Text Image Compression Based on the Formation and Classification of Vertical Elements of a Row in the Graphical Dictionary of Symbol Data

Text Image Compression Based on the Formation and Classification of Vertical Elements of a Row in the Graphical Dictionary of Symbol Data

Text Image Compression Based on the Formation and Classification of Vertical Elements of a Row in the Graphical Dictionary of Symbol Data

Text Image Compression Based on the Formation and Classification of Vertical Elements of a Row in the Graphical Dictionary of Symbol Data

Epitaxial growth and structural characterization of Pb(Fe1/2Nb1/2)O3 thin films

We have grown lead iron niobate thin films with composition Pb(Fe1/2Nb1/2)O3 (PFN) on (0 0 1) SrTiO3 substrates by pulsed laser deposition. The influence of the deposition conditions on the phase purity was studied. Due to similar thermodynamic stability spaces, a pyrochlore phase often coexists with the PFN perovskite phase. By optimizing the kinetic parameters, we succeeded in identifying a deposition window which resulted in epitaxial perovskite-phase PFN thin films with no identifiable trace of impurity phases appearing in the X-ray diffractograms. PFN films having thicknesses between 20 and 200 nm were smooth and epitaxially oriented with the substrate and as demonstrated by RHEED streaks which were aligned with the substrate axes. X-ray diffraction showed that the films were completely c-axis oriented and of excellent crystalline quality with low mosaicity (X-ray rocking curve FWHM<0.09). The surface roughness of thin films was also investigated by atomic force microscopy. The root-mean-square roughness varies between 0.9 nm for 50-nm-thick films to 16 nm for 100-nm-thick films. We also observe a correlation between grain size, surface roughness and film thickness.Comment: 13 Pages, 6 figures. To be published in J. Mag. Mag Mater. proceedings of EMRS200

Consistent Linearized Gravity in Brane Backgrounds

A globally consistent treatment of linearized gravity in the Randall-Sundrum background with matter on the brane is formulated. Using a novel gauge, in which the transverse components of the metric are non-vanishing, the brane is kept straight. We analyze the gauge symmetries and identify the physical degrees of freedom of gravity. Our results underline the necessity for non-gravitational confinement of matter to the brane.Comment: 15 page

Cosmology and Fermion Confinement in a Scalar-Field-Generated Domain Wall Brane in Five Dimensions

We consider a brane generated by a scalar field domain wall configuration in 4+1 dimensions, interpolating, in most cases, between two vacua of the field. We study the cosmology of such a system in the cases where the effective four-dimensional brane metric is de Sitter or anti de Sitter, including a discussion of the bulk coordinate singularities present in the de-Sitter case. We demonstrate that a scalar field kink configuration can support a brane with dS$_4$ cosmology, despite the presence of coordinate singularities in the metric. We examine the trapping of fermion fields on the domain wall for nontrivial brane cosmology.Comment: 29 pages, 12 figures; minor changes, accepted by JHE

The non-forward BFKL amplitude and rapidity gap physics

We discuss the BFKL approach to processes with large momentum transferred through a rapidity gap. The Mueller and Tang scheme to the BFKL non-forward parton-parton elastic scattering amplitude at large $t$, is extended to include higher conformal spins. The new contributions are found to decrease with increasing energy, as follows from the gluon reggeisation phenomenon, and to vanish for asymptotically high energies. However, at moderate energies and high $|t|$, the higher conformal spins dominate the amplitude. We illustrate the effects by studying the production of two high $E_T$ jets separated by a rapidity gap at HERA energies. In a simplified framework, we find excellent agreement with the HERA photoproduction data once we incorporate the rapidity gap survival probability against soft rescattering effects. We emphasize that measurements of the analogous process in electroproduction may probe different summations over conformal spins.Comment: Latex, 14 pages, 3 figures; the final version to appear in Phys. Lett. B; a short discussion of the Tevatron data added; a previously missing factor of i^n introduced in eq. (13

