79,919 research outputs found
Comment on "Wave functions for a Duffin-Kemmer-Petiau particle in a time-dependent potential"
It is shown that the paper "Wave functions for a Duffin-Kemmer-Petiau
particle in a time-dependent potential", by Merad and Bensaid [J. Math. Phys.
48, 073515 (2007)] is not correct in using inadvertently a non-Hermitian
Hamiltonian in a formalism that does require Hermitian Hamiltonians.Comment: 2 page
Corroborating the equivalence between the Duffin-Kemmer-Petiau and the Klein-Gordon and Proca equations
It is shown that the Hamiltonian version of the Duffin-Kemmer-Petiau theory
with electromagnetic coupling brings about a source term at the current. It is
also shown that such a source term disappears from the scenario if one uses the
correct physical form for the Duffin-Kemmer-Petiau field, regardless the choice
for representing the Duffin-Kemmer-Petiau matrices. This result is used to fix
the ambiguity in the electromagnetic coupling in the Duffin-Kemmer-Petiau
theory. Moreover, some widespread misconceptions about the Hermiticity in the
Duffin-Kemmer-Petiau theory are discussed.Comment: 13 pages, to appears in Phys. Rev.
On the bound-state spectrum of a nonrelativistic particle in the background of a short-ranged linear potential
The nonrelativistic problem of a particle immersed in a triangular potential
well, set forth by N.A. Rao and B.A. Kagali, is revised. It is shown that these
researchers misunderstood the full meaning of the potential and obtained a
wrong quantization condition. By exploring the space inversion symmetry, this
work presents the correct solution to this problem with potential applications
in electronics in a simple and transparent way
Missing solution in a Cornell potential
Missing bound-state solutions for fermions in the background of a Cornell
potential consisting of a mixed scalar-vector-pseudoscalar coupling is
examined. Charge-conjugation operation, degeneracy and localization are
discussed
Trisecting Smooth 4-dimensional Cobordisms
We extend the theory of relative trisections of smooth, compact, oriented
-manifolds with connected boundary given by Gay and Kirby to include
-manifolds with an arbitrary number of boundary components. Additionally, we
provide sufficient conditions under which relatively trisected -manifolds
can be glued to one another along diffeomorphic boundary components so as to
induce a trisected manifold. These two results allow us to define a category
whose objects are smooth, closed, oriented -manifolds
equipped with open book decompositions, and morphisms are relatively trisected
cobordisms. Additionally, we extend the Hopf stabilization of open book
decompositions to a relative stabilization of relative trisections.Comment: 19 pages, 11 Figure
A second order cone formulation of continuous CTA model
The final publication is available at link.springer.comIn this paper we consider a minimum distance Controlled Tabular Adjustment (CTA) model for statistical disclosure limitation (control) of tabular data. The goal of the CTA model is to find the closest safe table to some original tabular data set that contains sensitive information. The measure of closeness is usually measured using l1 or l2 norm; with each measure having its advantages and disadvantages. Recently, in [4] a regularization of the l1 -CTA using Pseudo-Huber func- tion was introduced in an attempt to combine positive characteristics of both l1 -CTA and l2 -CTA. All three models can be solved using appro- priate versions of Interior-Point Methods (IPM). It is known that IPM in general works better on well structured problems such as conic op- timization problems, thus, reformulation of these CTA models as conic optimization problem may be advantageous. We present reformulation of Pseudo-Huber-CTA, and l1 -CTA as Second-Order Cone (SOC) op- timization problems and test the validity of the approach on the small example of two-dimensional tabular data set.Peer ReviewedPostprint (author's final draft
Border X-ing
The sun out-stretched its bright arms in an embrace with the mesquite trees that beckoned upwards. The wind greeted the clothes drying upon delicate wire while my mother meticulously placed white towels in the light and the jeans under the shade of the Arizona Ash. The washboard sits upright in the bucket full of suds and other assorted laundry. Inside the shed there is both a working dryer and washer only a few years old, but she has chosen to do this chore outside. Here she can close her eyes and be back in Mexico with the dry heat and the dusty wind hitting against the houses of colorful concrete walls. She senses the animals of the ranch pecking at the maize that has been long picked since the harvest. She hears the commotion of the bar-b-que that is smoking next door at Tia Alaida’s house, a world that I have only visited a few times, never quite experiencing it as deeply as she. [excerpt
A new species of Prosekia (Philosciidae, Isopoda) from an inundation forest (igapó) in the Central Amazon
Prosekia tarumae n. sp. (Philosciidae, Isopoda) from a Central Amazonian black-water inundation forest (lgapó) is described
Relativistic Effects of Mixed Vector-Scalar-Pseudoscalar Potentials for Fermions in 1+1 Dimensions
The problem of fermions in the presence of a pseudoscalar plus a mixing of
vector and scalar potentials which have equal or opposite signs is
investigated. We explore all the possible signs of the potentials and discuss
their bound-state solutions for fermions and antifermions. The cases of mixed
vector and scalar P\"{o}schl-Teller-like and pseudoscalar kink-like potentials,
already analyzed in previous works, are obtained as particular cases
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