Digital Commons Network^™

Superfluid Transition In A Rotating Fermi Gas With Resonant Interactions, Martin Y. Veillette, Daniel E. Sheehy, Leo Radzihovsky, Victor Gurarie

Faculty Publications

We study a rotating atomic Fermi gas near a narrow s-wave Feshbach resonance in a uniaxial trap with frequencies Ω⊥, Ωz. We predict the upper-critical angular velocity, ωc2(δ,T), as a function of temperature T and detuning δ across the BEC-BCS crossover. The suppression of superfluidity at ωc2 is distinct in the BCS and BEC regimes, with the former controlled by depairing and the latter by the dilution of bosonic molecules. At low T and Ωz 〉 Ω⊥, in the BCS and crossover regimes of 0 δ δc, ωc2 is implicitly given by ωc22+Ω2 ≈ 2Δ Ω/F, vanishing as ωc2∼Ω (1-δ/δc)1/2 …

Epinecrophylla, A New Genus Of Antwrens (Aves: Passeriformes: Thamnophilidae), Morton L. Isler, Daniela Rodrigues Lacerda, Phyllis R. Isler, Shannon J. Hackett, Kenneth V. Rosenberg, Robb T. Brumfield

Faculty Publications

We offer a new generic name for the stipple-throated assemblage of antwrens (Thamnophilidae) currently placed in the genus Myrmotherula. Molecular studies demonstrated that Myrmotherula is polyphyletic, with the stippled-throated group forming a clade that is not sister to any other currently recognized Myrmotherula species. The stipple-throated assemblage is distinguished morphologically by at least one sex having a black throat stippled white or buffy white combined with a comparatively long, unmarked tail, although three populations considered subspecies have lost one of these characters. The distinct evolution of this assemblage is supported by diagnostic behavioral characters derived from foraging behaviors, vocal repertoires, …

Uniform Discretizations: A New Approach For The Quantization Of Totally Constrained Systems, Miguel Campiglia, Cayetano Di Bartolo, Rodolfo Gambini, Jorge Pullin

Faculty Publications

We discuss in detail the uniform discretization approach to the quantization of totally constrained theories. This approach allows to construct the continuum theory of interest as a well defined, controlled, limit of well behaved discrete theories. We work out several finite dimensional examples that exhibit behaviors expected to be of importance in the quantization of gravity. We also work out the case of BF theory. At the time of quantization, one can take two points of view. The technique can be used to define, upon taking the continuum limit, the space of physical states of the continuum constrained theory of …

A Search For Neutrinos From The Solar Hep Reaction And The Diffuse Supernova Neutrino Background With The Sudbury Neutrino Observatory, B. Aharmim, S. N. Ahmed, A. E. Anthony, E. W. Beier, A. Bellerive, M. Bergevin, S. D. Biller, M. G. Boulay, Y. D. Chan, M. Chen, X. Chen, B. T. Cleveland, G. A. Cox, C. A. Currat, X. Dai, F. Dalnoki-Veress, H. Deng, J. Detwiler, M. Dimarco, P. J. Doe, G. Doucas, P. L. Drouin, F. A. Duncan, M. Dunford, J. A. Dunmore, E. D. Earle, H. C. Evans, G. T. Ewan

Faculty Publications

A search has been made for neutrinos from the hep reaction in the Sun and from the diffuse supernova neutrino background (DSNB) using data collected during the first operational phase of the Sudbury Neutrino Observatory, with an exposure of 0.65 ktons yr. For the hep neutrino search, two events are observed in the effective electron energy range of 14.3 MeV < Teff < 20 MeV, where 3.1 background events are expected. After accounting for neutrino oscillations, an upper limit of 2.3 × 104 cm-2 s-1 at the 90% confidence level is inferred on the integral total flux of hep neutrinos. For DSNB neutrinos, no events are observed in the effective electron energy range of 21 MeV < Teff < 35 MeV, and, consequently, an upper limit on the νe component of the DSNB flux in the neutrino energy range of 22.9 MeV < Eν < 36.9 MeVof 70 cm-2 s-1 is inferred at the 90% confidence level. This is an improvement by a factor of 6.5 on the previous best upper limit on the hep neutrino flux and by 2 orders of magnitude on the previous upper limit on the νe component of the DSNB flux. © 2006. The American Astronomical Society. All rights reserved.

