CMB Lensing Reconstruction in Real Space

We explore the reconstruction of the gravitational lensing field of the cosmic microwave background in real space showing that very little statistical information is lost when estimators of short range on the celestial sphere are used in place of the customary estimators in harmonic space, which are nonlocal and in principle require a simultaneous analysis of the entire sky without any cuts or excisions. Because virtually all the information relevant to lensing reconstruction lies on angular scales close to the resolution scale of the sky map, the gravitational lensing dilatation and shear fields (which unlike the deflection field or lensing potential are directly related to the observations in a local manner) may be reconstructed by means of quadratic combinations involving only very closely separated pixels. Even though harmonic space provides a more natural context for understanding lensing reconstruction theoretically, the real space methods developed here have the virtue of being faster to implement and are likely to prove useful for analyzing realistic maps containing a galactic cut and possibly numerous small excisions to exclude point sources that cannot be reliably subtracted.Comment: 21 pages, 8 figure

Magnetic Behavior in RRhX (R = rare earths; X=B, C) Compounds

We report on the magnetic behavior of RRhB (R = La, Ce, Pr, Nd, Gd, Tb and Tm) and RRhC (R = La, Ce, Pr and Gd) compounds crystallizing in the cubic perovskite type structure with space group Pm3m. The heat capacity data on Pauli-paramagnetic LaRhB and LaRhC indicate a high frequency vibrating motion of boron and carbon atoms in the unit cell. Ce is in -like nonmagnetic state in both the compounds. Pr compounds show a dominant crystal field effect with a nonmagnetic singlet ground state in PrRhB and a nonmagnetic quadrupolar doublet in PrRhC. Compounds with other rare earths order ferromagnetically at low temperatures except TmRhB in which the zero field evolution of magnetic interactions is relatively more complicated. The electrical resistivity of GdRhB decreases with increasing temperature in the paramagnetic state in the vicinity of T, which is rarely seen in ferromagnets. The behavior is discussed to be arising due to the short range spin fluctuation and a possible contribution from Fermi surface geometry.Comment: 14 Figs and a text fil

SO(10) Cosmic Strings and SU(3) Color Cheshire Charge

Certain cosmic strings that occur in GUT models such as $SO(10)$ can carry a magnetic flux which acts nontrivially on objects carrying $SU(3)_{color}$ quantum numbers. We show that such strings are non-Abelian Alice strings carrying nonlocalizable colored ``Cheshire" charge. We examine claims made in the literature that $SO(10)$ strings can have a long-range, topological Aharonov-Bohm interaction that turns quarks into leptons, and observe that such a process is impossible. We also discuss flux-flux scattering using a multi-sheeted formalism.Comment: 37 Pages, 8 Figures (available upon request) phyzzx, iassns-hep-93-6, itp-sb-93-6

Energy, Nutrient and Food Intakes of Male Shift Workers Vary According to the Schedule Type but Not the Number of Nights Worked.

Shift work is associated with increased risk of chronic diseases due to circadian rhythm disruptions and behavioral changes such as in eating habits. Impact of type of shifts and number of night shifts on energy, nutrient and food intake is as yet unknown. Our goal was to analyze shift workers' dietary intake, eating behavior and eating structure, with respect to frequency of nights worked in a given week and seven schedule types. Eating habits and dietary intakes of 65 male shift workers were analyzed in three steps based on 365 24-h food records: (1) according to the number of nights, (2) in a pooled analysis according to schedule type, and (3) in search of an interaction of the schedule and the timing of intake. Mean nutrient and food group intake during the study period did not depend on the number of nights worked. Amount and distribution of energy intake as well as quality of food, in terms of nutrient and food groups, differed depending on the type of schedule, split night shifts and recovery day (day after night shift) being the most impacted. Shift workers' qualitative and quantitative dietary intakes varied between different schedules, indicating the need for tailored preventive interventions

Confining Flux Tubes in a Current Algebra Approach

We describe flux tubes and their interactions in a low energy sigma model induced by $SU({N_f}) \rightarrow SO({N_f})$ flavor symmetry breaking in $SO(N_c)$ QCD. Unlike standard QCD, this model allows gauge confinement to manifest itself in the low energy theory, which has unscreened spinor color sources and global $Z_2$ flux tubes. We construct the flux tubes and show how they mediate the confinement of spinor sources. We further examine the flux tubes' quantum stability, spectrum and interactions. We find that flux tubes are Alice strings, despite ambiguities in defining parallel transport. Furthermore, twisted loops of flux tube support skyrmion number, just as gauged Alice strings form loops that support monopole charge. This model, while phenomenologically nonviable, thus affords a perspective on both the dynamics of confinement and on subtleties which arise for global Alice strings.Comment: 29 pages (REVTEX) plus 6 figures, two corrections in the final section and added reference

