5,694 research outputs found
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
The Generalisability of the Stages and Processes of Change ; The Concurrent Validity of the Stages and Processes of Change
The transtheorctical model of behaviour change is comprised of the stages of change and the processes of change. The stages explain when change occurs, and the processes outline how change occurs. This model has been influential in clinical practice in the areas of tobacco smoking, alcohol use, eating disorders, and exercise behaviour. This review focuses on the previous literature concerned with the transtheorctical model. Although the model is popular and used to tailor interventions, it has not yet been cross-culturally vaildated, or tested comprehensively in the field of illegal drug use. Further research is necessary to examine whether or not the model is appropriate for use with different clinical populations
Long range order in non-equilibrium interacting quantum spin chains
We conjecture that non-equilibrium boundary conditions generically trigger
long range order in non-equilibrium steady states of locally interacting
quantum chains. Our result is based on large scale density matrix
renormalization group simulations of several models of quantum spin 1/2 chains
which are driven far from equilibrium by coupling to a pair of unequal Lindblad
reservoirs attached locally to the ends of the chain. In particular, we find a
phase transition from exponentially decaying to long range spin-spin
correlations in integrable Heisenberg XXZ chain by changing the anisotropy
parameter. Long range order also typically emerges after breaking the
integrability of the model.Comment: 4 pages, 4 figure
Quantum Clock Synchronization: a Multi-Party Protocol
We present a multi-party quantum clock synchronization protocol that utilizes
shared prior entanglement and broadcast of classical information to synchronize
spatially separated clocks. Notably, it is necessary only for any one party to
publish classical information. Consequently, the efficacy of the method is
independent of the relative location of the parties. The suggested protocol is
robust and does not require precise sequencing of procedural steps.Comment: 3 page
Sagnac effect in a chain of mesoscopic quantum rings
The ability to interferometrically detect inertial rotations via the Sagnac
effect has been a strong stimulus for the development of atom interferometry
because of the potential 10^{10} enhancement of the rotational phase shift in
comparison to optical Sagnac gyroscopes. Here we analyze ballistic transport of
matter waves in a one dimensional chain of N coherently coupled quantum rings
in the presence of a rotation of angular frequency, \Omega. We show that the
transmission probability, T, exhibits zero transmission stop gaps as a function
of the rotation rate interspersed with regions of rapidly oscillating finite
transmission. With increasing N, the transition from zero transmission to the
oscillatory regime becomes an increasingly sharp function of \Omega with a
slope \partialT/\partial \Omega N^2. The steepness of this slope dramatically
enhances the response to rotations in comparison to conventional single ring
interferometers such as the Mach-Zehnder and leads to a phase sensitivity well
below the standard quantum limit
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