51 research outputs found

    Nonlinear collective nuclear motion

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    For each real number Λ\Lambda a Lie algebra of nonlinear vector fields on three dimensional Euclidean space is reported. Although each algebra is mathematically isomorphic to gl(3,R)gl(3,{\bf R}), only the Λ=0\Lambda=0 vector fields correspond to the usual generators of the general linear group. The Λ<0\Lambda < 0 vector fields integrate to a nonstandard action of the general linear group; the Λ>0\Lambda >0 case integrates to a local Lie semigroup. For each Λ\Lambda, a family of surfaces is identified that is invariant with respect to the group or semigroup action. For positive Λ\Lambda the surfaces describe fissioning nuclei with a neck, while negative Λ\Lambda surfaces correspond to exotic bubble nuclei. Collective models for neck and bubble nuclei are given by irreducible unitary representations of a fifteen dimensional semidirect sum spectrum generating algebra gcm(3)gcm(3) spanned by its nonlinear gl(3,R)gl(3,{\bf R}) subalgebra plus an abelian nonlinear inertia tensor subalgebra.Comment: 13 pages plus two figures(available by fax from authors by request

    Algebraic nonlinear collective motion

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    Finite-dimensional Lie algebras of vector fields determine geometrical collective models in quantum and classical physics. Every set of vector fields on Euclidean space that generates the Lie algebra sl(3, R) and contains the angular momentum algebra so(3) is determined. The subset of divergence-free sl(3, R) vector fields is proven to be indexed by a real number Λ\Lambda. The Λ=0\Lambda=0 solution is the linear representation that corresponds to the Riemann ellipsoidal model. The nonlinear group action on Euclidean space transforms a certain family of deformed droplets among themselves. For positive Λ\Lambda, the droplets have a neck that becomes more pronounced as Λ\Lambda increases; for negative Λ\Lambda, the droplets contain a spherical bubble of radius ∣Λ∣1/3|\Lambda|^{{1/3}}. The nonlinear vector field algebra is extended to the nonlinear general collective motion algebra gcm(3) which includes the inertia tensor. The quantum algebraic models of nonlinear nuclear collective motion are given by irreducible unitary representations of the nonlinear gcm(3) Lie algebra. These representations model fissioning isotopes (Λ>0\Lambda>0) and bubble and two-fluid nuclei (Λ<0\Lambda<0).Comment: 32pages, 4 figures not include

    Global Time Distribution via Satellite-Based Sources of Entangled Photons

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    We propose a satellite-based scheme to perform clock synchronization between ground stations spread across the globe using quantum resources. We refer to this as a quantum clock synchronization (QCS) network. Through detailed numerical simulations, we assess the feasibility and capabilities of a near-term implementation of this scheme. We consider a small constellation of nanosatellites equipped only with modest resources. These include quantum devices such as spontaneous parametric down conversion (SPDC) sources, avalanche photo-detectors (APDs), and moderately stable on-board clocks such as chip scale atomic clocks (CSACs). In our simulations, the various performance parameters describing the hardware have been chosen such that they are either already commercially available, or require only moderate advances. We conclude that with such a scheme establishing a global network of ground based clocks synchronized to sub-nanosecond level (up to a few picoseconds) of precision, would be feasible. Such QCS satellite constellations would form the infrastructure for a future quantum network, able to serve as a globally accessible entanglement resource. At the same time, our clock synchronization protocol, provides the sub-nanosecond level synchronization required for many quantum networking protocols, and thus, can be seen as adding an extra layer of utility to quantum technologies in the space domain designed for other purposes.Comment: 20 pages, 12 figures and 6 tables. Comments are welcom
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