10,267 research outputs found
Galaxy clustering with photometric surveys using PDF redshift information
Photometric surveys produce large-area maps of the galaxy distribution, but
with less accurate redshift information than is obtained from spectroscopic
methods. Modern photometric redshift (photo-z) algorithms use galaxy
magnitudes, or colors, that are obtained through multi-band imaging to produce
a probability density function (PDF) for each galaxy in the map. We used
simulated data to study the effect of using different photo-z estimators to
assign galaxies to redshift bins in order to compare their effects on angular
clustering and galaxy bias measurements. We found that if we use the entire
PDF, rather than a single-point (mean or mode) estimate, the deviations are
less biased, especially when using narrow redshift bins. When the redshift bin
widths are , the use of the entire PDF reduces the typical
measurement bias from 5%, when using single point estimates, to 3%.Comment: Matches the MNRAS published version. 19 pages, 19 Figure
Synchronization of interconnected networks: the role of connector nodes
In this Letter we identify the general rules that determine the
synchronization properties of interconnected networks. We study analytically,
numerically and experimentally how the degree of the nodes through which two
networks are connected influences the ability of the whole system to
synchronize. We show that connecting the high-degree (low-degree) nodes of each
network turns out to be the most (least) effective strategy to achieve
synchronization. We find the functional relation between synchronizability and
size for a given network-of-networks, and report the existence of the optimal
connector link weights for the different interconnection strategies. Finally,
we perform an electronic experiment with two coupled star networks and conclude
that the analytical results are indeed valid in the presence of noise and
parameter mismatches.Comment: Accepted for publication in Physical Review Letters. Main text: 5
pages, 4 figures. Supplemental material: 8 pages, 3 figure
La aplicación de los gráficos en la didáctica de la traducción cientÃfico-técnica.
Los gráficos como sistema de transmisión de ideas cobran una especial importancia en el lenguaje cientÃfico-técnico, pues su utilización simplifica y cIarifica la comunicación cuando la información es compleja. El traductor que se enfrenta a textos con gráficos puede valerse de ellos para comprender mejor el texto. Del mismo modo, el profesor de traducción cientÃfico-técnica puede emplear los gráficos en la clase para hacer más claras las explicaciones y mejorar la comprensión por parte del alumnado.Graphics as a system of transmission of ideas takes a special importance in the scientific and technical language, since its use makes communication easier and clearer when information is complex. The transÃator who faces texts with graphics can take advantage of them for a better comprehension of the text. In the same way, the teacher of scientific and technical transÃation can use the graphics in class ir make te explanations clearer and improve the comprehension of the students. 145 Manuel Sevilla Mullos La aplicación de los gráficos en la didáctica de la traducción... Julia Sevilla Muño
A class of Hamilton-Jacobi equations on Banach-Finsler manifolds
The concept of subdifferentiability is studied in the context of
Finsler manifolds (modeled on a Banach space with a Lipschitz bump
function). A class of Hamilton-Jacobi equations defined on Finsler
manifolds is studied and several results related to the existence and
uniqueness of viscosity solutions are obtained.Comment: 24 page
Harmonically Trapped Quantum Gases
We solve the problem of a Bose or Fermi gas in -dimensions trapped by mutually perpendicular harmonic oscillator potentials. From the
grand potential we derive their thermodynamic functions (internal energy,
specific heat, etc.) as well as a generalized density of states. The Bose gas
exhibits Bose-Einstein condensation at a nonzero critical temperature
if and only if , and a jump in the specific heat at if and
only if . Specific heats for both gas types precisely coincide as
functions of temperature when . The trapped system behaves like an
ideal free quantum gas in dimensions. For we recover
all known thermodynamic properties of ideal quantum gases in dimensions,
while in 3D for 1, 2 and 3 one simulates behavior reminiscent of
quantum {\it wells, wires}and{\it dots}, respectively.Comment: 14 pages including 3 figures and 3 table
Electrochemical reduction of carbamazepine in ethanol and water solutions using a glassy carbon electrode
The electrochemical reduction of carbamazepine in ethanol and water using a glassy carbon electrode has been studied. In all experimental conditions of scan rate and concentration of carbamazepine an irreversible cathodic wave was observed by cyclic voltammetry (CV). Electrochemical parameters and a plausible EqC mechanism have been reported from the electrochemical measurements and digital simulation. The values of thermodynamic E1/2 were correlated with solvent polarity parameters that it can be interesting for biological, pharmaceutical and forensic purposes. Limits of Detection (LOD) for DPV are 1.1 and 9.0 g/mL (4.65x10-6 and 3.81x10-5 M) in ethanol and water, respectively. The precision and recoveries obtained for tablets and plasma samples showed that the method could be successfully used for analysis
Cooper pairs as bosons
Although BCS pairs of fermions are known not to obey Bose-Einstein (BE)
commutation relations nor BE statistics, we show how Cooper pairs (CPs),
whether the simple original ones or the CPs recently generalized in a many-body
Bethe-Salpeter approach, being clearly distinct from BCS pairs at least obey BE
statistics. Hence, contrary to widespread popular belief, CPs can undergo BE
condensation to account for superconductivity if charged, as well as for
neutral-atom fermion superfluidity where CPs, but uncharged, are also expected
to form.Comment: 8 pages, 2 figures, full biblio info adde
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