Charge Violation and Alice Behavior in Global and Textured Strings

Spontaneous breaking of global symmetries can produce ``Alice'' strings: line defects which make unbroken symmetries multivalued, induce apparent charge violation via Aharonov-Bohm interactions, and form point defects when twisted into loops. We demonstrate this behavior for both divergent and textured global Alice strings. Both adiabatically scatter charged particles via effective Wilson lines. For textured Alice strings, such Wilson lines occur at all radii, and are multivalued only inside the string. This produces measurable effects, including path-dependent charge violation.Comment: 32 pages, 2 epsfigs, Revte

Optical conductivity of the Kondo insulator YbB_12: Gap formation and low-energy excitations

Optical reflectivity experiments have been conducted on single crystals of the Kondo insulator YbB_12 in order to obtain its optical conductivity, \sigma(\omega). Upon cooling below 70 K, a strong supression of \sigma(\omega) is seen in the far-infrared region, indicating the opening of an energy gap of ~ 25 meV. This gap development is coincident with a rapid decrease in the magnetic susceptibility, which shows that the gap opening has significant influence on magnetic properties. A narrow, asymmetric peak is observed at ~40 meV in \sigma(\omega), which is attributed to optical transitions between the Yb 4f-derived states across the gap. In addition, a broad peak is observed at ~0.25 eV. This peak is attributed to transitions between Yb 4f-derived states and p-d band, and is reminiscent of similar peaks previously observed for rare-earth hexaborides.Comment: 4 pages, 4 figure

Cosmological Perturbations Generated in the Colliding Bubble Braneworld Universe

We compute the cosmological perturbations generated in the colliding bubble braneworld universe in which bubbles filled with five-dimensional anti-de Sitter space (AdS5)expanding within a five dimensional de Sitter space (dS5) or Minkowski space (M5) collide to form a (3+1) dimensional local brane on which the cosmology is virtually identical to that of the Randall-Sundrum model. The perturbation calculation presented here is valid to linear order but treats the fluctuations of the expanding bubbles as (3+1) dimensional fields localized on the bubble wall. We find that for bubbles expanding in dS5 the dominant contribution to the power spectrum is `red' but very small except in certain cases where the fifth dimension is not large or the bubbles have expanded to far beyond the dS5 apparent horizon length. This paper supersedes a previous version titled "Exactly Scale-Invariant Cosmological Perturbations From a Colliding Bubble Braneworld Universe" in which we erroneously claimed that a scale-invariant spectrum results for the case of bubbles expanding in M5. This present paper corrects the errors of the previous version and extends the analysis to the more interesting and general case of bubbles expanding in dS5.Comment: 29 pages Latex with eps figures. Major errors in the original version of the paper corrected and analysis extended to bubbles expanding in dS

Spin and charge dynamics of the ferromagnetic and antiferromagnetic two-dimensional half-filled Kondo lattice model

We present a detailed numerical study of spin and charge dynamics of the two-dimensional Kondo lattice model with hopping t and exchange J. At T=0 and J > 0, the competition between the RKKY interaction and Kondo effect triggers a quantum phase transition between magnetically ordered and disordered insulators: J_c/t = 1.45(5). The quasiparticle gap scales as |J|. S(q,\omega), evolves smoothly from its strong coupling form with spin gap at q = (\pi,\pi) to a spin wave form. At J>0, A(\vec{k},\omega) shows a dispersion relation following that of hybridized bands. For J < J_c this feature is supplemented by shadows thus pointing to a coexistence of Kondo screening and magnetism. For J < 0 A(\vec{k},\omega) is similar to that of non-interacting electrons in a staggered magnetic field. Spin, T_S, and charge, T_C, scales are defined. For weak to intermediate couplings, T_S marks the onset of antiferromagnetic fluctuations and follows a J^2 law. At strong couplings T_S scales as J. T_C scales as J both at weak and strong couplings. At and slightly below T_C we observe i) a rise in the resistivity as a function of decreasing temperature, ii) a dip in the integrated density of states at the Fermi energy and iii) the occurrence of hybridized bands in A(k,\omega). It is shown that in the weak coupling limit, the charge gap of order J is of magnetic origin. The specific heat shows a two peak structure, the low temperature peak being of magnetic origin. Our results are compared to various mean-field theories.Comment: 30 pages, 24 figure

Tract-based spatial statistics to assess the neuroprotective effect of early erythropoietin on white matter development in preterm infants

In a randomized double-blind placebo-controlled trial, O'Gorman et al. show that administration of erythropoietin within the first 42 hours after preterm birth improves white matter development in preterm infants. Improvements are seen in the corpus callosum, the anterior and posterior limbs of the internal capsule, and the corticospinal tract bilaterall