14,382 research outputs found
Seasonal Emergence Patterns of Black Flies (Diptera: Simuliidae) in Northwestern Pennsylvania
A two-year emergence trap study of black flies at four sites in northwestern Pennsylvania yielded 1%3 individuals of nine species. The collections included Prosimulium mixtum, P. jU5cum, Stegapterna mutata, Simulium aureum, S. excisum (recorded for the first time from Pennsylvania), S. gauldingi, S. sp. nr. innacens, S. vittatum, and S. tuberasum. Species richness for all sites peaked during May. Emergence collections below a sewage plant effluent outfall represented fewer individuals and species than collections above the effluent outfall. Chromosomal analysis of supplementary larval collections revealed the IIIL-l and IS-7 sibling species of S. vittatum and the FG sibling of S. tuberasum
High-Dimensional Topological Insulators with Quaternionic Analytic Landau Levels
We study the 3D topological insulators in the continuum by coupling spin-1/2
fermions to the Aharonov-Casher SU(2) gauge field. They exhibit flat Landau
levels in which orbital angular momentum and spin are coupled with a fixed
helicity. The 3D lowest Landau level wavefunctions exhibit the quaternionic
analyticity as a generalization of the complex analyticity of the 2D case. Each
Landau level contributes one branch of gapless helical Dirac modes to the
surface spectra, whose topological properties belong to the Z2-class. The flat
Landau levels can be generalized to an arbitrary dimension. Interaction effects
and experimental realizations are also studied
Beam-Energy and System-Size Dependence of Dynamical Net Charge Fluctuations
We present measurements of net charge fluctuations in collisions at
19.6, 62.4, 130, and 200 GeV, collisions at
62.4, 200 GeV, and collisions at 200
GeV using the net charge dynamical fluctuations measure . The
dynamical fluctuations are non-zero at all energies and exhibit a rather modest
dependence on beam energy. We find that at a given energy and collision system,
net charge dynamical fluctuations violate scaling, but display
approximate scaling. We observe strong dependence of dynamical
fluctuations on the azimuthal angular range and pseudorapidity widths.Comment: 4 pages, 4 figures, presented at the 19th International Conference on
Ultra-Relativistic Nucleus-Nucleus Collisions, "Quark Matter 2008", Jaipur,
India, February 4-10, 200
Canonical, squeezed and fermionic coherent states in a right quaternionic Hilbert space with a left multiplication on it
Using a left multiplication defined on a right quaternionic Hilbert space, we
shall demonstrate that various classes of coherent states such as the canonical
coherent states, pure squeezed states, fermionic coherent states can be defined
with all the desired properties on a right quaternionic Hilbert space. Further,
we shall also demonstrate squeezed states can be defined on the same Hilbert
space, but the noncommutativity of quaternions prevents us in getting the
desired results.Comment: Conference paper. arXiv admin note: text overlap with
arXiv:1704.02946; substantial text overlap with arXiv:1706.0068
Billiard algebra, integrable line congruences, and double reflection nets
The billiard systems within quadrics, playing the role of discrete analogues
of geodesics on ellipsoids, are incorporated into the theory of integrable
quad-graphs. An initial observation is that the Six-pointed star theorem, as
the operational consistency for the billiard algebra, is equivalent to an
integrabilty condition of a line congruence. A new notion of the
double-reflection nets as a subclass of dual Darboux nets associated with
pencils of quadrics is introduced, basic properies and several examples are
presented. Corresponding Yang-Baxter maps, associated with pencils of quadrics
are defined and discussed.Comment: 18 pages, 8 figure
Backlund transformations for the sl(2) Gaudin magnet
Elementary, one- and two-point, Backlund transformations are constructed for
the generic case of the sl(2) Gaudin magnet. The spectrality property is used
to construct these explicitly given, Poisson integrable maps which are
time-discretizations of the continuous flows with any Hamiltonian from the
spectral curve of the 2x2 Lax matrix.Comment: 17 pages, LaTeX, refs adde
Non-colliding Brownian Motions and the extended tacnode process
We consider non-colliding Brownian motions with two starting points and two
endpoints. The points are chosen so that the two groups of Brownian motions
just touch each other, a situation that is referred to as a tacnode. The
extended kernel for the determinantal point process at the tacnode point is
computed using new methods and given in a different form from that obtained for
a single time in previous work by Delvaux, Kuijlaars and Zhang. The form of the
extended kernel is also different from that obtained for the extended tacnode
kernel in another model by Adler, Ferrari and van Moerbeke. We also obtain the
correlation kernel for a finite number of non-colliding Brownian motions
starting at two points and ending at arbitrary points.Comment: 38 pages. In the revised version a few arguments have been expanded
and many typos correcte
Comment on ``Validity of certain soft-photon amplitudes''
The criteria suggested by Welsh and Fearing (nucl-th/9606040) to judge the
validity of certain soft-photon amplitudes are examined. We comment on aspects
of their analysis which lead to incorrect conclusions about published
amplitudes and point out important criteria which were omitted from their
analysis.Comment: 6 pages plus 1 postscript figure, Revte
Quaternionic Electroweak Theory
We explicitly develop a quaternionic version of the electroweak theory, based
on the local gauge group . The need of a complex
projection for our Lagrangian and the physical significance of the anomalous
scalar solutions are also discussed.Comment: 12 pages, Revtex, submitted to J. Phys.
Path Integral Monte Carlo study of phonons in the bcc phase of He
Using Path Integral Monte Carlo and the Maximum Entropy method, we calculate
the dynamic structure factor of solid He in the bcc phase at a finite
temperature of T = 1.6 K and a molar volume of 21 cm. Both the
single-phonon contribution to the dynamic structure factor and the total
dynamic structure factor are evaluated. From the dynamic structure factor, we
obtain the phonon dispersion relations along the main crystalline directions,
[001], [011] and [111]. We calculate both the longitudinal and transverse
phonon branches. For the latter, no previous simulations exist. We discuss the
differences between dispersion relations resulting from the single-phonon part
vs. the total dynamic structure factor. In addition, we evaluate the formation
energy of a vacancy.Comment: 10 figure
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