706 research outputs found
Uniqueness and Nondegeneracy of Ground States for in
We prove uniqueness of ground state solutions for the
nonlinear equation in , where
and for and for . Here denotes the fractional Laplacian
in one dimension. In particular, we generalize (by completely different
techniques) the specific uniqueness result obtained by Amick and Toland for
and in [Acta Math., \textbf{167} (1991), 107--126]. As a
technical key result in this paper, we show that the associated linearized
operator is nondegenerate;
i.\,e., its kernel satisfies .
This result about proves a spectral assumption, which plays a central
role for the stability of solitary waves and blowup analysis for nonlinear
dispersive PDEs with fractional Laplacians, such as the generalized
Benjamin-Ono (BO) and Benjamin-Bona-Mahony (BBM) water wave equations.Comment: 45 page
Independence of , Poincare Invariance and the Non-Conservation of Helicity
A relativistic constituent quark model is found to reproduce the recent data
regarding the ratio of proton form factors, . We show that
imposing Poincare invariance leads to substantial violation of the helicity
conservation rule, as well as an analytic result that the ratio
for intermediate values of .Comment: 13 pages, 7 figures, to be submitted to Phys. Rev. C typos corrected,
references added, 1 new figure to show very high Q^2 behavio
Delta M_K and epsilon_K in the left-right supersymmetric model
We perform a complete analysis of processes in the kaon system
and evaluate and in the left-right supersymmetric
model. We include analytic expressions for the contributions of gluinos,
neutralinos and charginos. We obtain general constraints on off-diagonal mass
terms between the first two generations of both down-type and up-type squarks.
In the down-squark sector, we compare the results with gluino-only estimates.
In the up-squark sector, we find a complete set of bounds on all combinations
of chirality conserving or chirality flipping parameters. Finally, we comment
on the size of the bounds obtained by imposing left-right symmetry in the
squark sector.Comment: 22 pages, 1 figure and 4 table
New low-stress PECVD poly-SiGe layers for MEMS
Thick poly-SiGe layers, deposited by plasma-enhanced chemical vapor deposition (PECVD), are very promising structural layers for use in microaccelerometers, microgyroscopes or for thin-film encapsulation, especially for applications where the thermal budget is limited. In this work it is shown for the first time that these layers are an attractive alternative to low-pressure CVD (LPCVD) poly-Si or poly-SiGe because of their high growth rate (100-200 nm/min) and low deposition temperature (520/spl deg/C-590/spl deg/C). The combination of both of these features is impossible to achieve with either LPCVD SiGe (2-30 nm/min growth rate) or LPCVD poly-Si (annealing temperature higher than 900/spl deg/C to achieve structural layer having low tensile stress). Additional advantages are that no nucleation layer is needed (deposition directly on SiO/sub 2/ is possible) and that the as-deposited layers are polycrystalline. No stress or dopant activation anneal of the structural layer is needed since in situ phosphorus doping gives an as-deposited tensile stress down to 20 MPa, and a resistivity of 10 m/spl Omega/-cm to 30 m/spl Omega/-cm. With in situ boron doping, resistivities down to 0.6 m/spl Omega/-cm are possible. The use of these films as an encapsulation layer above an accelerometer is shown
FAPRI 2004 U.S. and World Agricultural Outlook
Crop Production/Industries, Livestock Production/Industries,
FAPRI 2006 U.S. and World Agricultural Outlook
The FAPRI 2006 U.S. and World Agricultural Outlook presents projections of world agricultural production, consumption, and trade under average weather patterns, existing farm policy, and policy commitments under current trade agreements and custom unions. Despite continued high energy prices, world economic growth is expected to remain strong in the coming decade, above 3% per annum. Other major drivers of the 2006 baseline include new bio-energy policies in several large countries, EU sugar policy reform, sanitary and phytosanitary (SPS) shocks in livestock and poultry markets, and movements in the exchange rate.Crop Production/Industries, International Relations/Trade, Livestock Production/Industries,
Nonlinear Realization of Chiral Symmetry on the Lattice
We formulate lattice theories in which chiral symmetry is realized
nonlinearly on the fermion fields. In this framework the fermion mass term does
not break chiral symmetry. This property allows us to use the Wilson term to
remove the doubler fermions while maintaining exact chiral symmetry on the
lattice. Our lattice formulation enables us to address non-perturbative
questions in effective field theories of baryons interacting with pions and in
models involving constituent quarks interacting with pions and gluons. We show
that a system containing a non-zero density of static baryons interacting with
pions can be studied on the lattice without encountering complex action
problems. In our formulation one can also decide non-perturbatively if the
chiral quark model of Georgi and Manohar provides an appropriate low-energy
description of QCD. If so, one could understand why the non-relativistic quark
model works.Comment: 34 pages, 2 figures, revised version to be published in J. High
Energy Phys. (changes in the 1st paragraph, additional descriptions on the
nature of the coordinate singularities in Sec.2, references added
FAPRI 2005 U.S. and World Agricultural Outlook
Crop Production/Industries, Livestock Production/Industries,
A calculation of the QCD phase diagram at finite temperature, and baryon and isospin chemical potentials
We study the phases of a two-flavor Nambu-Jona-Lasinio model at finite
temperature , baryon and isospin chemical potentials:
, . This study
completes a previous analysis where only small isospin chemical potentials
were consideredComment: 21 pages, 13 figures included, two more refernces adde
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