5,674,097 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
Glycerol as an Energy Source for Ruminants: a Meta-Analysis of in Vitro Experiments
Glycerol or glycerin is generally recognized as a safe compound to be used in animal feed, especially for ruminants. A number of in vitro studies related to glycerol supplementation in ruminant ration have been published but to date the results have not been summarized. The objective of this study was, therefore, to evaluate in vitro digestibility, ruminal fermentation characteristics, total gas and methane production through the meta-analysis approach. Meta-analysis was applied to 13 experiments and 42 treatments dealing with glycerol supplementation in ruminants. Data were analyzed by general linear model procedure in which the glycerol levels and the different studies were treated as fixed effects. Results revealed that glycerol supplementation did not affect the in vitro digestibility and total VFA production, but significantly decreased molar proportion of acetate and iso-valerate (P<0.05). In contrast, molar proportion of propionate, butyrate, and valerate significantly increased, and thus the ratio of acetate to propionate declined linearly (P<0.05). Methane production decreased linearly and accompanied with an increase of total gas production with increasing levels of glycerol supplementation (P<0.05). It is concluded that the use of glycerol as an energy substitution in animal feed has no detrimental effects in the rumen and environmentally friendly
Dipole-Quadrupole Theory of Surface Enhanced Infrared Absorption and Appearance of Forbidden Lines in the SEIRA Spectra of Symmetrical Molecules
The paper presents main aspects of the Dipole-Quadrupole theory of Surface
Enhanced Infrared Absorption (SEIRA). It is pointed out the possibility of
appearance of the lines, caused by totally symmetric vibrations transforming
after the unit irreducible representation, which are forbidden in usual
infrared absorption spectra in molecules with sufficiently high symmetry.
Observation of such lines in the SEIRA spectra of diprotonated and ethylene,
adsorbed on and on mordenites is pointed out. The results well agree with our
ideas about surface enhanced optical processes, based on the conception of a
strong quadrupole light-molecule interaction, which allows us to develop the
SERS and SEHRS theories.Comment: 15 pages,3 figures, 1 tabl
On the initial condition for evolution of the perturbative QCD Pomeron in the nucleus
It is shown that subdominant terms found in the reggeized gluon diagram
technique, to be added to Pomeron fan diagrams with the 3P interaction, can be
exactly taken into account by taking the initial condition for evolution in the
Glauber form. This demonstrates complete equivalence of the dipole picture and
the reggeized gluon approach not only on the leading level but also on the
subleading level.Comment: 5 pages in LaTe
2 and 3-dimensional Hamiltonians with Shape Invariance Symmetry
Via a special dimensional reduction, that is, Fourier transforming over one
of the coordinates of Casimir operator of su(2) Lie algebra and 4-oscillator
Hamiltonian, we have obtained 2 and 3 dimensional Hamiltonian with shape
invariance symmetry. Using this symmetry we have obtained their eigenspectrum.
In the mean time we show equivalence of shape invariance symmetry and Lie
algebraic symmetry of these Hamiltonians.Comment: 24 Page
Massive Fields of Arbitrary Integer Spin in Symmetrical Einstein Space
We study the propagation of gauge fields with arbitrary integer spins in the
symmetrical Einstein space of any dimensionality. We reduce the problem of
obtaining a gauge-invariant Lagrangian of integer spin fields in such
background to an purely algebraic problem of finding a set of operators with
certain features using the representation of high-spin fields in the form of
some vectors of pseudo-Hilbert space. We consider such construction in the
linear order in the Riemann tensor and scalar curvature and also present an
explicit form of interaction Lagrangians and gauge transformations for massive
particles with spins 1 and 2 in terms of symmetrical tensor fields.Comment: 15 pages, latex, no figures,minor change
On Chebyshev polynomials and torus knots
In this work we demonstrate that the q-numbers and their two-parameter
generalization, the q,p-numbers, can be used to obtain some polynomial
invariants for torus knots and links. First, we show that the q-numbers, which
are closely connected with the Chebyshev polynomials, can also be related with
the Alexander polynomials for the class T(s,2) of torus knots, s being an odd
integer, and used for finding the corresponding skein relation. Then, we
develop this procedure in order to obtain, with the help of q,p-numbers, the
generalized two-variable Alexander polynomials, and prove their direct
connection with the HOMFLY polynomials and the skein relation of the latter.Comment: 6 pages (two-column UJP style
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
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