3,313 research outputs found

    Cross-Cultural Emotion Recognition of Angry and Happy Face between China and Indonesia samples

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    Face emotion recognition have an important ability in surviving in social relations and have been a nosology of anxiety disorder The aim of this study is to test the influence of' culture between Indonesia and China sample. Participants of this study are 40 student from both countries. Two experiments have been conducted to measure the latency and the score of correct answer in recognizing of happy, neutral and angry face. This reserach found that China samples are significant more, faster andhigher score in angry face recognition

    Collective Dynamics of One-Dimensional Charge Density Waves

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    The effect of disorder on the static and dynamic behaviour of one-dimensional charge density waves at low temperatures is studied by analytical and numerical approaches. In the low temperature region the spatial behaviour of the phase-phase correlation function is dominated by disorder but the roughness exponent remains the same as in the pure case. Contrary to high dimensional systems the dependence of the creep velocity on the electric field is described by an analytic function.Comment: 4 pages, 4 figure

    On Aharonov-Casher bound states

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    In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the E\boldsymbol{\nabla}\cdot\mathbf{E} term cannot be neglected in the Hamiltonian if the spin of particle is considered. This term leads to the existence of a singular potential at the origin. By modeling the problem by boundary conditions at the origin which arises by the self-adjoint extension of the Hamiltonian, we derive for the first time an expression for the bound state energy of the Aharonov-Casher problem. As an application, we consider the Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the expression for the harmonic oscillator energies and compare it with the expression obtained in the case without singularity. At the end, an approach for determination of the self-adjoint extension parameter is given. In our approach, the parameter is obtained essentially in terms of physics of the problem.Comment: 11 pages, matches published versio

    Larmor precession and tunneling time of a relativistic neutral spinning particle through an arbitrary potential barrier

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    The Larmor precession of a relativistic neutral spin-1/2 particle in a uniform constant magnetic field confined to the region of a one-dimensional arbitrary potential barrier is investigated. The spin precession serves as a clock to measure the time spent by a quantum particle traversing a potential barrier. With the help of general spin coherent state it is explicitly shown that the precession time is equal to the dwell time.Comment: 10 pages, 1 figure. To be published in Phys. Rev. A (01 February 2002

    Scaling of Aharonov-Bohm couplings and the dynamical vacuum in gauge theories

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    Recent results on the vacuum polarization induced by a thin string of magnetic flux lead us to suggest an analogue of the Copenhagen `flux spaghetti' QCD vacuum as a possible mechanism for avoiding the divergence of perturbative QED, thus permitting consistent completion of the full, nonperturbative theory. The mechanism appears to operate for spinor, but not scalar, QED.Comment: 11 pages, ITP-SB-92-40, (major conceptual evolution from original

    De Sitter Holography with a Finite Number of States

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    We investigate the possibility that, in a combined theory of quantum mechanics and gravity, de Sitter space is described by finitely many states. The notion of observer complementarity, which states that each observer has complete but complementary information, implies that, for a single observer, the complete Hilbert space describes one side of the horizon. Observer complementarity is implemented by identifying antipodal states with outgoing states. The de Sitter group acts on S-matrix elements. Despite the fact that the de Sitter group has no nontrivial finite-dimensional unitary representations, we show that it is possible to construct an S-matrix that is finite-dimensional, unitary, and de Sitter-invariant. We present a class of examples that realize this idea holographically in terms of spinor fields on the boundary sphere. The finite dimensionality is due to Fermi statistics and an `exclusion principle' that truncates the orthonormal basis in which the spinor fields can be expanded.Comment: 23 pages, 1 eps figure, LaTe

    The topological AC effect on noncommutative phase space

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    The Aharonov-Casher (AC) effect in non-commutative(NC) quantum mechanics is studied. Instead of using the star product method, we use a generalization of Bopp's shift method. After solving the Dirac equations both on noncommutative space and noncommutative phase space by the new method, we obtain the corrections to AC phase on NC space and NC phase space respectively.Comment: 8 pages, Latex fil

    Uniqueness and Nondegeneracy of Ground States for (Δ)sQ+QQα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1} = 0 in R\mathbb{R}

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    We prove uniqueness of ground state solutions Q=Q(x)0Q = Q(|x|) \geq 0 for the nonlinear equation (Δ)sQ+QQα+1=0(-\Delta)^s Q + Q - Q^{\alpha+1}= 0 in R\mathbb{R}, where 0<s<10 < s < 1 and 0<α<4s12s0 < \alpha < \frac{4s}{1-2s} for s<1/2s < 1/2 and 0<α<0 < \alpha < \infty for s1/2s \geq 1/2. Here (Δ)s(-\Delta)^s denotes the fractional Laplacian in one dimension. In particular, we generalize (by completely different techniques) the specific uniqueness result obtained by Amick and Toland for s=1/2s=1/2 and α=1\alpha=1 in [Acta Math., \textbf{167} (1991), 107--126]. As a technical key result in this paper, we show that the associated linearized operator L+=(Δ)s+1(α+1)QαL_+ = (-\Delta)^s + 1 - (\alpha+1) Q^\alpha is nondegenerate; i.\,e., its kernel satisfies kerL+=span{Q}\mathrm{ker}\, L_+ = \mathrm{span}\, \{Q'\}. This result about L+L_+ proves a spectral assumption, which plays a central role for the stability of solitary waves and blowup analysis for nonlinear dispersive PDEs with fractional Laplacians, such as the generalized Benjamin-Ono (BO) and Benjamin-Bona-Mahony (BBM) water wave equations.Comment: 45 page

    Thermal Hall conductivity of marginal Fermi liquids subject to out-of plane impurities in high-TcT_c cuprates

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    The effect of out-of-plane impurities on the thermal Hall conductivity κxy\kappa_{xy} of in-plane marginal-Fermi-liquid (MFL) quasiparticles in high-TcT_c cuprates is examined by following the work on electrical Hall conductivity σxy\sigma_{xy} by Varma and Abraham [Phys. Rev. Lett. 86, 4652 (2001)]. It is shown that the effective Lorentz force exerted by these impurities is a weak function of energies of the MFL quasiparticles, resulting in nearly the same temperature dependence of κxy/T\kappa_{xy}/T and σxy\sigma_{xy}, indicative of obedience of the Wiedemann-Franz law. The inconsistency of the theoretical result with the experimental one is speculated to be the consequence of the different amounts of out-of-plane impurities in the two YBaCuO samples used for the κxy\kappa_{xy} and σxy\sigma_{xy} measurements.Comment: 5 pages, 2 eps figures; final versio

    QCD Loop Corrections to Top Production and Decay at e^+ e^- Colliders

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    We present a computation of QCD next-to-leading order virtual corrections to the top production and decay process at linear colliders. The top quarks are allowed to be off-shell and the production and decay subprocesses are treated together, thus allowing for interference effects. The framework employed for our computation is the double pole approximation (DPA). We describe the implementation of this approximation for the top production and decay process and compare it with the implementation of DPA for the evaluation of QED corrections to the W pair production at LEP II. Similarities and differences between the two cases are pointed out. One result of interest is the incomplete cancelation of interference corrections. Other results include values for the total NLO top production cross section, and the impact the nonfactorizable (interference) corrections have on the top invariant mass distribution.Comment: 27 pages, 8 ps figures; reference added to introductio
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