43,490 research outputs found
Is there a prescribed parameter's space for the adiabatic geometric phase?
The Aharonov-Anandan and Berry phases are determined for the cyclic motions
of a non-relativistic charged spinless particle evolving in the superposition
of the fields produced by a Penning trap and a rotating magnetic field.
Discussion about the selection of the parameter's space and the relationship
between the Berry phase and the symmetry of the binding potential is given.Comment: 7 pages, 2 figure
Wronskian formula for confluent second-order supersymmetric quantum mechanics
The confluent second-order supersymmetric quantum mechanics, for which the
factorization energies tend to a single value, is studied. We show that the
Wronskian formula remains valid if generalized eigenfunctions are taken as seed
solutions. The confluent algorithm is used to generate SUSY partners of the
Coulomb potential.Comment: 7 pages, 1 figure, to be published in Physics Letters
Is the bulbus arteriosus of fish homologous to the mamalian intrapericardial thoracic arteries?
El resumen aparece en el Program & Abstracts of the 10th International Congress of Vertebrate Morphology, Barcelona 2013.Anatomical Record, Volume 296, Special Feature — 1: P-089.Two major findings have significantly improved our understanding of the
embryology and evolution of the arterial pole of the vertebrate heart (APVH): 1) a
new embryonic presumptive cardiac tissue, named second heart field (SHF), forms
the myocardium of the outflow tract, and the walls of the ascending aorta (AA) and
the pulmonary trunk (PT) in mammals and birds; 2) the bulbus arteriosus (BA),
previously thought to be an actinopterygian apomorphy, is present in all basal
Vertebrates, and probably derives from the SHF. We hypothesized that the
intrapericardial portions of the AA and the PT of mammals are homologous to the
BA of basal vertebrates. To test this, we performed 1) a literature review of the
anatomy and embryology of the APVH; 2) novel anatomical, histomorphological,
and embryological analyses of the APVH, comparing basal (Galeus atlanticus), with
apical (Mus musculus and Mesocricetus auratus) vertrebrates. Evidence obtained:
1) Anatomically, BA, AA, and PT are muscular tubes into the pericardial cavity,
which connect the distal myocardial outflow tracts with the aortic arch system.
Coronary arteries run through or originate at these anatomical structures; 2)
Histologically, BA, AA, and PT show an inner layer of endothelium covered by
circumferentially oriented smooth muscle cells, collagen fibers, and lamellar
elastin. The histomorphological differences between the BA and the ventral aorta
parallel those between intrapericardial and extrapericardial great arteries; 3)
Embryologically, BA, AA, and PT are composed of smooth muscle cells derived
from the SHF. They show a similar mechanism of development: incorporation of
SHF‐derived cells into the pericardial cavity, and distal‐to‐proximal differentiation
into an elastogenic cell linage.
In conclusion, anatomical, histological and embryological evidence supports the
hypothesis that SHF is a developmental unit responsible for the formation of the
APVH. The BA and the intrapericardial portions of the great arteries must be
considered homologous structures.Proyecto P10-CTS-6068 (Junta de Andalucía); proyecto CGL-16417 (Ministerio de Ciencia e Innovación); Fondos FEDER
Harmonic Oscillator SUSY Partners and Evolution Loops
Supersymmetric quantum mechanics is a powerful tool for generating exactly
solvable potentials departing from a given initial one. If applied to the
harmonic oscillator, a family of Hamiltonians ruled by polynomial Heisenberg
algebras is obtained. In this paper it will be shown that the SUSY partner
Hamiltonians of the harmonic oscillator can produce evolution loops. The
corresponding geometric phases will be as well studied
Trends in Supersymmetric Quantum Mechanics
Along the years, supersymmetric quantum mechanics (SUSY QM) has been used for studying solvable quantum potentials. It is the simplest method to build Hamiltonians with prescribed spectra in the spectral design. The key is to pair two Hamiltonians through a finite order differential operator. Some related subjects can be simply analyzed, as the algebras ruling both Hamiltonians and the associated coherent states. The technique has been applied also to periodic potentials, where the spectra consist of allowed and forbidden energy bands. In addition, a link with non-linear second-order differential equations, and the possibility of generating some solutions, can be explored. Recent applications concern the study of Dirac electrons in graphene placed either in electric or magnetic fields, and the analysis of optical systems whose relevant equations are the same as those of SUSY QM. These issues will be reviewed briefly in this paper, trying to identify the most important subjects explored currently in the literature
Second order SUSY transformations with `complex energies'
Second order supersymmetry transformations which involve a pair of complex
conjugate factorization energies and lead to real non-singular potentials are
analyzed. The generation of complex potentials with real spectra is also
studied. The theory is applied to the free particle, one-soliton well and
one-dimensional harmonic oscillator.Comment: 11 pages, 2 figures, submitted on 23 August 2002 to Phys. Lett.
New supersymmetric partners for the associated Lame potentials
We obtain exact solutions of the one-dimensional Schrodinger equation for
some families of associated Lame potentials with arbitrary energy through a
suitable ansatz, which may be appropriately extended for other such a families.
The formalism of supersymmetric quantum mechanics is used to generate new
exactly solvable potentials.Comment: 8 pages, 2 figures, submitted on 24 November 2004 to Phys. Lett.
Reference priors in non-normal location problems
Bayesian Statistics;Statistical Distribution
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