Deformed Traces and Covariant Quantum Algebras for Quantum Groups GLqp(2)GL_{qp}(2) and GLqp(1∣1)GL_{qp}(1|1)

The q-deformed traces and orbits for the two parametric quantum groups $GL_{qp}(2)$ and $GL_{qp}(1|1)$ are defined. They are subsequently used in the construction of $q$-orbit invariants for these groups. General $qp$-(super)oscillator commutation relations are obtained which remain invariant under the coactions of groups $GL_{qp}(2)$ and $GL_{qp}(1|1)$. The $GL_{qp}(2)$ covariant deformed algebra is deduced in terms of the bilinears of bosonic $qp$-oscillators which turns out to be a central extension of the Witten-type deformation of $sl(2)$ algebra. In the case of the supergroup $GL_{qp}(1|1)$, the corresponding covariant algebras contain $N = 2$ supersymmetric quantum mechanical subalgebras.Comment: LaTeX, 11 pages, a note and a reference added, relevant to hep-th/030912

Universal Continuous Variable Quantum Computation in the Micromaser

We present universal continuous variable quantum computation (CVQC) in the micromaser. With a brief history as motivation we present the background theory and define universal CVQC. We then show how to generate a set of operations in the micromaser which can be used to achieve universal CVQC. It then follows that the micromaser is a potential architecture for CVQC but our proof is easily adaptable to other potential physical systems.Comment: 12 pages, 4 figures, accepted for a presentation at the 9th International Conference on Unconventional Computation (UC10) and LNCS proceedings

Cognitive and social factors in the development of infants with Down syndrome

Infants and young children with Down syndrome can be engaging and affectionate. It seems that in the early months of life their personal relations may be relatively 'spared' the effects of limitations in their capacities for information-processing. Yet how far is this the case as development proceeds? In this paper we discuss some ways in which social and cognitive development interact and mutually influence one another over the first year or so of life, and present preliminary findings from a longitudinal study of infants with and without Down syndrome. The evidence suggests that the development of 'triadic'(person-person-world) social interactions may be affected by limited information-processing capacities in infants with Down syndrome, through a complex socially-mediated developmental trajectory

Formation of Small-Scale Condensations in the Molecular Clouds via Thermal Instability

A systematic study of the linear thermal instability of a self-gravitating magnetic molecular cloud is carried out for the case when the unperturbed background is subject to local expansion or contraction. We consider the ambipolar diffusion, or ion-neutral friction on the perturbed states. In this way, we obtain a non-dimensional characteristic equation that reduces to the prior characteristic equation in the non-gravitating stationary background. By parametric manipulation of this characteristic equation, we conclude that there are, not only oblate condensation forming solutions, but also prolate solutions according to local expansion or contraction of the background. We obtain the conditions for existence of the Field lengths that thermal instability in the molecular clouds can occur. If these conditions establish, small-scale condensations in the form of spherical, oblate, or prolate may be produced via thermal instability.Comment: 16 page, accepted by Ap&S

Parent Skills Training: Expanding School-Based Services for Adolescent Mothers

This article reports the results of a collaborative intervention effort between a teen-parent program and a school of social work Social work faculty and students participated in a program aimed at strengthening parental skills and the utilization of social support among adolescent mothers who were enrolled in a special high school program. The results of this evaluation study point to additional factors, such as empathy training and stress management, which need to be included in a comprehensive service-delivery program for school-age mothers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68359/2/10.1177_104973159200200203.pd

On the peak radio and X-ray emission from neutron star and black hole candidate X-ray transients

