation} motion. Arbitrary-wavelength GWs couple to the test particle through a vector-potential-like field NaN_a, the net result of the tidal forces that the GW induces in the system, namely, a local velocity field on the system induced by tidal effects as seen by an observer in the general laboratory frame. Effective electric and magnetic fields, which are related to the electric and magnetic parts of the Weyl tensor, are constructed from NaN_a that obey equations of the same form as Maxwell's equations . A gedankin gravitational Aharonov-Bohm-type experiment using NaN_a to measure the interference of quantum test particles is presented.Comment: 38 pages, 7 figures, written in ReVTeX. To appear in Physical Review D. Galley proofs corrections adde

    John Y. Templeton III: Pioneer of modern cardiothoracic surgery.

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    John Young Templeton III was born in 1917 in Portsmouth, Virginia, and graduated from Jefferson Medical College in 1941. He completed his residency training under Dr. John H. Gibbon, Jr., and was the first resident who worked on Gibbon\u27s heart-lung machine. After his training, he remained at Jefferson as an American Cancer Society fellow and Damon Runyon fellow and went on to become the fourth Samuel D. Gross Professor and Chair of the Department of Surgery in 1967. Dr. Templeton was the recipient of numerous grants and published over 80 papers in the field of cardiothoracic surgery. As a teacher and mentor, he was a beloved figure who placed great faith in his residents. He participated in over 60 professional societies, serving as president to many such as the Philadelphia Academy of Surgery and the Pennsylvania Association of Thoracic Surgery. He was also recognized through his many awards, in particular the John Y. Templeton III lectureship established in 1980 at Jefferson of whom Denton Cooley was the first lecturer. Dr. Templeton retired from practice in 1987. He is forever remembered as an important model of a modern surgeon evident in numerous academic achievements, the admiration and affection of his trainees, and the lives of patients that he had touched

    Quaternion Gravi-Electromagnetism

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    Defining the generalized charge, potential, current and generalized fields as complex quantities where real and imaginary parts represent gravitation and electromagnetism respectively, corresponding field equation, equation of motion and other quantum equations are derived in manifestly covariant manner. It has been shown that the field equations are invariant under Lorentz as well as duality transformations. It has been shown that the quaternionic formulation presented here remains invariant under quaternion transformations.Comment: Key Words: Quaternion, dyons, gravito-dyons, gravi-electromagnetism. PACS No.: 04.90. +e ; 14.80. H

    On the oscillation of solutions and existence of positive solutions of neutral difference equations

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    AbstractWe obtain sufficient conditions for the oscillation of all solutions and existence of positive solutions of the neutral difference equation Δ(xn + cxn − m) + pnxn − k = 0, n = 0, 1, 2, …, where c and pn are real numbers, m and k are integers, and pn, m and k are nonnegative

    Calculus of Tangent Sets and Derivatives of Set Valued Maps under Metric Subregularity Conditions

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    In this paper we intend to give some calculus rules for tangent sets in the sense of Bouligand and Ursescu, as well as for corresponding derivatives of set-valued maps. Both first and second order objects are envisaged and the assumptions we impose in order to get the calculus are in terms of metric subregularity of the assembly of the initial data. This approach is different from those used in alternative recent papers in literature and allows us to avoid compactness conditions. A special attention is paid for the case of perturbation set-valued maps which appear naturally in optimization problems.Comment: 17 page

    Synergistic Cytotoxicity Of Clofarabine, Fludarabine And Busulfan: Relevance To Myeloablative Therapy

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    Two-step deterministic remote preparation of an arbitrary quantum state in the whole Hilbert space

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    We present a two-step exact remote state preparation protocol of an arbitrary qubit with the aid of a three-particle Greenberger-Horne-Zeilinger state. Generalization of this protocol for higher-dimensional Hilbert space systems among three parties is also given. We show that only single-particle von Neumann measurement, local operation and classical communication are necessary. Moreover, since the overall information of the quantum state can be divided into two different parts, which may be at different locations, this protocol may be useful in the quantum information field.Comment: 5 page

    The strangeness form factors of the proton

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    The present empirical information on the strangeness form factors indicates that the corresponding uudssˉuuds\bar s component in the proton is such that the uudsuuds subsystem has the flavor spin symmetry [4]FS[22]F[22]S[4]_{FS}[22]_F[22]_S and mixed orbital symmetry [31]X[31]_X. This uudssˉuuds\bar s configuration leads to the empirical signs of all the form factors GEsG_E^s, GMsG_M^s and GAsG_A^s. An analysis with simple quark model wave functions for the preferred configuration shows that the qualitative features of the empirical strangeness form factors may be described with a ∼\sim 15% admixture of uudssˉuuds\bar s with a compact wave function in the proton. Transition matrix elements between the uuduud and the uudssˉuuds\bar s components give significant contributions
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