5,215 research outputs found
Structure of solutions of the Skyrme model on three-sphere. Numerical results
The hedgehog Skyrme model on three-sphere admits very rich spectrum of
solitonic solutions which can be encompassed by a strikingly simple scheme. The
main result of this paper is the statement of the tripartite structure of
solutions of the model and the discovery in what configurations these solutions
appear. The model contains features of more complicated models in General
Relativity and as such can give insight into them.Comment: 20 pages, 13 figures in, with emai
Plasmonic Hot Spots in Triangular Tapered Graphene Microcrystals
Recently, plasmons in graphene have been observed experimentally using
scattering scanning near-field optical microscopy. In this paper, we develop a
simplified analytical approach to describe the behavior in triangular samples.
Replacing Coulomb interaction by a short-range one reduces the problem to a
Helmholtz equation, amenable to analytical treatment. We demonstrate that even
with our simplifications, the system still exhibits the key features seen in
the experiment.Comment: 4 pages, 3 figure
Results from the CASTLES Survey of Gravitational Lenses
We show that most gravitational lenses lie on the passively evolving
fundamental plane for early-type galaxies. For burst star formation models (1
Gyr of star formation, then quiescence) in low Omega_0 cosmologies, the stellar
populations of the lens galaxies must have formed at z_f > 2. Typical lens
galaxies contain modest amounts of patchy extinction, with a median
differential extinction for the optical (radio) selected lenses of E(B-V) =
0.04 (0.07) mag. The dust can be used to determine both extinction laws and
lens redshifts. For example, the z_l=0.96 elliptical lens in MG0414+0534 has an
R_V=1.7 +/- 0.1 mean extinction law. Arc and ring images of the quasar and AGN
source host galaxies are commonly seen in NICMOS H band observations. The hosts
are typically blue, L < L_* galaxies.Comment: 12 pages, 10 figures, from Proceedings of the 9th Annual Astrophysics
Conference in Maryland, After the Dark Ages: When Galaxies Were Youn
Infrared nano-spectroscopy and imaging of collective superfluid excitations in conventional and high-temperature superconductors
We investigate near-field infrared spectroscopy and superfluid polariton
imaging experiments on conventional and unconventional superconductors. Our
modeling shows that near-field spectroscopy can measure the magnitude of the
superconducting energy gap in Bardeen-Cooper-Schrieffer-like superconductors
with nanoscale spatial resolution. We demonstrate how the same technique can
measure the c-axis plasma frequency, and thus the c-axis superfluid density, of
layered unconventional superconductors with a similar spatial resolution. Our
modeling also shows that near-field techniques can image superfluid surface
mode interference patterns near physical and electronic boundaries. We describe
how these images can be used to extract the collective mode dispersion of
anisotropic superconductors with sub-diffractional spatial resolution.Comment: 11 pages, 8 figure
Unicyclic Components in Random Graphs
The distribution of unicyclic components in a random graph is obtained
analytically. The number of unicyclic components of a given size approaches a
self-similar form in the vicinity of the gelation transition. At the gelation
point, this distribution decays algebraically, U_k ~ 1/(4k) for k>>1. As a
result, the total number of unicyclic components grows logarithmically with the
system size.Comment: 4 pages, 2 figure
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