We have compiled and analysed reports from the literature of (quasi-)simultaneous observations of X-ray transients at radio and X-ray wavelengths and compared them with each other and with more unusual radio-bright sources such as Cygnus X-3, GRS 1915+105 and Circinus X-1. There exists a significant (>97% likelihood) positive (rank) correlation between the peak X-ray flux P_X and radio flux density P_R for the black hole candidate (BHC) systems, and a marginally significant positive (rank) correlation for the neutron star (NS) systems. This is further evidence for a coupling between accretion and outflows in X-ray binary systems, in this case implying a relation between peak disc-accretion-rate and the number of synchroton-emitting electrons ejected. However, we also show that the distribution of `radio loudness', P_R/P_X, is significantly different for the two samples, in the sense that the BHCs generally have a higher ratio of P_R/P_X. The origin of this discrepancy is uncertain, but probably reflects differences in the energetics and/or radiative efficiency of flows around the neutron stars and black holes; we briefly discuss some of these possibilities. We conclude that these data point to the formation of a mildly relativistic jet whose luminosity is a function of the accretion rate, in the majority, if not all, of X-ray transient outbursts, but whose relation to the observed X-ray emission is dependent on the nature of the accreting compact object. (Abridged).Comment: Accepted for publication in MNRA

Quantum Computing of Quantum Chaos in the Kicked Rotator Model

We investigate a quantum algorithm which simulates efficiently the quantum kicked rotator model, a system which displays rich physical properties, and enables to study problems of quantum chaos, atomic physics and localization of electrons in solids. The effects of errors in gate operations are tested on this algorithm in numerical simulations with up to 20 qubits. In this way various physical quantities are investigated. Some of them, such as second moment of probability distribution and tunneling transitions through invariant curves are shown to be particularly sensitive to errors. However, investigations of the fidelity and Wigner and Husimi distributions show that these physical quantities are robust in presence of imperfections. This implies that the algorithm can simulate the dynamics of quantum chaos in presence of a moderate amount of noise.Comment: research at Quantware MIPS Center http://www.quantware.ups-tlse.fr, revtex 11 pages, 13 figs, 2 figs and discussion adde

Effect of halo modelling on WIMP exclusion limits

WIMP direct detection experiments are just reaching the sensitivity required to detect galactic dark matter in the form of neutralinos. Data from these experiments are usually analysed under the simplifying assumption that the Milky Way halo is an isothermal sphere with maxwellian velocity distribution. Observations and numerical simulations indicate that galaxy halos are in fact triaxial and anisotropic. Furthermore, in the cold dark matter paradigm galactic halos form via the merger of smaller subhalos, and at least some residual substructure survives. We examine the effect of halo modelling on WIMP exclusion limits, taking into account the detector response. Triaxial and anisotropic halo models, with parameters motivated by observations and numerical simulations, lead to significant changes which are different for different experiments, while if the local WIMP distribution is dominated by small scale clumps then the exclusion limits are changed dramatically.Comment: 9 pages, 9 figures, version to appear in Phys. Rev. D, minor change

Bailing Out the Milky Way: Variation in the Properties of Massive Dwarfs Among Galaxy-Sized Systems

Recent kinematical constraints on the internal densities of the Milky Way's dwarf satellites have revealed a discrepancy with the subhalo populations of simulated Galaxy-scale halos in the standard CDM model of hierarchical structure formation. This has been dubbed the "too big to fail" problem, with reference to the improbability of large and invisible companions existing in the Galactic environment. In this paper, we argue that both the Milky Way observations and simulated subhalos are consistent with the predictions of the standard model for structure formation. Specifically, we show that there is significant variation in the properties of subhalos among distinct host halos of fixed mass and suggest that this can reasonably account for the deficit of dense satellites in the Milky Way. We exploit well-tested analytic techniques to predict the properties in a large sample of distinct host halos with a variety of masses spanning the range expected of the Galactic halo. The analytic model produces subhalo populations consistent with both Via Lactea II and Aquarius, and our results suggest that natural variation in subhalo properties suffices to explain the discrepancy between Milky Way satellite kinematics and these numerical simulations. At least ~10% of Milky Way-sized halos host subhalo populations for which there is no "too big to fail" problem, even when the host halo mass is as large as M_host = 10^12.2 h^-1 M_sun. Follow-up studies consisting of high-resolution simulations of a large number of Milky Way-sized hosts are necessary to confirm our predictions. In the absence of such efforts, the "too big to fail" problem does not appear to be a significant challenge to the standard model of hierarchical formation. [abridged]Comment: 12 pages, 3 figures; accepted by JCAP. Replaced with published versio