3,748 research outputs found
Iterative Solutions for Low Lying Excited States of a Class of Schroedinger Equation
The convergent iterative procedure for solving the groundstate Schroedinger
equation is extended to derive the excitation energy and the wave function of
the low-lying excited states. The method is applied to the one-dimensional
quartic potential problem. The results show that the iterative solution
converges rapidly when the coupling is not too small.Comment: 14 pages, 4 figure
Deviations of the Lepton Mapping Matrix from the Harrison-Perkins-Scott Form
We propose a simple set of hypotheses governing the deviations of the
leptonic mapping matrix from the Harrison-Perkins-Scott (HPS) form. These
deviations are supposed to arise entirely from a perturbation of the mass
matrix in the charged lepton sector. The perturbing matrix is assumed to be
purely imaginary (thus maximally -violating) and to have a strength in
energy scale no greater (but perhaps smaller) than the muon mass. As we shall
show, it then follows that the absolute value of the mapping matrix elements
pertaining to the tau lepton deviate by no more than from their HPS values.
Assuming that can be neglected, we derive two simple
constraints on the four parameters , , ,
and of the mapping matrix. These constraints are independent of the
details of the imaginary -violating perturbation of the charged lepton mass
matrix. We also show that the and parts of the mapping matrix have a
definite form governed by two parameters and ; any deviation of
order can be accommodated by adjusting these two parameters.Comment: 31 pages, 2 figure
Jarlskog Invariant of the Neutrino Mapping Matrix
The Jarlskog Invariant of the neutrino mapping matrix is
calculated based on a phenomenological model which relates the smallness of
light lepton masses and (of ) with the smallness of
violation. For small violating phase in the lepton sector,
is proportional to , but and are proportional
to . This leads to . Assuming
, we find
, consistent with the present experimental
data.Comment: 19 page
Noncompact Lattice Formulation of Gauge Theories
We expand the gauge field in terms of a suitably constructed complete set of
Bloch wave functions, each labeled by a band designation and a wave
number restricted to the Brillouin zone. A noncompact formulation
of lattice QCD (or QED) can be derived by restricting the expansion only to the
-band () functions, which are simple continuum
interpolations of discrete values associated with sites or links on a lattice.
The exact continuum theory can be reached through the inclusion of all and bands, without requiring the lattice size . This makes it possible, at a nonzero , for the lattice coupling
to act as the renormalized continuum coupling. All physical
results in the continuum are, of course, independent of .Comment: 72 pages, 3 Postscript figure
A large scale prediction of bacteriocin gene blocks suggests a wide functional spectrum for bacteriocins
Bacteriocins are peptide-derived molecules produced by bacteria, whose
recently-discovered functions include virulence factors and signalling
molecules as well as their better known roles as antibiotics. To date, close to
five hundred bacteriocins have been identified and classified. Recent
discoveries have shown that bacteriocins are highly diverse and widely
distributed among bacterial species. Given the heterogeneity of bacteriocin
compounds, many tools struggle with identifying novel bacteriocins due to their
vast sequence and structural diversity. Many bacteriocins undergo
post-translational processing or modifications necessary for the biosynthesis
of the final mature form. Enzymatic modification of bacteriocins as well as
their export is achieved by proteins whose genes are often located in a
discrete gene cluster proximal to the bacteriocin precursor gene, referred to
as \textit{context genes} in this study. Although bacteriocins themselves are
structurally diverse, context genes have been shown to be largely conserved
across unrelated species. Using this knowledge, we set out to identify new
candidates for context genes which may clarify how bacteriocins are
synthesized, and identify new candidates for bacteriocins that bear no sequence
similarity to known toxins. To achieve these goals, we have developed a
software tool, Bacteriocin Operon and gene block Associator (BOA) that can
identify homologous bacteriocin associated gene clusters and predict novel
ones. We discover that several phyla have a strong preference for bactericon
genes, suggesting distinct functions for this group of molecules. Availability:
https://github.com/idoerg/BOAComment: Accepted for publication in BMC Bioinformatic
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