8,004 research outputs found
Discussion of: A statistical analysis of multiple temperature proxies: Are reconstructions of surface temperatures over the last 1000 years reliable?
Discussion of "A statistical analysis of multiple temperature proxies: Are
reconstructions of surface temperatures over the last 1000 years reliable?" by
B.B. McShane and A.J. Wyner [arXiv:1104.4002]Comment: Published in at http://dx.doi.org/10.1214/10-AOAS398F the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The price of being SM-like in SUSY
We compute the tuning in supersymmetric models associated with the
constraints from collider measurements of the Higgs couplings to fermions and
gauge bosons. In supersymmetric models, a CP-even state with SM Higgs couplings
mixes with additional, heavier CP-even states, causing deviations in the Higgs
couplings from SM values. These deviations are reduced as the heavy states are
decoupled with large soft masses, thereby exacerbating the tuning associated
with the electroweak scale. This new source of tuning is different from that
derived from collider limits on stops, gluinos and Higgsinos. It can be offset
with large tan beta in the MSSM, however this compensating effect is limited in
the NMSSM with a large Higgs-singlet coupling due to restrictions on large tan
beta from electroweak precision tests. We derive a lower bound on this tuning
and show that the level of precision of Higgs coupling measurements at the LHC
will probe naturalness in the NMSSM at the few-percent level. This is
comparable to the tuning derived from superpartner limits in models with a low
messenger scale and split families. Instead the significant improvement in
sensitivity of Higgs coupling measurements at the ILC will allow naturalness in
these models to be constrained at the per-mille level, beyond any tuning
derived from direct superpartner limits.Comment: 29 pages, 6 figure
Design and performance of controlled-diffusion stator compared with original double-circular-arc stator
The capabilities of two stators, one with controlled-diffusion (CD) blade sections and one with double-circular-arc (DCA) blade sections, were compared. A CD stator was designed and tested that had the same chord length but half the blades of the DCA stator. The same fan rotor (tip speed, 429 m/sec; pressure ratio, 1.65) was used with each stator row. The design and analysis system is briefly described. The overall stage and rotor performances with each stator are compared, as are selected blade element data. The minimum overall efficiency decrement across the stator was approximately 1 percentage point greater with the CD balde sections than with the DCA blade sections
Cosmic Shear Results from the Deep Lens Survey - II: Full Cosmological Parameter Constraints from Tomography
We present a tomographic cosmic shear study from the Deep Lens Survey (DLS),
which, providing a limiting magnitude r_{lim}~27 (5 sigma), is designed as a
pre-cursor Large Synoptic Survey Telescope (LSST) survey with an emphasis on
depth. Using five tomographic redshift bins, we study their auto- and
cross-correlations to constrain cosmological parameters. We use a
luminosity-dependent nonlinear model to account for the astrophysical
systematics originating from intrinsic alignments of galaxy shapes. We find
that the cosmological leverage of the DLS is among the highest among existing
>10 sq. deg cosmic shear surveys. Combining the DLS tomography with the 9-year
results of the Wilkinson Microwave Anisotropy Probe (WMAP9) gives
Omega_m=0.293_{-0.014}^{+0.012}, sigma_8=0.833_{-0.018}^{+0.011},
H_0=68.6_{-1.2}^{+1.4} km/s/Mpc, and Omega_b=0.0475+-0.0012 for LCDM, reducing
the uncertainties of the WMAP9-only constraints by ~50%. When we do not assume
flatness for LCDM, we obtain the curvature constraint
Omega_k=-0.010_{-0.015}^{+0.013} from the DLS+WMAP9 combination, which however
is not well constrained when WMAP9 is used alone. The dark energy equation of
state parameter w is tightly constrained when Baryonic Acoustic Oscillation
(BAO) data are added, yielding w=-1.02_{-0.09}^{+0.10} with the DLS+WMAP9+BAO
joint probe. The addition of supernova constraints further tightens the
parameter to w=-1.03+-0.03. Our joint constraints are fully consistent with the
final Planck results and also the predictions of a LCDM universe.Comment: Accepted for publication in Ap
Counting Nilpotent Pairs in Finite Groups: Some Conjectures
The number of nilpotent pairs is determined for a number of small groups
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