547 research outputs found

    Trajectories in the Context of the Quantum Newton's Law

    Full text link
    In this paper, we apply the one dimensional quantum law of motion, that we recently formulated in the context of the trajectory representation of quantum mechanics, to the constant potential, the linear potential and the harmonic oscillator. In the classically allowed regions, we show that to each classical trajectory there is a family of quantum trajectories which all pass through some points constituting nodes and belonging to the classical trajectory. We also discuss the generalization to any potential and give a new definition for de Broglie's wavelength in such a way as to link it with the length separating adjacent nodes. In particular, we show how quantum trajectories have as a limit when 0\hbar \to 0 the classical ones. In the classically forbidden regions, the nodal structure of the trajectories is lost and the particle velocity rapidly diverges.Comment: 17 pages, LateX, 6 eps figures, minor modifications, Title changed, to appear in Physica Script

    On the linearization of the generalized Ermakov systems

    Full text link
    A linearization procedure is proposed for Ermakov systems with frequency depending on dynamic variables. The procedure applies to a wide class of generalized Ermakov systems which are linearizable in a manner similar to that applicable to usual Ermakov systems. The Kepler--Ermakov systems belong into this category but others, more generic, systems are also included

    Unitary relations in time-dependent harmonic oscillators

    Get PDF
    For a harmonic oscillator with time-dependent (positive) mass and frequency, an unitary operator is shown to transform the quantum states of the system to those of a harmonic oscillator system of unit mass and time-dependent frequency, as well as operators. For a driven harmonic oscillator, it is also shown that, there are unitary transformations which give the driven system from the system of same mass and frequency without driving force. The transformation for a driven oscillator depends on the solution of classical equation of motion of the driven system. These transformations, thus, give a simple way of finding exact wave functions of a driven harmonic oscillator system, provided the quantum states of the corresponding system of unit mass are given.Comment: Submitted to J. Phys.

    The Equivalence Postulate of Quantum Mechanics

    Get PDF
    The Equivalence Principle (EP), stating that all physical systems are connected by a coordinate transformation to the free one with vanishing energy, univocally leads to the Quantum Stationary HJ Equation (QSHJE). Trajectories depend on the Planck length through hidden variables which arise as initial conditions. The formulation has manifest p-q duality, a consequence of the involutive nature of the Legendre transform and of its recently observed relation with second-order linear differential equations. This reflects in an intrinsic psi^D-psi duality between linearly independent solutions of the Schroedinger equation. Unlike Bohm's theory, there is a non-trivial action even for bound states. No use of any axiomatic interpretation of the wave-function is made. Tunnelling is a direct consequence of the quantum potential which differs from the usual one and plays the role of particle's self-energy. The QSHJE is defined only if the ratio psi^D/psi is a local self-homeomorphism of the extended real line. This is an important feature as the L^2 condition, which in the usual formulation is a consequence of the axiomatic interpretation of the wave-function, directly follows as a basic theorem which only uses the geometrical gluing conditions of psi^D/psi at q=\pm\infty as implied by the EP. As a result, the EP itself implies a dynamical equation that does not require any further assumption and reproduces both tunnelling and energy quantization. Several features of the formulation show how the Copenhagen interpretation hides the underlying nature of QM. Finally, the non-stationary higher dimensional quantum HJ equation and the relativistic extension are derived.Comment: 1+3+140 pages, LaTeX. Invariance of the wave-function under the action of SL(2,R) subgroups acting on the reduced action explicitly reveals that the wave-function describes only equivalence classes of Planck length deterministic physics. New derivation of the Schwarzian derivative from the cocycle condition. "Legendre brackets" introduced to further make "Legendre duality" manifest. Introduction now contains examples and provides a short pedagogical review. Clarifications, conclusions, ackn. and references adde

    Time-Dependent Invariants for Dirac Equation and Newton-Wigner Position Operator

    Get PDF
    For Dirac equation, operator-invariants containing explicit time-dependence in parallel to known time-dependent invariants of nonrelativistic Schr\"odinger equation are introduced and discussed. As an example, a free Dirac particle is considered and new invariants are constructed for it. The integral of motion, which is initial Newton-Wigner position operator, is obtained explicitly for a free Dirac particle. For such particle with kick modeled by delta-function of time, the time-depending integral, which has physical meaning of initial momentum, is found.Comment: LATEX,21 pages,submitted to Physica Script

