2,340 research outputs found

    Towards Spinfoam Cosmology

    Get PDF
    We compute the transition amplitude between coherent quantum-states of geometry peaked on homogeneous isotropic metrics. We use the holomorphic representations of loop quantum gravity and the Kaminski-Kisielowski-Lewandowski generalization of the new vertex, and work at first order in the vertex expansion, second order in the graph (multipole) expansion, and first order in 1/volume. We show that the resulting amplitude is in the kernel of a differential operator whose classical limit is the canonical hamiltonian of a Friedmann-Robertson-Walker cosmology. This result is an indication that the dynamics of loop quantum gravity defined by the new vertex yields the Friedmann equation in the appropriate limit.Comment: 8 page

    Analisis Gambaran Peta Perjalanan Pasien di Pelayanan Rawat Jalan RS Kanker “Dharmais” Tahun 2014

    Full text link
    Penelitian ini membahas tentang peta perjalanan pasien di pelayanan rawat jalan RS Kanker “Dharmais” pada tahun 2014. Dalam penelitian ini peneliti berusaha menemukan unit dengan variasi perjalanan pasien tertinggi dan mengidentifikasi faktor-faktor penyebabnya. Penelitian ini adalah penelitian dengan pendekatan kualitatif dan metode cross-sectional. Hasil penelitian ini menemukan bahwa variasi perjalanan pasien tertinggi berada di Instalasi Administrasi Pasien Jaminan (APJ) dengan faktor penyebab antara lain faktor program komputer penunjang, sumber daya manusia, infrastruktur hingga prosedur pelayanan. Penelitian ini juga menemukan bahwa variasi perjalanan pasien dapat mengurangi mutu pelayanan yang diberikan

    Noncommutative geometry of angular momentum space U(su(2))

    Full text link
    We study the standard angular momentum algebra [xi,xj]=iλϵijkxk[x_i,x_j]=i\lambda \epsilon_{ijk}x_k as a noncommutative manifold Rλ3R^3_\lambda. We show that there is a natural 4D differential calculus and obtain its cohomology and Hodge * operator. We solve the spin 0 wave equation and some aspects of the Maxwell or electromagnetic theory including solutions for a uniform electric current density, and we find a natural Dirac operator. We embed Rλ3R^3_\lambda inside a 4D noncommutative spacetime which is the limit q1q\to 1 of q-Minkowski space and show that Rλ3R^3_\lambda has a natural quantum isometry group given by the quantum double D(U(su(2)))D(U(su(2))) as a singular limit of the qq-Lorentz group. We view Rλ3\R^3_\lambda as a collection of all fuzzy spheres taken together. We also analyse the semiclassical limit via minimum uncertainty states j,θ,ϕ>|j,\theta,\phi> approximating classical positions in polar coordinates.Comment: Minor revision to add reference [11]. 37 pages late

    Induced Representations of Quantum Kinematical Algebras and Quantum Mechanics

    Full text link
    Unitary representations of kinematical symmetry groups of quantum systems are fundamental in quantum theory. We propose in this paper its generalization to quantum kinematical groups. Using the method, proposed by us in a recent paper (olmo01), to induce representations of quantum bicrossproduct algebras we construct the representations of the family of standard quantum inhomogeneous algebras Uλ(isoω(2))U_\lambda(iso_{\omega}(2)). This family contains the quantum Euclidean, Galilei and Poincar\'e algebras, all of them in (1+1) dimensions. As byproducts we obtain the actions of these quantum algebras on regular co-spaces that are an algebraic generalization of the homogeneous spaces and qq--Casimir equations which play the role of qq--Schr\"odinger equations.Comment: LaTeX 2e, 20 page

    Generalized exclusion and Hopf algebras

    Full text link
    We propose a generalized oscillator algebra at the roots of unity with generalized exclusion and we investigate the braided Hopf structure. We find that there are two solutions: these are the generalized exclusions of the bosonic and fermionic types. We also discuss the covariance properties of these oscillatorsComment: 10 pages, to appear in J. Phys.

    Differential and Twistor Geometry of the Quantum Hopf Fibration

    Full text link
    We study a quantum version of the SU(2) Hopf fibration S7S4S^7 \to S^4 and its associated twistor geometry. Our quantum sphere Sq7S^7_q arises as the unit sphere inside a q-deformed quaternion space Hq2\mathbb{H}^2_q. The resulting four-sphere Sq4S^4_q is a quantum analogue of the quaternionic projective space HP1\mathbb{HP}^1. The quantum fibration is endowed with compatible non-universal differential calculi. By investigating the quantum symmetries of the fibration, we obtain the geometry of the corresponding twistor space CPq3\mathbb{CP}^3_q and use it to study a system of anti-self-duality equations on Sq4S^4_q, for which we find an `instanton' solution coming from the natural projection defining the tautological bundle over Sq4S^4_q.Comment: v2: 38 pages; completely rewritten. The crucial difference with respect to the first version is that in the present one the quantum four-sphere, the base space of the fibration, is NOT a quantum homogeneous space. This has important consequences and led to very drastic changes to the paper. To appear in CM

    An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

    Get PDF
    In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna

    Representations of Quantum Bicrossproduct Algebras

    Full text link
    We present a method to construct induced representations of quantum algebras having the structure of bicrossproduct. We apply this procedure to some quantum kinematical algebras in (1+1)--dimensions with this kind of structure: null-plane quantum Poincare algebra, non-standard quantum Galilei algebra and quantum kappa Galilei algebra.Comment: LaTeX 2e, 35 page

    Physics of Quantum Relativity through a Linear Realization

    Full text link
    The idea of quantum relativity as a generalized, or rather deformed, version of Einstein (special) relativity has been taking shape in recent years. Following the perspective of deformations, while staying within the framework of Lie algebra, we implement explicitly a simple linear realization of the relativity symmetry, and explore systematically the resulting physical interpretations. Some suggestions we make may sound radical, but are arguably natural within the context of our formulation. Our work may provide a new perspective on the subject matter, complementary to the previous approach(es), and may lead to a better understanding of the physics.Comment: 27 pages in Revtex, no figure; proof-edited version to appear in Phys.Rev.
    corecore