595,089 research outputs found

### An adaptive significance threshold criterion for massive multiple hypotheses testing

This research deals with massive multiple hypothesis testing. First regarding
multiple tests as an estimation problem under a proper population model, an
error measurement called Erroneous Rejection Ratio (ERR) is introduced and
related to the False Discovery Rate (FDR). ERR is an error measurement similar
in spirit to FDR, and it greatly simplifies the analytical study of error
properties of multiple test procedures. Next an improved estimator of the
proportion of true null hypotheses and a data adaptive significance threshold
criterion are developed. Some asymptotic error properties of the significant
threshold criterion is established in terms of ERR under distributional
assumptions widely satisfied in recent applications. A simulation study
provides clear evidence that the proposed estimator of the proportion of true
null hypotheses outperforms the existing estimators of this important parameter
in massive multiple tests. Both analytical and simulation studies indicate that
the proposed significance threshold criterion can provide a reasonable balance
between the amounts of false positive and false negative errors, thereby
complementing and extending the various FDR control procedures. S-plus/R code
is available from the author upon request.Comment: Published at http://dx.doi.org/10.1214/074921706000000392 in the IMS
Lecture Notes--Monograph Series
(http://www.imstat.org/publications/lecnotes.htm) by the Institute of
Mathematical Statistics (http://www.imstat.org

### Advance in dynamical spontaneous symmetry breaking

Recently, a condition is derived for a nontrivial solution of the
Schwinger-Dyson equation to be accompanied by a Goldstone bound state in a
special quantum electrodynamics model. This result is extended and a new form
of the Goldstone theorem is obtained in a general quantum field theory
framework.Comment: 3 pages, LaTeX, no figure

### Anomalous Dimension in the Solution of the Barenblatt's Equation

A new method is presented to obtain the anomalous dimension in the solution
of the Barenblatt's equation. The result is the same as that in the
renormalization group (RG) approach. It gives us insight on the perturbative
solution of the Barenblatt's equation in the RG approach. Based on this
discussion, an improvement is made to take into account, in more complete way,
the nonlinear effect, which is included in the Heaviside function in higher
orders. This improved result is better than that in RG approach.Comment: 17 pages, LaTex, no figur

### Penguin-induced Radiative Baryonic B Decays Revisited

Weak radiative baryonic B decays $\bar B\to B_1\bar B_2\gamma$ mediated by
the electromagnetic penguin process $b\to s\gamma$ are re-examined within the
framework of the pole model. The meson pole contribution that has been
neglected before is taken into account in this work. It is found that the
intermediate $K^*$ contribution dominates in the $\Sigma\bar p\gamma$ mode and
is comparable to the baryon pole effect in $\Lambda\bar p\gamma$ and
$\Xi\bar\Lambda\gamma$ modes. The branching ratios for $B^-\to\Lambda\bar
p\gamma$ and $B^-\to\Xi^0\bar\Sigma^-\gamma$ are of order $2.6\times 10^{-6}$
and $6\times 10^{-7}$, respectively. The threshold enhancement effect in the
dibaryon mass spectrum is responsible by the meson pole diagram. We also study
the angular distribution of the baryon in the dibaryon rest frame. The baryon
pole diagrams imply that the antibaryon tends to emerge in the direction of the
photon in the baryon-pair rest frame. The predicted angular asymmetry agrees
with experiment for $B^-\to\Lambda\bar p\gamma$. Measurements of the
correlation of the photon with the baryon allow us to discriminate between
different models for describing the radiative baryonic B decays. For decays
$B\to\Xi\bar\Sigma\gamma$, a large correlation of the photon to the
$\bar\Sigma$ and a broad bump in the dibaryon mass spectrum are predicted.Comment: 10 pages, 4 figure

### Kostant homology formulas for oscillator modules of Lie superalgebras

We provide a systematic approach to obtain formulas for characters and
Kostant ${\mathfrak u}$-homology groups of the oscillator modules of the finite
dimensional general linear and ortho-symplectic superalgebras, via Howe
dualities for infinite dimensional Lie algebras. Specializing these Lie
superalgebras to Lie algebras, we recover, in a new way, formulas for Kostant
homology groups of unitarizable highest weight representations of Hermitian
symmetric pairs. In addition, two new reductive dual pairs related to the
above-mentioned ${\mathfrak u}$-homology computation are worked out

### Collapsing strange quark matter in Vaidya geometry

Exact solutions of the gravitational field equations for a mixture of a null
charged strange quark fluid and radiation are obtained in a Vaidya space-time.
The conditions for the formation of a naked singularity are analyzed by
considering the behavior of radial geodesics originating from the central
singularity.Comment: 6 pages, no figure

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