Geological And Oceanographic Perspectives On Event Bed Formation During Hurricane Katrina, T. R. Keen, Y. Furukawa, S. J. Bentley, R. L. Slingerland, W. J. Teague, J. D. Dykes, C. D. Rowley

Faculty Publications

Storm deposits in ancient shelf sediments typically form thick sequences of interbedded sand and mud deposited during shoreline regression, whereas modern shelf sediments are generally thin veneers deposited during shoreline transgression. In this paper we present a preliminary comparison between ancient and modern storm beds deposited in these disparate contexts. Hurricane Katrina deposited a storm bed on the Louisiana shelf with a maximum observed thickness of 0.58 m, which thinned to approximately 0.1 m at 200 km west of landfall. This thickness is similar to event beds observed in both ancient and modern sediments. Using data for tropical cyclone landfalls …

Horospherical Model For Holomorphic Discrete Series And Horospherical Cauchy Transform, Simon Gindikin, Bernhard Krötz, Gestur Ólafsson

Faculty Publications

We define a complex horospherical transform on an affine symmetric space X = G/H of Hermitian type and show that it has no kernel on the representations of the H-spherical holomorphic discrete series. © Foundation Compositio Mathematica 2006.

On The Head And The Tail Of The Colored Jones Polynomial, Oliver T. Dasbach, Xiao Song Lin

Faculty Publications

The colored Jones polynomial is a function JK: ℕ → ℤ[t,t-1] associated with a knot K in 3-space. We will show that for an alternating knot K the absolute values of the first and the last three leading coefficients of JK(n) are independent of n when n is sufficiently large. Computation of sample knots indicates that this should be true for any fixed leading coefficient of the colored Jones polynomial for alternating knots. As a corollary we get a volume-ish theorem for the colored Jones polynomial. © Foundation Compositio Mathematica 2006.

Rapid Decay Of Tree-Community Composition In Amazonian Forest Fragments, William F. Laurance, Henrique E.M. Nascimento, Susan G. Laurance, Ana Andrade, José E.L.S. Ribeiro, Juan Pablo Giraldo, Thomas E. Lovejoy, Richard Condit, Jerome Chave, Kyle E. Harms, Sammya D'Angelo

Faculty Publications

Forest fragmentation is considered a greater threat to vertebrates than to tree communities because individual trees are typically long-lived and require only small areas for survival. Here we show that forest fragmentation provokes surprisingly rapid and profound alterations in Amazonian tree-community composition. Results were derived from a 22-year study of exceptionally diverse tree communities in 40 1-ha plots in fragmented and intact forests, which were sampled repeatedly before and after fragment isolation. Within these plots, trajectories of change in abundance were assessed for 267 genera and 1,162 tree species. Abrupt shifts in floristic composition were driven by sharply accelerated tree …

Detection Of The Irradiated Donor In The Lmxbs 4u 1636-536 (=V801 Ara) And 4u 1735-444 (=V926 Sco), J. Casares, R. Cornelisse, D. Steeghs, P. A. Charles, R. I. Hynes, K. O'Brien, T. E. Strohmayer

Faculty Publications

Phase-resolved VLT spectroscopy of the bursting low-mass X-ray binaries 4U 1636-536/V801 Ara and 4U 1735-444/V926 Sco is presented. Doppler images of the N III λ4640 Bowen transition reveal compact spots which we attribute to fluorescent emission from the donor star and enable us to define a new set of spectroscopic ephemerides. We measure K em = 277 ± 22 and 226 ± 22 kms -1 from the N III spots in V801 Ara and V926 Sco, respectively, which represent strict lower limits to the radial velocity semi-amplitude of the donor stars. Our new ephemerides provide confirmation that light-curve maxima in …

Holomorphic Horospherical Transform On Noncompactly Causal Spaces, Simon Gindikin, Bernhard Krötz, Gestur Ólafsson

Faculty Publications

We develop integral geometry for noncompactly causal symmetric spaces. We define a complex horospherical transform and, for some cases, identify it with a Cauchy-type integral.

Early Spectral Evolution Of Nova Sagittarii 2004 (V5114 Sagittarii), A. Ederoclite, E. Mason, M. Della Valle, R. Gilmozzi, R. E. Williams, L. Germany, I. Saviane, F. Matteucci, B. E. Schaefer, F. Walter, R. J. Rudy, D. Lynch, S. Mazuk, C. C. Venturini, R. C. Puetter, R. B. Perry, W. Liller, A. Rotter

Faculty Publications

Aims. We present optical and near-infrared spectral evolution of the Galactic nova V5114 Sgr (2004) during few months after the outburst. Methods. We use multi-band photometry and line intensities derived from spectroscopy to put constrains on the distance and the physical conditions of the ejecta of V5114 Sgr. Results. The nova showed a fast decline to - 11 days) and spectral features of Fen spectroscopic class. It reached Mv = -8.7 ± 0.2 mag at maximum light, from which we derive a distance of 7700 ± 700 kpc and a distance from the galactic plane of about 800 pc. Hydrogen …

M-Body Pure State Entanglement, Feng Pan, J. P. Draayer

Faculty Publications

The simple entanglement of N-body N-particle pure states is extended to the more general M-body or M-body N-particle states where N ≠ M. Some new features of the M-body N-particle pure states a re discussed. An application of the measure to quantify quantum correlations in a Bose-Einstien condensate model is demonstrated. © 2006 World Scientific Publishing Company.

