6,128 research outputs found
Current status of metric reduction of (passive) scanner data
The extraction of metric information from scanner (particularly multispectral) data is presented. Data from both aircraft and spacecraft; singly scanned areas and areas with multiple coverage; various mathematical models used up to the present time; and published numerical results are considered. Future trends are also discussed
Coherent transport in Josephson-Junction rhombi chain with quenched disorder
We consider a chain of Josephson-junction rhombi (proposed originally by
Doucot and Vidal) in quantum regime. In a regular chain with no disorder in the
maximally frustrated case when magnetic flux through each rhombi \Phi_r is
equal to one half of superconductive flux quantum \Phi_0, Josephson current is
due to correlated transport of pairs of Cooper pairs, i.e. charge is quantized
in units of . Sufficiently strong deviation \delta\Phi =|\Phi_r-\Phi_0/2| >
\delta\Phi^c from the maximally frustrated point brings the system back to
usual -quantized supercurrent. For a regular chain \delta\Phi^c was
calculated by us previously. Here we present detailed analysis of the effect of
quenched disorder (random stray charges and random fluxes piercing rhombi) on
the pairing effect.Comment: 21 pages, 5 figure
Combining Full-Shape and BAO Analyses of Galaxy Power Spectra: A 1.6% CMB-independent constraint on H0
We present cosmological constraints from a joint analysis of the pre- and
post-reconstruction galaxy power spectrum multipoles from the final data
release of the Baryon Oscillation Spectroscopic Survey (BOSS). Geometric
constraints are obtained from the positions of BAO peaks in reconstructed
spectra, analyzed in combination with the unreconstructed spectra in a
full-shape (FS) likelihood using a joint covariance matrix, giving stronger
parameter constraints than FS-only or BAO-only analyses. We introduce a new
method for obtaining constraints from reconstructed spectra based on a
correlated theoretical error, which is shown to be simple, robust, and
applicable to any flavor of density-field reconstruction. Assuming CDM
with massive neutrinos, we analyze data from two redshift bins
and obtain constraints on the Hubble
constant , using only a single prior on the current baryon density
from Big Bang Nucleosynthesis (BBN) and no knowledge of the power
spectrum slope . This gives , with the inclusion of BAO
data sharpening the measurement by , representing one of the strongest
current constraints on independent of cosmic microwave background data.
Restricting to the best-fit slope from Planck (but without additional
priors on the spectral shape), we obtain a measurement of . We find strong constraints on the
cosmological parameters from a joint analysis of the FS, BAO, and Planck data.
This sets new bounds on the sum of neutrino masses (at confidence) and the effective number of
relativistic degrees of freedom , though
contours are not appreciably narrowed by the inclusion of BAO data.Comment: 42 pages, 12 figures, accepted by JCAP, likelihoods available at
https://github.com/Michalychforever/lss_montepython (minor typo corrected
Gauge theory approach to glass transitions
This theory combines a thermodynamic approach with a dynamic one in order to
describe glass transition. Glass transition is regarded as an inaccessible
second order phase transition, which is interrupted because of premature
critical slowing down, caused by the system's frustration. The
frustration-induced vortices are present in the structure besides
thermoactivated vortices, and prevent the development of the order parameter
fluctuations, that leads to the critical slowing down the system kinetics at
some temperature above the phase transition point
On the extra phase correction to the semiclassical spin coherent-state propagator
The problem of an origin of the Solary-Kochetov extra-phase contribution to
the naive semiclassical form of a generalized phase-space propagator is
addressed with the special reference to the su(2) spin case which is the most
important in applications. While the extra-phase correction to a flat
phase-space propagator can straightforwardly be shown to appear as a difference
between the principal and the Weyl symbols of a Hamiltonian in the
next-to-leading order expansion in the semiclassical parameter, the same
statement for the semiclassical spin coherent-state propagator holds provided
the Holstein-Primakoff representation of the su(2) algebra generators is
employed.Comment: 19 pages, no figures; a more general treatment is presented, some
references are added, title is slightly changed; submitted to JM
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