Minimizing Artifacts in Analysis of Surface Statistics

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On the third level descendent fields in the Bullough-Dodd model and its reductions

Exact vacuum expectation values of the third level descendent fields $$ in the Bullough-Dodd model are proposed. By performing quantum group restrictions, we obtain $<L_{-3}{\bar L}_{-3}{\Phi}_{lk}>$ in perturbed minimal conformal field theories.Comment: 7 pages, LaTeX file with amssymb; to appear in Phys. Lett.

Particle Formation and Ordering in Strongly Correlated Fermionic Systems: Solving a Model of Quantum Chromodynamics

In this paper we study a (1+1)-dimensional version of the famous Nambu-Jona-Lasinio model of Quantum Chromodynamics (QCD2) both at zero and finite hadron density. We use non-perturbative techniques (non-Abelian bosonization and Truncated Conformal Space Approach). At zero density we describe a formation of fermion three-quark (nucleons and $\Delta$-baryons) and boson (two-quark mesons, six-quark deuterons) bound states and also a formation of a topologically nontrivial phase. At finite hadron density, the model has a rich phase diagram which includes phases with density wave and superfluid quasi-long-range (QLR) order and also a phase of a baryon Tomonaga-Luttinger liquid (strange metal). The QLR order results as a condensation of scalar mesons (the density wave) or six-quark bound states (deuterons).Comment: 31 pages, pdflatex file, 7 figures; typos corrected, the version from Phys. Rev.

Exact Maximal Height Distribution of Fluctuating Interfaces

We present an exact solution for the distribution P(h_m,L) of the maximal height h_m (measured with respect to the average spatial height) in the steady state of a fluctuating Edwards-Wilkinson interface in a one dimensional system of size L with both periodic and free boundary conditions. For the periodic case, we show that P(h_m,L)=L^{-1/2}f(h_m L^{-1/2}) for all L where the function f(x) is the Airy distribution function that describes the probability density of the area under a Brownian excursion over a unit interval. For the free boundary case, the same scaling holds but the scaling function is different from that of the periodic case. Numerical simulations are in excellent agreement with our analytical results. Our results provide an exactly solvable case for the distribution of extremum of a set of strongly correlated random variables.Comment: 4 pages revtex (two-column), 1 .eps figure include

High-field Zeeman effect of shallow acceptors in germanium

Zeeman absorption spectra have been obtained for B and Ga in Ge for B∥〈100〉 in the Voigt configuration with plane-polarized radiation. All twelve allowed transitions were observed for both the G and D lines. The corresponding excited states of these two lines for both impurities behave identically; two recent theoretical results are in good agreement. The measurements are a sensitive probe of the ground states; there are differences between the behavior of these for the two acceptors

A comparison of smooth basis constructions for isogeometric analysis

In order to perform isogeometric analysis with increased smoothness on complex domains, trimming, variational coupling or unstructured spline methods can be used. The latter two classes of methods require a multi-patch segmentation of the domain, and provide continuous bases along patch interfaces. In the context of shell modeling, variational methods are widely used, whereas the application of unstructured spline methods on shell problems is rather scarce. In this paper, we therefore provide a qualitative and a quantitative comparison of a selection of unstructured spline constructions, in particular the D-Patch, Almost-$C^1$, Analysis-Suitable $G^1$ and the Approximate $C^1$ constructions. Using this comparison, we aim to provide insight into the selection of methods for practical problems, as well as directions for future research. In the qualitative comparison, the properties of each method are evaluated and compared. In the quantitative comparison, a selection of numerical examples is used to highlight different advantages and disadvantages of each method. In the latter, comparison with weak coupling methods such as Nitsche's method or penalty methods is made as well. In brief, it is concluded that the Approximate $C^1$ and Analysis-Suitable $G^1$ converge optimally in the analysis of a bi-harmonic problem, without the need of special refinement procedures. Furthermore, these methods provide accurate stress fields. On the other hand, the Almost-$C^1$ and D-Patch provide relatively easy construction on complex geometries. The Almost-$C^1$ method does not have limitations on the valence of boundary vertices, unlike the D-Patch, but is only applicable to biquadratic local bases. Following from these conclusions, future research directions are proposed, for example towards making the Approximate $C^1$ and Analysis-Suitable $G^1$ applicable to more complex geometries

Sensor Development for the Large Synoptic Survey Telescope.

The Large Synoptic Survey project proposes to build an 8m-class ground-based telescope with a dedicated wide field camera. The camera consists of a large focal plane mosaic composed of multi-output CCDs with extended red response. Design considerations and preliminary characterization results for the sensors are presented in this contribution to the Workshop

Accuracy Limitations in Long Trace Profilometry

As requirements for surface slope error quality of grazing incidence optics approach the 100 nanoradian level, it is necessary to improve the performance of the measuring instruments to achieve accurate and repeatable results at this level. We have identified a number of internal error sources in the Long Trace Profiler (LTP) that affect measurement quality at this level. The LTP is sensitive to phase shifts produced within the millimeter diameter of the pencil beam probe by optical path irregularities with scale lengths of a fraction of a millimeter. We examine the effects of mirror surface ''macroroughness'' and internal glass homogeneity on the accuracy of the LTP through experiment and theoretical modeling. We will place limits on the allowable surface ''macroroughness'' and glass homogeneity required to achieve accurate measurements in the nanoradian range