Fundamental Spatio-Temporal Decoherence: A Key To Solving The Conceptual Problems Of Black Holes, Cosmology And Quantum Mechanics, Rodolfo Gambini, Rafael A. Porto, Jorge Pullin

Faculty Publications

Unitarity is a pillar of quantum theory. Nevertheless, it is also a source of several of its conceptual problems. We note that in a world where measurements are relational, as is the case in gravitation, quantum mechanics exhibits a fundamental level of loss of coherence. This can be the key to solving, among others, the puzzles posed by the black hole information paradox, the formation of inhomogeneities in cosmology and the measurement problem in quantum mechanics. © World Scientific Publishing Company.

Sines Of A Nearly Perfect Character, David A. Ray, Jinchuan Xing, Abdel Halim Salem, Mark A. Batzer

Faculty Publications

Mobile elements have been recognized as powerful tools for phylogenetic and population-level analyses. However, issues regarding potential sources of homoplasy and other misleading events have been raised. We have collected available data for all phylogenetic and population level studies of primates utilizing Alu insertion data and examined them for potentially homoplasious and other misleading events. Very low levels of each potential confounding factor in a phylogenetic or population analysis (i.e., lineage sorting, parallel insertions, and precise excision) were found. Although taxa known to be subject to high levels of these types of events may indeed be subject to problems when …

Homogenization And Field Concentrations In Heterogeneous Media, Robert Lipton

Faculty Publications

A multiscale characterization of the field concentrations inside composite and polycrystalline media is developed. We focus on gradient fields associated with the intensive quantities given by the temperature and the electric potential. In the linear regime these quantities are modeled by the solution of a second order elliptic partial differential equation with oscillatory coefficients. The characteristic length scale of the heterogeneity relative to the sample size is denoted by ε and the intensive quantity is denoted by u ε. Field concentrations are measured using the L p norm of the gradient field ||∇u ε||L p(D) for 2 ≤ p < ∞. The analysis focuses on the case when 0 < ε ≪ 1. Explicit lower bounds on lim inf ε→0 are developed. These bounds provide a way to rigorously assess field concentrations generated by the microgeometry without having to compute the actual field u ε. © 2006 Society for Industrial and Applied Mathematics.

Optimization Of Composite Structures Subject To Local Stress Constraints, Robert Lipton, Michael Stuebner

Faculty Publications

An extension of current methodologies is introduced for optimization of graded microstructure subject to local stress criteria. The method is based on new multiscale stress criteria given by macrostress modulation functions. The modulation functions quantify the intensity of local stress fluctuations at the scale of the microstructure due to the imposed macroscopic stress. The methodology is illustrated for long cylindrical shafts reinforced with stiff cylindrical elastic fibers with generators parallel to the shaft. Examples are presented for shaft cross sections that possess reentrant corners typically seen in lap joints and junctions of struts. It is shown that the computational methodology …

Uncle Tom Mania: Slavery, Minstrelsy, And Transatlantic Culture In The 1850s, Elizabeth Ammons

Civil War Book Review

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Interpretations of the Effect of Stowe's Novel

The Lincolns In The White House: Four Years That Shattered A Family, Pederson. William D.

Civil War Book Review

The East Wing in Crisis

Civil Strife in the Presidential Family

What Lincoln Believed: The Values And Convictions Of America's Greatest President, Frank J. Williams

Civil War Book Review

Presidential Values

The Inner Thoughts of Abraham Lincoln

Cities Of The Dead: Contesting The Memory Of The Civil War In The South, 1865-1914, Geraldo Lujan Cadava

Civil War Book Review

Continual Strife and Public Memory

Commemorations in the aftermath of the War

Civil War Time: Temporality And Identity In America, 1861-1865, Amy R. Minton

Civil War Book Review

Perception and Relativity

The Experience of Time during the Civil War

Defining Moments: African American Commemoration & Political Culture In The South, 1863-1913, Mitch Kachun

Civil War Book Review

African American Commemorations

The Control of Past and a Hold on the Future

Donnybrook: The Battle Of Bull Run, 1861, Stacy D. Allen

Civil War Book Review

Shattered Expectations

The Battle for Manassas

Mark Twain In Japan: The Cultural Reception Of An American Icon, Russell Reising

Civil War Book Review

American Literature in an Eastern Culture

Japanese Interpretation and Absorption of Mark Twain

Mary Edwards Walker: Above And Beyond, Giselle Roberts

Civil War Book Review

A Life of Service

Defying Convention and Attaining the Medal of Honour