198,244 research outputs found
A Bi-Hamiltonian Formulation for Triangular Systems by Perturbations
A bi-Hamiltonian formulation is proposed for triangular systems resulted by
perturbations around solutions, from which infinitely many symmetries and
conserved functionals of triangular systems can be explicitly constructed,
provided that one operator of the Hamiltonian pair is invertible. Through our
formulation, four examples of triangular systems are exhibited, which also show
that bi-Hamiltonian systems in both lower dimensions and higher dimensions are
many and varied. Two of four examples give local 2+1 dimensional bi-Hamiltonian
systems and illustrate that multi-scale perturbations can lead to
higher-dimensional bi-Hamiltonian systems.Comment: 16 pages, to appear in J. Math. Phy
Reexamining the "finite-size" effects in isobaric yield ratios using a statistical abrasion-ablation model
The "finite-size" effects in the isobaric yield ratio (IYR), which are shown
in the standard grand-canonical and canonical statistical ensembles (SGC/CSE)
method, is claimed to prevent obtaining the actual values of physical
parameters. The conclusion of SGC/CSE maybe questionable for neutron-rich
nucleus induced reaction. To investigate whether the IYR has "finite-size"
effects, the IYR for the mirror nuclei [IYR(m)] are reexamined using a modified
statistical abrasion-ablation (SAA) model. It is found when the projectile is
not so neutron-rich, the IYR(m) depends on the isospin of projectile, but the
size dependence can not be excluded. In reactions induced by the very
neutron-rich projectiles, contrary results to those of the SGC/CSE models are
obtained, i.e., the dependence of the IYR(m) on the size and the isospin of the
projectile is weakened and disappears both in the SAA and the experimental
results.Comment: 5 pages and 4 figure
Pressure effects in polycyclic aromatic nitrogenated heterocycles (PANHs): Diagnostic qualities and cosmobarometry potential
Lepton Family Symmetry and Neutrino Mass Matrix
The standard model of leptons is extended to accommodate a discrete Z_3 X Z_2
family symmetry. After rotating the charged-lepton mass matrix to its diagonal
form, the neutrino mass matrix reveals itself as very suitable for explaining
atmospheric and solar neutrino oscillation data. A generic requirement of this
approach is the appearance of three Higgs doublets at the electroweak scale,
with observable flavor violating decays.Comment: 9 pages, including 1 figur
Measuring an entropy in heavy ion collisions
We propose to use the coincidence method of Ma to measure an entropy of the
system created in heavy ion collisions. Moreover we estimate, in a simple
model, the values of parameters for which the thermodynamical behaviour sets
in.Comment: LATTICE98(hightemp), 3 pages, LaTeX with two eps figure
Supersymmetric A_4 X Z_3 and A_4 Realizations of Neutrino Tribimaximal Mixing Without and With Corrections
In an improved application of the tetrahedral symmetry A_4 first introduced
by Ma and Rajasekaran, supplemented by the discrete symmetry Z_3 as well as
supersymmetry, a two-parameter form of the neutrino mass matrix is derived
which exhibits the tribimaximal mixing of Harrison, Perkins, and Scott. This
form is the same one obtained previously by Altarelli and Feruglio, and the
inverse of that obtained by Babu and He. If only A_4 is used, then corrections
appear, making tan^2(theta_{12}) differenet from 0.5, without changing
significantly sin^2(2 theta_{23}) from one or theta_{13} from zero.Comment: 8 pages, no figur
A refined invariant subspace method and applications to evolution equations
The invariant subspace method is refined to present more unity and more
diversity of exact solutions to evolution equations. The key idea is to take
subspaces of solutions to linear ordinary differential equations as invariant
subspaces that evolution equations admit. A two-component nonlinear system of
dissipative equations was analyzed to shed light on the resulting theory, and
two concrete examples are given to find invariant subspaces associated with
2nd-order and 3rd-order linear ordinary differential equations and their
corresponding exact solutions with generalized separated variables.Comment: 16 page
A Class of Coupled KdV systems and Their Bi-Hamiltonian Formulations
A Hamiltonian pair with arbitrary constants is proposed and thus a sort of
hereditary operators is resulted. All the corresponding systems of evolution
equations possess local bi-Hamiltonian formulation and a special choice of the
systems leads to the KdV hierarchy. Illustrative examples are given.Comment: 8 pages, late
Algebraic Structure of Discrete Zero Curvature Equations and Master Symmetries of Discrete Evolution Equations
An algebraic structure related to discrete zero curvature equations is
established. It is used to give an approach for generating master symmetries of
first degree for systems of discrete evolution equations and an answer to why
there exist such master symmetries. The key of the theory is to generate
nonisospectral flows from the discrete spectral
problem associated with a given system of discrete evolution equations. Three
examples are given.Comment: 24 pages, LaTex, revise
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