8,053,070 research outputs found
Iterated Differential Forms IV: C-Spectral Sequence
For the multiple differential algebra of iterated differential forms (see
math.DG/0605113 and math.DG/0609287) on a diffiety (O,C) an analogue of
C-spectral sequence is constructed. The first term of it is naturally
interpreted as the algebra of secondary iterated differential forms on (O,C).
This allows to develop secondary tensor analysis on generic diffieties, some
simplest elements of which are sketched here. The presented here general theory
will be specified to infinite jet spaces and infinitely prolonged PDEs in
subsequent notes.Comment: 8 pages, submitted to Math. Dok
Operator-Schmidt decomposition of the quantum Fourier transform on C^N1 tensor C^N2
Operator-Schmidt decompositions of the quantum Fourier transform on C^N1
tensor C^N2 are computed for all N1, N2 > 1. The decomposition is shown to be
completely degenerate when N1 is a factor of N2 and when N1>N2. The first known
special case, N1=N2=2^n, was computed by Nielsen in his study of the
communication cost of computing the quantum Fourier transform of a collection
of qubits equally distributed between two parties. [M. A. Nielsen, PhD Thesis,
University of New Mexico (1998), Chapter 6, arXiv:quant-ph/0011036.] More
generally, the special case N1=2^n1<2^n2=N2 was computed by Nielsen et. al. in
their study of strength measures of quantum operations. [M.A. Nielsen et. al,
(accepted for publication in Phys Rev A); arXiv:quant-ph/0208077.] Given the
Schmidt decompositions presented here, it follows that in all cases the
communication cost of exact computation of the quantum Fourier transform is
maximal.Comment: 9 pages, LaTeX 2e; No changes in results. References and
acknowledgments added. Changes in presentation added to satisfy referees:
expanded introduction, inclusion of ommitted algebraic steps in the appendix,
addition of clarifying footnote
Allelic Frequency of Kappa-Casein Locus (Asp148/Ala) in F1: Simmental (Bos Taurus) X Ongole Grade (Bos Indicus)
This study was conducted to detect the genetic variants (single nucleotide polymorphism) of kappa-casein locus (Asp148/Ala) in F1: Simmental (Bos taurus) x Ongole grade (Bos indicus), SIMPO. Genomic DNA was isolated from blood sample of 40 SIMPO (21 males and 19 females). A 780 bp specific fragment of kappa-casein gene spanning from the forth exon region (517 bp) to forth intron (263 bp) was successfully amplified. The result of the PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphisms) analysis using HindIII enzyme showed that two genotypes (AA and AB) were found at this locus in SIMPO. The frequencies of A and B alleles in SIMPO were 0.79 and 0.21, respectively. The frequency lies between B. taurus (Simmental) and B. indicus group
Giant oscillations of the current in a dirty 2D electron system flowing perpendicular to a lateral barrier under magnetic field
The charge transport in a dirty 2-dimensional electron system biased in the
presence of a lateral potential barrier under magnetic field is theoretically
studied. The quantum tunneling across the barrier provides the quantum
interference of the edge states localized on its both sides that results in
giant oscillations of the charge current flowing perpendicular to the lateral
junction. Our theoretical analysis is in a good agreement with the experimental
observations presented in Ref.8. In particular, positions of the conductance
maxima coincide with the Landau levels while the conductance itself is
essentially suppressed even at the energies at which the resonant tunneling
occurs and hence these puzzling observations can be resolved without taking
into account the electron-electron interaction.Comment: 6 pages, 4 figure
Automated novelty detection in the WISE survey with one-class support vector machines
Wide-angle photometric surveys of previously uncharted sky areas or
wavelength regimes will always bring in unexpected sources whose existence and
properties cannot be easily predicted from earlier observations: novelties or
even anomalies. Such objects can be efficiently sought for with novelty
detection algorithms. Here we present an application of such a method, called
one-class support vector machines (OCSVM), to search for anomalous patterns
among sources preselected from the mid-infrared AllWISE catalogue covering the
whole sky. To create a model of expected data we train the algorithm on a set
of objects with spectroscopic identifications from the SDSS DR13 database,
present also in AllWISE. OCSVM detects as anomalous those sources whose
patterns - WISE photometric measurements in this case - are inconsistent with
the model. Among the detected anomalies we find artefacts, such as objects with
spurious photometry due to blending, but most importantly also real sources of
genuine astrophysical interest. Among the latter, OCSVM has identified a sample
of heavily reddened AGN/quasar candidates distributed uniformly over the sky
and in a large part absent from other WISE-based AGN catalogues. It also
allowed us to find a specific group of sources of mixed types, mostly stars and
compact galaxies. By combining the semi-supervised OCSVM algorithm with
standard classification methods it will be possible to improve the latter by
accounting for sources which are not present in the training sample but are
otherwise well-represented in the target set. Anomaly detection adds
flexibility to automated source separation procedures and helps verify the
reliability and representativeness of the training samples. It should be thus
considered as an essential step in supervised classification schemes to ensure
completeness and purity of produced catalogues.Comment: 14 pages, 15 figure
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