3,862 research outputs found
Quantizations on the circle and coherent states
We present a possible construction of coherent states on the unit circle as
configuration space. Our approach is based on Borel quantizations on S^1
including the Aharonov-Bohm type quantum description. The coherent states are
constructed by Perelomov's method as group related coherent states generated by
Weyl operators on the quantum phase space Z x S^1. Because of the duality of
canonical coordinates and momenta, i.e. the angular variable and the integers,
this formulation can also be interpreted as coherent states over an infinite
periodic chain. For the construction we use the analogy with our quantization
and coherent states over a finite periodic chain where the quantum phase space
was Z_M x Z_M. The coherent states constructed in this work are shown to
satisfy the resolution of unity. To compare them with canonical coherent
states, also some of their further properties are studied demonstrating
similarities as well as substantial differences.Comment: 15 pages, 4 figures, accepted in J. Phys. A: Math. Theor. 45 (2012)
for the Special issue on coherent states: mathematical and physical aspect
Risk Factors for Hospital Malpractice Exposure: Implications for Managers and Insurers
The possibility of identifying certain variables that might serve as predictors of above- or below-average medical malpractice claims experience was explored. Results showed that it is possible to identify significant risk factors
Coherent states on the circle
We present a possible construction of coherent states on the unit circle as
configuration space. In our approach the phase space is the product Z x S^1.
Because of the duality of canonical coordinates and momenta, i.e. the angular
variable and the integers, this formulation can also be interpreted as coherent
states over an infinite periodic chain. For the construction we use the analogy
with our quantization over a finite periodic chain where the phase space was
Z_M x Z_M. Properties of the coherent states constructed in this way are
studied and the coherent states are shown to satisfy the resolution of unity.Comment: 7 pages, presented at GROUP28 - "28th International Colloquium on
Group Theoretical Methods in Physics", Newcastle upon Tyne, July 2010.
Accepted in Journal of Physics Conference Serie
Natural mortality of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) eggs in Argentina and Italy, and first record of Encarsia porteri (Mercet) (Hymenoptera: Aphelinidae) affecting its populations
En este estudio se evaluaron los agentes oĂłfagos de T. absoluta de presencia
espontánea en cultivos de tomate en SudamĂ©rica (NOA y CinturĂłn HortĂcola Platense, Argentina) y en Europa (Lazio, Italia). Se reporta el listado de especies encontradas y las tasas de mortalidad natural por parasitismo y depredaciĂłn en cultivos de ambos continentes. Además, se informa el primer registro de Encarsia porteri (Mercet) (Hymenoptera: Aphelinidae) parasitando huevos de la polilla.Oophagous biological control agents of T. absoluta naturally present in crops in South
America (Buenos Aires and Tucumán Provinces, Argentina) and Europe (Lazio, Italia)
were surveyed. A taxonomic list of species and the natural mortality rates caused by
parasitism and predation are reported. Furthermore, the first record of Encarsia porteri
(Mercet) (Hymenoptera: Aphelinidae) parasitizing T. absoluta eggs is informed.Fil: Luft, Érica.
San Miguel de Tucumán (Tucumán, Argentina). CONICET - Planta Piloto de Procesos Industriales MicrobiolĂłgicos-BiotecnologĂa, Div. Control BiolĂłgico.Fil: Luna, MarĂa Gabriela.
Universidad Nacional de La PlataFil: Galise, Gabriele.
Italia. UniversitĂ degli Studi della Tuscia.Fil: Speranza, Stefano.
Italia. UniversitĂ degli Studi della Tuscia.Fil: Virla, Eduardo G..
San Miguel de Tucumán (Tucumán, Argentina). CONICET - Planta Piloto de Procesos Industriales MicrobiolĂłgicos-BiotecnologĂa, Div. Control BiolĂłgico
Dihedral symmetry of periodic chain: quantization and coherent states
Our previous work on quantum kinematics and coherent states over finite
configuration spaces is extended: the configuration space is, as before, the
cyclic group Z_n of arbitrary order n=2,3,..., but a larger group - the
non-Abelian dihedral group D_n - is taken as its symmetry group. The
corresponding group related coherent states are constructed and their
overcompleteness proved. Our approach based on geometric symmetry can be used
as a kinematic framework for matrix methods in quantum chemistry of ring
molecules.Comment: 13 pages; minor changes of the tex
Subthreshold laser therapy with a standardized macular treatment pattern in chronic central serous chorioretinopathy
PURPOSE There is an ongoing controversial debate about the effectiveness of laser treatments in chronic central serous chorioretinopathy (cCSC). We performed a prospective non-randomized interventional study to learn about the effects of a subthreshold laser treatment (Topcon Endpoint Management™, Topcon Healthcare Inc., Tokyo, Japan) in patients with cCSC. METHODS Patients with cCSC and a minimum symptom duration of 4~months were included and treated with a standardized laser pattern covering the macular area. Retreatment was performed every 3~months if persistent subretinal fluid was observed. The primary endpoint was resolution of subretinal fluid at 6~months. Further outcome parameters included best corrected visual acuity, microperimetry, central macular and subfoveal choroidal thickness. RESULTS A total of 42 eyes of 39 patients were included. Mean patient age was 48 ± 10.6~years (range 25-67). Mean symptomatic time before inclusion into the study was 134 ± 133.4~weeks (16-518). Before inclusion, 78.6% of the patients had failed to resolve subretinal fluid under mineralocorticoid receptor antagonists and 14.3% had a recurrence after half-dose photodynamic therapy. Complete resolution of subretinal fluid was observed in 42.9% at 6~months and in 53.8% at 12~months after baseline. Central retinal thickness decreased from 398 ± 135~µm to 291 ± 68~µm (p < 0.001), subfoveal choroidal thickness changed slightly (430 ± 116~µm to 419 ± 113~µm, p = 0.026), microperimetry-derived macular function improved by 19.1 ± 4.7~dB to 21.3 ± 4.8~dB (p = 0.008) and mean BCVA improved by 4.9 ± 8.6 ETDRS letters (p < 0.001). CONCLUSION The results show that the investigated laser treatment is effective in reducing subretinal fluid and leads to an improvement of functional parameters
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