    Management accounting of agricultural production: improving planning and standardization of costs in the management information system

    Get PDF
    The problems of organizing effective management accounting of agricultural production through the widespread use of economic methods, both production management and accounting and management methods and the development of their information functions, are very relevant and necessary. Management accounting in modern times is a universal integrated mechanism for the accounting and management activities of an agricultural organization. The management accounting information system should be oriented towards solving complex issues and making managerial decisions quickly. The purpose of the study is the rationale for rationing, planning and management accounting of costs, their control and analysis of production results in the agricultural management information system. The subject of the study is management accounting, while principles are formulated and new methods for rationing labor, material and biological costs of agricultural production are proposed. A unified nomenclature of cost items has been developed for planning, managerial accounting, analysis and control, both for individual production, accounting and planning objects, as well as for self-supporting units (responsibility centers) and the organization as a whole. For the organization of rationing, planning and management accounting of production costs, the sequence of implementation of special procedures is defined, a unified nomenclature of cost items is developed based on the basic conditions of requirements, which include classification attributes, degree of cost participation in the creation of new products, cost control by hierarchical levels of management. It is concluded that by comparing the actual and planned costs for the production of a particular object of planning and accounting, it is possible to analyze their cause and effect deviations, deviations of the actual marginal income and operating profit of the production of these products from their normative values ​​by changing each specific cost item

    Lie symmetries for two-dimensional charged particle motion

    Full text link
    We find the Lie point symmetries for non-relativistic two-dimensional charged particle motion. These symmetries comprise a quasi-invariance transformation, a time-dependent rotation, a time-dependent spatial translation and a dilation. The associated electromagnetic fields satisfy a system of first-order linear partial differential equations. This system is solved exactly, yielding four classes of electromagnetic fields compatible with Lie point symmetries

    Schemes of implementation in NMR of quantum processors and Deutsch-Jozsa algorithm by using virtual spin representation

    Full text link
    Schemes of experimental realization of the main two qubit processors for quantum computers and Deutsch-Jozsa algorithm are derived in virtual spin representation. The results are applicable for every four quantum states allowing the required properties for quantum processor implementation if for qubit encoding virtual spin representation is used. Four dimensional Hilbert space of nuclear spin 3/2 is considered in details for this aimComment: 15 pages, 3 figure

    Estimating Temperature Fluctuations in the Early Universe

    Full text link
    A lagrangian for the kk- essence field is constructed for a constant scalar potential and its form determined when the scale factor was very small compared to the present epoch but very large compared to the inflationary epoch. This means that one is already in an expanding and flat universe. The form is similar to that of an oscillator with time-dependent frequency. Expansion is naturally built into the theory with the existence of growing classical solutions of the scale factor. The formalism allows one to estimate fluctuations of the temperature of the background radiation in these early stages (compared to the present epoch) of the universe. If the temperature at time tat_{a} is TaT_{a} and at time tbt_{b} the temperature is TbT_{b} (tb>tat_{b}>t_{a}), then for small times, the probability for the logarithm of inverse temperature evolution can be estimated to be given by P(b,a)=ln (1Tb),tbln (1Ta),ta2P(b,a)= |\langle ln~({1\over T_{b}}),t_{b}| ln~({1\over T_{a}}),t_{a}\rangle|^{2} (3mPl2π2(tbta)3)(ln Ta)2(ln Tb)2(13γ(ta+tb))\approx\biggl({3m_{\mathrm Pl}^{2}\over \pi^{2} (t_{b}-t_{a})^{3}}\biggr) (ln~ T_{a})^{2}(ln~T_{b})^{2}\biggl(1 - 3\gamma (t_{a} + t_{b})\biggr) where 0<γ<10<\gamma<1, mPlm_{\mathrm Pl} is the Planck mass and Planck's constant and the speed of light has been put equal to unity. There is the further possibility that a single scalar field may suffice for an inflationary scenario as well as the dark matter and dark energy realms.Comment: 8 pages, Revtex, title,abstract and format changed for journal publication,no change in basic results, clarifications and a figure added. Keywords: physics of the early universe,inflation, dark matter theory, dark energy theory. PACS: 95.35.+d ; 95.36.+x ; 98.80.Cq ; 98.80.-
    corecore