23,637 research outputs found
Long Range Scattering and Modified Wave Operators for some Hartree Type Equations
We study the theory of scattering for a class of Hartree type equations with
long range interactions in space dimension n > 2, including Hartree equations
with potential V(x) = lambda |x|^{- gamma} with gamma < 1. For 1/2 < gamma < 1
we prove the existence of modified wave operators with no size restriction on
the data and we determine the asymptotic behaviour in time of solutions in the
range of the wave operators.Comment: TeX, 89 pages, available http://qcd.th.u-psud.f
The Mixed State of Charge-Density-Wave in a Ring-Shaped Single Crystals
Charge-density-wave (CDW) phase transition in a ring-shaped crystals,
recently synthesized by Tanda et al. [Nature, 417, 397 (2002)], is studied
based on a mean-field-approximation of Ginzburg-Landau free energy. It is shown
that in a ring-shaped crystals CDW undergoes frustration due to the curvature
(bending) of the ring (geometrical frustration) and, thus, forms a mixed state
analogous to what a type-II superconductor forms under a magnetic field. We
discuss the nature of the phase transition in the ring-CDW in relation to
recent experiments.Comment: 6 pages, 4 figure
Parental Altruism and Inter Vivos Transfers: Theory and Evidence
This paper uses PSID data on the extended family to test whether inter vivos transfers from parents to children are motivated by altruism. Specifically, the paper tests whether an increase by one dollar in the income of parents actively making transfers to a child coupled with a one dollar reduction in that child's income results in the parents increasing their transfer to the child by one dollar. This restriction on parental and child transfer-income derivatives is derived for the standard altruism model augmented to include uncertain and liquidity constraints. These additional elements pin down the timing of inter vivos transfers. The paper's method of estimating income-transfer derivatives takes into account unobserved heterogeneity across families in the degree of altruism. The findings strongly reject the altruism hypothesis. Redistributing one dollar from a recipient child to donor parents leads to less than a 13 cent increase in the parents' transfer to the child -- far less than the one dollar increase implied by altruism.
Noisy quantum Monty Hall game
The influence of spontaneous emission channel and generalized Pauli channel
on quantum Monty Hall Game is analysed. The scheme of Flittney and Abbott is
reformulated using the formalism of density matrices. Optimal classical
strategies for given quantum strategies are found. The whole presented scheme
illustrates how quantum noise may change the odds of a zero-sum game.Comment: 10 pages, 3 figure
Asymptotic estimation theory for a finite dimensional pure state model
The optimization of measurement for n samples of pure sates are studied. The
error of the optimal measurement for n samples is asymptotically compared with
the one of the maximum likelihood estimators from n data given by the optimal
measurement for one sample.Comment: LaTeX, 23 pages, Doctoral Thesi
Two quantum analogues of Fisher information from a large deviation viewpoint of quantum estimation
We discuss two quantum analogues of Fisher information, symmetric logarithmic
derivative (SLD) Fisher information and Kubo-Mori-Bogoljubov (KMB) Fisher
information from a large deviation viewpoint of quantum estimation and prove
that the former gives the true bound and the latter gives the bound of
consistent superefficient estimators. In another comparison, it is shown that
the difference between them is characterized by the change of the order of
limits.Comment: LaTeX with iopart.cls, iopart12.clo, iopams.st
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