4D, N = 1 Supersymmetry Genomics (I)

Presented in this paper the nature of the supersymmetrical representation theory behind 4D, N = 1 theories, as described by component fields, is investigated using the tools of Adinkras and Garden Algebras. A survey of familiar matter multiplets using these techniques reveals they are described by two fundamental valise Adinkras that are given the names of the cis-Valise (c-V) and the trans-Valise (t-V). A conjecture is made that all off-shell 4D, N = 1 component descriptions of supermultiplets are associated with two integers - the numbers of c-V and t-V Adinkras that occur in the representation.Comment: 53 pages, 19 figures, Report-II of SSTPRS 2008 Added another chapter for clarificatio

Hybrid configuration content of heavy S-wave mesons

We use the non-relativistic expansion of QCD (NRQCD) on the lattice to study the lowest hybrid configuration contribution to the ground state of heavy S-wave mesons. Using lowest-order lattice NRQCD to create the heavy-quark propagators, we form a basis of ``unperturbed'' S-wave and hybrid states. We then apply the lowest-order coupling of the quark spin and chromomagnetic field at an intermediate time slice to create ``mixed'' correlators between the S-wave and hybrid states. From the resulting amplitudes, we extract the off-diagonal element of our two-state Hamiltonian. Diagonalizing this Hamiltonian gives us the admixture of hybrid configuration within the meson ground state. The present effort represents a continuation of previous work: the analysis has been extended to include lattices of varying spacings, source operators having better overlap with the ground states, and the pseudoscalar (along with the vector) channel. Results are presented for bottomonium ($\Upsilon$, $\eta_b^{}$) using three different sets of quenched lattices. We also show results for charmonium ($J/\psi$, $\eta_c^{}$) from one lattice set, although we note that the non-relativistic approximation is not expected to be very good in this case.Comment: 9 pages, 7 figures, version to appear in Phys Rev

Common Scaling Patterns in Intertrade Times of U. S. Stocks

We analyze the sequence of time intervals between consecutive stock trades of thirty companies representing eight sectors of the U. S. economy over a period of four years. For all companies we find that: (i) the probability density function of intertrade times may be fit by a Weibull distribution; (ii) when appropriately rescaled the probability densities of all companies collapse onto a single curve implying a universal functional form; (iii) the intertrade times exhibit power-law correlated behavior within a trading day and a consistently greater degree of correlation over larger time scales, in agreement with the correlation behavior of the absolute price returns for the corresponding company, and (iv) the magnitude series of intertrade time increments is characterized by long-range power-law correlations suggesting the presence of nonlinear features in the trading dynamics, while the sign series is anti-correlated at small scales. Our results suggest that independent of industry sector, market capitalization and average level of trading activity, the series of intertrade times exhibit possibly universal scaling patterns, which may relate to a common mechanism underlying the trading dynamics of diverse companies. Further, our observation of long-range power-law correlations and a parallel with the crossover in the scaling of absolute price returns for each individual stock, support the hypothesis that the dynamics of transaction times may play a role in the process of price formation.Comment: 8 pages, 5 figures. Presented at The Second Nikkei Econophysics Workshop, Tokyo, 11-14 Nov. 2002. A subset appears in "The Application of Econophysics: Proceedings of the Second Nikkei Econophysics Symposium", editor H. Takayasu (Springer-Verlag, Tokyo, 2003) pp.51-57. Submitted to Phys. Rev. E on 25 June 200

Quantum Limits of Stochastic Cooling of a Bosonic Gas

The quantum limits of stochastic cooling of trapped atoms are studied. The energy subtraction due to the applied feedback is shown to contain an additional noise term due to atom-number fluctuations in the feedback region. This novel effect is shown to dominate the cooling efficiency near the condensation point. Furthermore, we show first results that indicate that Bose--Einstein condensation could be reached via stochastic cooling.Comment: 5 pages, 3 figures, to appear in Phys. Rev.