28 research outputs found
Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star
A search of the time-series photometry from NASA's Kepler spacecraft reveals
a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626
with a period of 290 days. The characteristics of the host star are well
constrained by high-resolution spectroscopy combined with an asteroseismic
analysis of the Kepler photometry, leading to an estimated mass and radius of
0.970 +/- 0.060 MSun and 0.979 +/- 0.020 RSun. The depth of 492 +/- 10ppm for
the three observed transits yields a radius of 2.38 +/- 0.13 REarth for the
planet. The system passes a battery of tests for false positives, including
reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A
full BLENDER analysis provides further validation of the planet interpretation
by showing that contamination of the target by an eclipsing system would rarely
mimic the observed shape of the transits. The final validation of the planet is
provided by 16 radial velocities obtained with HIRES on Keck 1 over a one year
span. Although the velocities do not lead to a reliable orbit and mass
determination, they are able to constrain the mass to a 3{\sigma} upper limit
of 124 MEarth, safely in the regime of planetary masses, thus earning the
designation Kepler-22b. The radiative equilibrium temperature is 262K for a
planet in Kepler-22b's orbit. Although there is no evidence that Kepler-22b is
a rocky planet, it is the first confirmed planet with a measured radius to
orbit in the Habitable Zone of any star other than the Sun.Comment: Accepted to Ap
The boomerang effect of radicalism in Discursive Psychology: A critical overview of the controversy with the Social Representations Theory.
This article provides a critical overview of the controversy between the Radical approach to Discursive Psychology (RDP) and the Social Representations Theory (SRT) and aims: a)?to show what is potentially complementary and contradictory in Discursive Psychology (DP) and the Social Representations Theory, when and why they are incompatible, and whether and how it is possible and/or desirable to integrate these two approaches. b)?to describe how the radicalism of the socio-constructionist thesis upheld by Discourse Analysis can give rise to several hard-to-solve problems, which may then be translated into a boomerang effect. In the final section, it highlights interest in dialog and “cross-fertilization” between researchers inspired by the less radical approach to discursive psychology and those inspired by the Social Representations Theory, pointing out the effect of methodological implications that would ensue
Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
We present the first results of the Fermilab Muon g-2 Experiment for the
positive muon magnetic anomaly . The anomaly is
determined from the precision measurements of two angular frequencies.
Intensity variation of high-energy positrons from muon decays directly encodes
the difference frequency between the spin-precession and cyclotron
frequencies for polarized muons in a magnetic storage ring. The storage ring
magnetic field is measured using nuclear magnetic resonance probes calibrated
in terms of the equivalent proton spin precession frequency
in a spherical water sample at 34.7C. The
ratio , together with known fundamental
constants, determines
(0.46\,ppm). The result is 3.3 standard deviations greater than the standard
model prediction and is in excellent agreement with the previous Brookhaven
National Laboratory (BNL) E821 measurement. After combination with previous
measurements of both and , the new experimental average of
(0.35\,ppm) increases the
tension between experiment and theory to 4.2 standard deviationsComment: 10 pages; 4 figure
On generalized semi-infinite programming
Generalized semi-infinite programming, extended Mangasarian-Fromovitz, Kuhn-Tucker and Abadie constraint qualification, Fritz-John condition, first and second order optimality conditions, optimal value function, directional differentiability, second order epiregularity, second order growth condition, 90C34, 90C30, 90C46, 65K05,