8,871 research outputs found
Weak Energy: Form and Function
The equation of motion for a time-independent weak value of a quantum
mechanical observable contains a complex valued energy factor - the weak energy
of evolution. This quantity is defined by the dynamics of the pre-selected and
post-selected states which specify the observable's weak value. It is shown
that this energy: (i) is manifested as dynamical and geometric phases that
govern the evolution of the weak value during the measurement process; (ii)
satisfies the Euler-Lagrange equations when expressed in terms of Pancharatnam
(P) phase and Fubini-Study (FS) metric distance; (iii) provides for a PFS
stationary action principle for quantum state evolution; (iv) time translates
correlation amplitudes; (v) generalizes the temporal persistence of state
normalization; and (vi) obeys a time-energy uncertainty relation. A similar
complex valued quantity - the pointed weak energy of an evolving state - is
also defined and several of its properties in PFS-coordinates are discussed. It
is shown that the imaginary part of the pointed weak energy governs the state's
survival probability and its real part is - to within a sign - the
Mukunda-Simon geometric phase for arbitrary evolutions or the Aharonov-Anandan
(AA) phase for cyclic evolutions. Pointed weak energy gauge transformations and
the PFS 1-form are discussed and the relationship between the PFS 1-form and
the AA connection 1-form is established.Comment: To appear in "Quantum Theory: A Two-Time Success Story"; Yakir
Aharonov Festschrif
Variance Control in Weak Value Measurement Pointers
The variance of an arbitrary pointer observable is considered for the general
case that a complex weak value is measured using a complex valued pointer
state. For the typical cases where the pointer observable is either its
position or momentum, the associated expressions for the pointer's variance
after the measurement contain a term proportional to the product of the weak
value's imaginary part with the rate of change of the third central moment of
position relative to the initial pointer state just prior to the time of the
measurement interaction when position is the observable - or with the initial
pointer state's third central moment of momentum when momentum is the
observable. These terms provide a means for controlling pointer position and
momentum variance and identify control conditions which - when satisfied - can
yield variances that are smaller after the measurement than they were before
the measurement. Measurement sensitivities which are useful for estimating weak
value measurement accuracies are also briefly discussed.Comment: submitted to Phys Rev
Polar orbit electrostatic charging of objects in shuttle wake
A survey of DMSP data has uncovered several cases where precipitating auroral electron fluxes are both sufficiently intense and energetic to charge spacecraft materials such as teflon to very large potentials in the absence of ambient ion currents. Analytical bounds are provided which show that these measured environments can cause surface potentials in excess of several hundred volts to develop on objects in the orbiter wake for particular vehicle orientations
A feasibility study: California Department of Forestry and Fire Protection utilization of infrared technologies for wildland fire suppression and management
NASA's JPL has completed a feasibility study using infrared technologies for wildland fire suppression and management. The study surveyed user needs, examined available technologies, matched the user needs with technologies, and defined an integrated infrared wildland fire mapping concept system configuration. System component trade-offs were presented for evaluation in the concept system configuration. The economic benefits of using infrared technologies in fire suppression and management were examined. Follow-on concept system configuration development and implementation were proposed
Extracting joint weak values with local, single-particle measurements
Weak measurement is a new technique which allows one to describe the
evolution of postselected quantum systems. It appears to be useful for
resolving a variety of thorny quantum paradoxes, particularly when used to
study properties of pairs of particles. Unfortunately, such nonlocal or joint
observables often prove difficult to measure weakly in practice (for instance,
in optics -- a common testing ground for this technique -- strong photon-photon
interactions would be needed). Here we derive a general, experimentally
feasible, method for extracting these values from correlations between
single-particle observables.Comment: 6 page
Advanced Transport Operating System (ATOPS) control display unit software description
The software created for the Control Display Units (CDUs), used for the Advanced Transport Operating Systems (ATOPS) project, on the Transport Systems Research Vehicle (TSRV) is described. Module descriptions are presented in a standardized format which contains module purpose, calling sequence, a detailed description, and global references. The global reference section includes subroutines, functions, and common variables referenced by a particular module. The CDUs, one for the pilot and one for the copilot, are used for flight management purposes. Operations performed with the CDU affects the aircraft's guidance, navigation, and display software
Perturbation analysis of trapped-particle dynamics in axisymmetric dipole geometry
The perturbation analysis of the bounce action-angle coordinates
for charged particles trapped in an axisymmetric dipole magnetic field is
presented. First, the lowest-order bounce action-angle coordinates are derived
for deeply-trapped particles in the harmonic-oscillator approximation. Next,
the Lie-transform perturbation method is used to derive higher-order anharmonic
action-angle corrections. Explicit expressions (with anharmonic corrections)
for the canonical parallel coordinates and are
presented, which satisfy the canonical identity . Lastly, analytical expressions for the bounce and drift frequencies
(which include anharmonic corrections) yield excellent agreement with exact
numerical results.Comment: 16 pages, 3 figure
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