120 research outputs found
1863-09-07 Dr. S.W. Chase states that Daniel R. Leathers is too ill to return from furlough
https://digitalmaine.com/cw_me_1st_heavy_corr/1117/thumbnail.jp
No hair for spherical black holes: charged and nonminimally coupled scalar field with self--interaction
We prove three theorems in general relativity which rule out classical scalar
hair of static, spherically symmetric, possibly electrically charged black
holes. We first generalize Bekenstein's no--hair theorem for a multiplet of
minimally coupled real scalar fields with not necessarily quadratic action to
the case of a charged black hole. We then use a conformal map of the geometry
to convert the problem of a charged (or neutral) black hole with hair in the
form of a neutral self--interacting scalar field nonminimally coupled to
gravity to the preceding problem, thus establishing a no--hair theorem for the
cases with nonminimal coupling parameter or . The
proof also makes use of a causality requirement on the field configuration.
Finally, from the required behavior of the fields at the horizon and infinity
we exclude hair of a charged black hole in the form of a charged
self--interacting scalar field nonminimally coupled to gravity for any .Comment: 30 pages, RevTeX. Sec.IV corrected, simplified and shortened.
Corrections to Sec.IIA between Eqs. 2.7 and Eq.2.1. First two paragraphs of
Sec. VC new. To appear Phys. Rev. D, Oct. 15, 199
Backward pion-nucleon scattering
A global analysis of the world data on differential cross sections and
polarization asymmetries of backward pion-nucleon scattering for invariant
collision energies above 3 GeV is performed in a Regge model. Including the
, , and trajectories, we
reproduce both angular distributions and polarization data for small values of
the Mandelstam variable , in contrast to previous analyses. The model
amplitude is used to obtain evidence for baryon resonances with mass below 3
GeV. Our analysis suggests a resonance with a mass of 2.83 GeV as
member of the trajectory from the corresponding Chew-Frautschi
plot.Comment: 12 pages, 16 figure
Three-Dimensional Gravity with Conformal Scalar and Asymptotic Virasoro Algebra
Strominger has derived the Bekenstein-Hawking entropy of the BTZ black hole
using asymptotic Virasoro algebra. We apply Strominger's method to a black hole
solution found by Martinez and Zanelli (MZ). This is a solution of
three-dimensional gravity with a conformal scalar field. The solution is not
, but it is asymptotically ; therefore, it has the asymptotic
Virasoro algebra. We compute the central charge for the theory and compares
Cardy's formula with the Bekenstein-Hawking entropy. It turns out that the
functional form does agree, but the overall numerical coefficient does not.
This is because this approach gives the "maximum possible entropy" for the
numerical coefficient.Comment: 26 pages, LaTeX; v2: minor correction
Radiation from the extremal black holes
The radiation from extreme Reissner-Nordstr\"{o}m black holes is computed by
explicitly considering the collapse of a spherical charged shell. No neutral
scalar radiation is found but there is emission of charged particles, provided
the charge to mass ratio be different from one. The absence of thermal effects
is in accord with the predictions of the euclidean theory but since the body
emits charged particles the entropy issue is not the same as for eternal
extreme black holes.Comment: 4 pages, LaTex, no figure
The Pattern of the Mineralization of Enamel
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68291/2/10.1177_00220345610400050101.pd
The current status of species recognition and identification in Aspergillus
The species recognition and identification of aspergilli and their
teleomorphs is discussed. A historical overview of the taxonomic concepts
starting with the monograph of Raper & Fennell
(1965) is given. A list of
taxa described since 2000 is provided. Physiological characters, particularly
growth rates and the production of extrolites, often show differences that
reflect phylogenetic species boundaries and greater emphasis should be placed
on extrolite profiles and growth characteristics in species descriptions.
Multilocus sequence-based phylogenetic analyses have emerged as the primary
tool for inferring phylogenetic species boundaries and relationships within
subgenera and sections. A four locus DNA sequence study covering all major
lineages in Aspergillus using genealogical concordance theory
resulted in a species recognition system that agrees in part with phenotypic
studies and reveals the presence of many undescribed species not resolved by
phenotype. The use of as much data from as many sources as possible in making
taxonomic decisions is advocated. For species identification, DNA barcoding
uses a short genetic marker in an organism”s DNA to quickly and easily
identify it to a particular species. Partial cytochrome oxidase subunit 1
sequences, which are used for barcoding animal species, were found to have
limited value for species identification among black aspergilli. The various
possibilities are discussed and at present partial β-tubulin or
calmodulin are the most promising loci for Aspergillus
identification. For characterising Aspergillus species one
application would be to produce a multilocus phylogeny, with the goal of
having a firm understanding of the evolutionary relationships among species
across the entire genus. DNA chip technologies are discussed as possibilities
for an accurate multilocus barcoding tool for the genus
Aspergillus
Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society
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