11,679 research outputs found
The Pioneer Anomaly and a Machian Universe
We discuss astronomical and astrophysical evidence, which we relate to the
principle of zero-total energy of the Universe, that imply several relations
among the mass M, the radius R and the angular momentum L of a "large" sphere
representing a Machian Universe. By calculating the angular speed, we find a
peculiar centripetal acceleration for the Universe. This is an ubiquituous
property that relates one observer to any observable. It turns out that this is
exactly the anomalous acceleration observed on the Pioneers spaceships. We have
thus, shown that this anomaly is to be considered a property of the Machian
Universe. We discuss several possible arguments against our proposal.Comment: 6 pages including front page. Publishe
Formal and finite order equivalences
We show that two families of germs of real-analytic subsets in are
formally equivalent if and only if they are equivalent of any finite order. We
further apply the same technique to obtain analogous statements for
equivalences of real-analytic self-maps and vector fields under conjugations.
On the other hand, we provide an example of two sets of germs of smooth curves
that are equivalent of any finite order but not formally equivalent
Entwined Paths, Difference Equations and the Dirac Equation
Entwined space-time paths are bound pairs of trajectories which are traversed
in opposite directions with respect to macroscopic time. In this paper we show
that ensembles of entwined paths on a discrete space-time lattice are simply
described by coupled difference equations which are discrete versions of the
Dirac equation. There is no analytic continuation, explicit or forced, involved
in this description. The entwined paths are `self-quantizing'. We also show
that simple classical stochastic processes that generate the difference
equations as ensemble averages are stable numerically and converge at a rate
governed by the details of the stochastic process. This result establishes the
Dirac equation in one dimension as a phenomenological equation describing an
underlying classical stochastic process in the same sense that the Diffusion
and Telegraph equations are phenomenological descriptions of stochastic
processes.Comment: 15 pages, 5 figures Replacement 11/02 contains minor editorial
change
Mass of Colored Black Holes
New results pertaining to colored static black hole solutions to the
Einstein-Yang-Mills equations are obtained. The isolated horizons framework is
used to define the concept of Hamiltonian Horizon Mass of the black hole. An
unexpected relation between the ADM and Horizon masses of the black hole
solution with the ADM mass of the corresponding Bartnik-McKinnon soliton is
found. These results can be generalized to other non-linear theories and they
suggest a general testing bed for the instability of the corresponding hairy
black holes.Comment: 8 pages, no figures, Revtex file. Minor changes made to clarify some
formulas. References updated. Final version to appear in PRD/15
What Precision Electroweak Physics Says About the SU(6)/Sp(6) Little Higgs
We study precision electroweak constraints on the close cousin of the
Littlest Higgs, the SU(6)/Sp(6) model. We identify a near-oblique limit in
which the heavy W' and B' decouple from the light fermions, and then calculate
oblique corrections, including one-loop contributions from the extended top
sector and the two Higgs doublets. We find regions of parameter space that give
acceptably small precision electroweak corrections and only mild fine tuning in
the Higgs potential, and also find that the mass of the lightest Higgs boson is
relatively unconstrained by precision electroweak data. The fermions from the
extended top sector can be as light as 1 TeV, and the W' can be as light as 1.8
TeV. We include an independent breaking scale for the B', which can still have
a mass as low as a few hundred GeV.Comment: 52 pages, 16 figure
EP-1097: Comparison of outcomes and toxicities between IMRT and SIB-IMRT in cancers of hypopharynx
Utilization of print media for agriculture development: A case study of peasants
Shetkari is the print media that is focused to provide improved methods and techniques of cultivation to provide improved methods and techniques of cultivation to peasants in Western Maharashtra especially the literate, youth and commercial cultivator. Peasants are utilizing latest agricultural ideas for agricultural development. Agricultural development means economic growth along with maintaining their fertility of soil. To illustrate the role of print media, a study of Yalgund village of Kolhapur District is conducted. Case studies of big, medium marginal and large peasants are conducted to illustrate the importance of agricultural communication. It is found that big and small peasants have been applying the ideas to boots their agricultural economic into commercial profitable industry. The marginal farmer has implemented the technique of mixed cropping profitably. However, there is no utilization by the landless
Acoustic properties of colloidal crystals
We present a systematic study of the frequency band structure of acoustic
waves in crystals consisting of nonoverlapping solid spheres in a fluid. We
consider colloidal crystals consisting of polystyrene spheres in water, and an
opal consisting of close-packed silica spheres in air. The opal exhibits an
omnidirectional frequency gap of considerable width; the colloidal crystals do
not. The physical origin of the bands are discussed for each case in some
detail. We present also results on the transmittance of finite slabs of the
above crystals.Comment: 7 pages, 9 figures, prb approve
Identification and characterization of popular rice (Oryza sativa L.) varieties through chemical tests
Identification and characterization of crop varieties are crucial for ensuring the genetic purity of seeds. The present investigation was carried out to identify suitable chemical methods that are fast, reliable and easy for seed analysts, breeders and seed producers for identification of a variety. Twenty-five popular rice varieties in the seed supply chain of Tamil Nadu were subjected to phenol, modified phenol, NaOH, aroma, gelatinization temperature (alkali spreading value), GA3 and 2,4-D tests. The results of the experiment revealed that phenol and modified phenol tests changed the colour of TKM 9 and TRY 1 variety to brown but no colour change was observed in the variety I.W. Ponni variety. The NaOH test is useful for the identification of TKM 9 variety as it changed the colourless solution to red. GA3 and 2,4-D tests characterized the varieties based on the shoot growth into two and three groups respectively. However, all the variety lacked aroma and exhibited a high gelatinization temperature
Scattering of elastic waves by periodic arrays of spherical bodies
We develop a formalism for the calculation of the frequency band structure of
a phononic crystal consisting of non-overlapping elastic spheres, characterized
by Lam\'e coefficients which may be complex and frequency dependent, arranged
periodically in a host medium with different mass density and Lam\'e
coefficients. We view the crystal as a sequence of planes of spheres, parallel
to and having the two dimensional periodicity of a given crystallographic
plane, and obtain the complex band structure of the infinite crystal associated
with this plane. The method allows one to calculate, also, the transmission,
reflection, and absorption coefficients for an elastic wave (longitudinal or
transverse) incident, at any angle, on a slab of the crystal of finite
thickness. We demonstrate the efficiency of the method by applying it to a
specific example.Comment: 19 pages, 5 figures, Phys. Rev. B (in press
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