69 research outputs found
Lensing in an interior Kottler solution
We derive the interior Kottler solution of the incompressible fluid and show
that the bending of light in this solution does depend on the cosmological
constant.Comment: The inner Kottler solution derived and used in this paper is not new.
Corresponding references to Stuchlik (2000) and Boehmer (2003) are added.
Also added: a numerical example and a figure. This is the version accepted by
Gen. Rel. Grav. However it includes a short passage that an anonymous referee
had me suppress
Fuzzy Mass Relations for the Higgs
The non-commutative approach of the standard model produces a relation
between the top and the Higgs masses. We show that, for a given top mass, the
Higgs mass is constrained to lie in an interval. The length of this interval is
of the order of .Comment: 26 pages, LaTe
On a weak Gauss law in general relativity and torsion
We present an explicit example showing that the weak Gauss law of general
relativity (with cosmological constant) fails in Einstein-Cartan's theory. We
take this as an indication that torsion might replace dark matter.Comment: 10 pages. Version 2 corrects a factor 3 in Cartan's equations to
become
Almost-Commutative Geometries Beyond the Standard Model
In [7-9] and [10] the conjecture is presented that almost-commutative
geometries, with respect to sensible physical constraints, allow only the
standard model of particle physics and electro-strong models as
Yang-Mills-Higgs theories. In this publication a counter example will be given.
The corresponding almost-commutative geometry leads to a Yang-Mills-Higgs
model which consists of the standard model of particle physics and two new
fermions of opposite electro-magnetic charge. This is the second
Yang-Mills-Higgs model within noncommutative geometry, after the standard
model, which could be compatible with experiments. Combined to a hydrogen-like
composite particle these new particles provide a novel dark matter candidate
Genome-wide SNP typing of ancient DNA: Determination of hair and eye color of Bronze Age humans from their skeletal remains.
Objective A genome-wide high-throughput single nucleotide polymorphism (SNP) typing method was tested with respect of the applicability to ancient and degraded DNA. The results were compared to mini-sequencing data achieved through single base extension (SBE) typing. The SNPs chosen for the study allow to determine the hair colors and eye colors of humans. Material and methods The DNA samples were extracted from the skeletal remains of 59 human individuals dating back to the Late Bronze Age. The 3,000 years old bones had been discovered in the Lichtenstein Cave in Lower Saxony, Germany. The simultaneous typing of 24 SNPs for each of the ancient DNA samples was carried out using the 192.24 Dynamic Array (TM) by Fluidigm (R). Results Thirty-eight of the ancient samples (=64%) revealed full and reproducible SNP genotypes allowing hair and eye color phenotyping. In 10 samples (=17%) at least half of the SNPs were unambiguously determined, in 11 samples (=19%) the SNP typing failed. For 23 of the 59 individuals, a comparison of the SNP typing results with genotypes from an earlier performed SBE typing approach was possible. The comparison confirmed the full concordance of the results for 90% of the SNP typings. In the remaining 10% allelic dropouts were identified. Discussion The high genotyping success rate could be achieved by introducing modifications to the preamplification protocol mainly by increasing the DNA input and the amplification cycle number. The occurrence of allelic dropouts indicates that a further increase of DNA input to the preamplification step is desirable
Moyal Planes are Spectral Triples
Axioms for nonunital spectral triples, extending those introduced in the
unital case by Connes, are proposed. As a guide, and for the sake of their
importance in noncommutative quantum field theory, the spaces endowed
with Moyal products are intensively investigated. Some physical applications,
such as the construction of noncommutative Wick monomials and the computation
of the Connes--Lott functional action, are given for these noncommutative
hyperplanes.Comment: Latex, 54 pages. Version 3 with Moyal-Wick section update
Cosmological constant and time delay
The effect of the cosmological constant on the time delay caused by an
isolated spherical mass is calculated without using the lens equation and
compared to a recent observational bound on the time delay of the lensed quasar
SDSS J1004+4112.Comment: 8 pages, 1 figur
Time delay in the Einstein-Straus solution
The time delay of strong lensing is computed in the framework of the
Einstein-Straus solution. The theory is compared to the observational bound on
the time delay of the lens SDSS J1004+4112.Comment: 20 pages, 4 tables, 1 figur
Cosmic Mass Functions from Gaussian Stochastic Diffusion Processes
Gaussian stochastic diffusion processes are used to derive cosmic mass functions. To get analytic relations previous studies exploited the sharp -space filter assumption yielding zero drift terms in the corresponding Fokker-Planck (Kolmogorov's forward) equation and thus simplifying analytic treatments significantly (excursion set formalism). In the present paper methods are described to derive for given diffusion processes and Gaussian random fields the corresponding mass and filter functions by solving the Kolmogorov's forward and backward equations including nonzero drift terms. This formalism can also be used in cases with non-sharp -space filters and for diffusion processes exhibiting correlations between different mass scales
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