380,647 research outputs found
The Lyman <span class='mathrm'>α</span> and Lyman <span class='mathrm'>β</span> lines in solar coronal streamers
No abstract available
Symmetry breaking and manipulation of nonlinear optical modes in an asymmetric double-channel waveguide
We study light-beam propagation in a nonlinear coupler with an asymmetric
double-channel waveguide and derive various analytical forms of optical modes.
The results show that the symmetry-preserving modes in a symmetric
double-channel waveguide are deformed due to the asymmetry of the two-channel
waveguide, yet such a coupler supports the symmetry-breaking modes. The
dispersion relations reveal that the system with self-focusing nonlinear
response supports the degenerate modes, while for self-defocusingmedium the
degenerate modes do not exist. Furthermore, nonlinear manipulation is
investigated by launching optical modes supported in double-channel waveguide
into a nonlinear uniform medium.Comment: 10 page
Are Tidal Effects Responsible for Exoplanetary Spin-Orbit Alignment?
The obliquities of planet-hosting stars are clues about the formation of
planetary systems. Previous observations led to the hypothesis that for
close-in giant planets, spin-orbit alignment is enforced by tidal interactions.
Here, we examine two problems with this hypothesis. First, Mazeh and coworkers
recently used a new technique -- based on the amplitude of starspot-induced
photometric variability -- to conclude that spin-orbit alignment is common even
for relatively long-period planets, which would not be expected if tides were
responsible. We re-examine the data and find a statistically significant
correlation between photometric variability and planetary orbital period that
is qualitatively consistent with tidal interactions. However it is still
difficult to explain quantitatively, as it would require tides to be effective
for periods as long as tens of days. Second, Rogers and Lin argued against a
particular theory for tidal re-alignment by showing that initially retrograde
systems would fail to be re-aligned, in contradiction with the observed
prevalence of prograde systems. We investigate a simple model that overcomes
this problem by taking into account the dissipation of inertial waves and the
equilibrium tide, as well as magnetic braking. We identify a region of
parameter space where re-alignment can be achieved, but it only works for
close-in giant planets, and requires some fine tuning. Thus, while we find both
problems to be more nuanced than they first appeared, the tidal model still has
serious shortcomings.Comment: 12 pages, 9 figures. Accepted for publication in Ap
Surface-wave solitons on the interface between a linear medium and a nonlocal nonlinear medium
We address the properties of surface-wave solitons on the interface between a
semi-infinite homogeneous linear medium and a semi-infinite homogeneous
nonlinear nonlocal medium. The stability, energy flow and FWHM of the surface
wave solitons can be affected by the degree of nonlocality of the nonlinear
medium. We find that the refractive index difference affects the power
distribution of the surface solitons in two media. We show that the different
boundary values at the interface can lead to the different peak position of the
surface solitons, but it can not influence the solitons stability with a
certain degree of nonlocality.Comment: 8 pages, 14 figures, 15 references, and so o
Next-to-leading order QCD effects in associated charged Higgs and W boson production in the MSSM at the CERN Large Hadron Collider
We present the calculations of the next-to-leading order (NLO) QCD
corrections to the inclusive total cross sections for the associated production
of the through annihilation in the Minimal
Supersymmetric Standard Model at the CERN Large Hadron Collider. The NLO QCD
corrections can either enhance or reduce the total cross sections, but they
generally efficiently reduce the dependence of the total cross sections on the
renormalization/factorization scale. The magnitude of the NLO QCD corrections
is about 10% in most of the parameter space and can reach 15% in some parameter
regions. We also show the Monte Carlo simulation results for the
signature from the and the
decays including the NLO QCD effects, and find an observable signal at a
level in some parameter region of the minimal supergravity model.Comment: version to be published in Phys.Rev.
Operators between subspaces and quotients of L1
We provide an unified approach of results of L. Dor on the complementation of
the range, and of D. Alspach on the nearness from isometries, of small into
isomorphisms of L1. We introduce the notion of small subspace of L1 and show
lifting theorems for operators between quotients of L1 by small subspaces. We
construct a subspace of L1 which shows that extension of isometries from
subspaces of L1 to the whole space are no longer true for isomorphisms, and
that nearly isometric isomorphisms from subspaces of L1 into L1 need not be
near from any isometry.Comment: 35 page
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