7,244 research outputs found
Generalized Solutions for Quantum Mechanical Oscillator on K\"{a}hler Conifold
We study the possible generalized boundary conditions and the corresponding
solutions for the quantum mechanical oscillator model on K\"{a}hler conifold.
We perform it by self-adjoint extension of the the initial domain of the
effective radial Hamiltonian. Remarkable effect of this generalized boundary
condition is that at certain boundary condition the orbital angular momentum
degeneracy is restored! We also recover the known spectrum in our formulation,
which of course correspond to some other boundary condition.Comment: 7 pages, latex, no figur
The Fractional Quantum Hall effect in an array of quantum wires
We demonstrate the emergence of the quantum Hall (QH) hierarchy in a 2D model
of coupled quantum wires in a perpendicular magnetic field. At commensurate
values of the magnetic field, the system can develop instabilities to
appropriate inter-wire electron hopping processes that drive the system into a
variety of QH states. Some of the QH states are not included in the
Haldane-Halperin hierarchy. In addition, we find operators allowed at any field
that lead to novel crystals of Laughlin quasiparticles. We demonstrate that any
QH state is the groundstate of a Hamiltonian that we explicitly construct.Comment: Revtex, 4 pages, 2 figure
Translational diffusion of fluorescent probes on a sphere: monte carlo simulations, theory, and fluorescence anisotropy experiment
Translational diffusion of fluorescent molecules on curved surfaces (micelles, vesicles, and proteins) depolarizes the fluorescence. A Monte Carlo simulation method was developed to obtain the fluorescence anisotropy decays for the general case of molecular dipoles tilted at an angle a to the surface normal. The method is used to obtain fluorescence anisotropy decay due to diffusion of tilted dipoles on a spherical surface, which matched well with the exact solution for the sphere. The anisotropy decay is a single exponential for α = 0° , a double exponential for α = 90° , and three exponentials for intermediate angles. The slower decay component(s) for α ≠ 0 arise due to the geometric phase factor. Although the anisotropy decay equation contains three exponentials, there are only two parameters, namely a and the rate constant, Dtr/R2, where Dtr is the translational diffusion coefficient and R is the radius of the sphere. It is therefore possible to determine the orientation angle and translational diffusion coefficient from the experimental fluorescence anisotropy data. This method was applied in interpreting the fluorescence anisotropy decay of Nile red in SDS micelles. It is necessary, however, to include two other independent mechanisms of fluorescence depolarization for molecules intercalated in micelles. These are the wobbling dynamics of the molecule about the molecular long axis, and the rotation of the spherical micelle as a whole. The fitting of the fluorescence anisotropy decay to the full equation gave the tilt angle of the molecular dipoles to be 1± 2° and the translational diffusion coefficient to be 1.3± 0.1×10-10 m2/s
Dipole binding in a cosmic string background due to quantum anomalies
We propose quantum dynamics for the dipole moving in cosmic string background
and show that the classical scale symmetry of a particle moving in cosmic
string background is still restored even in the presence of dipole moment of
the particle. However, we show that the classical scale symmetry is broken due
to inequivalent quantization of the the non-relativistic system. The
consequence of this quantum anomaly is the formation of bound state in the
interval \xi\in(-1,1). The inequivalent quantization is characterized by a
1-parameter family of self-adjoint extension parameter \Sigma. We show that
within the interval \xi\in(-1,1), cosmic string with zero radius can bind the
dipole and the dipole does not fall into the singularity.Comment: Accepted for publication in Phys. Rev.
Self-Adjointness of Generalized MIC-Kepler System
We have studied the self-adjointness of generalized MIC-Kepler Hamiltonian,
obtained from the formally self-adjoint generalized MIC-Kepler Hamiltonian. We
have shown that for \tilde l=0, the system admits a 1-parameter family of
self-adjoint extensions and for \tilde l \neq 0 but \tilde l <{1/2}, it has
also a 1-parameter family of self-adjoint extensions.Comment: 11 pages, Latex, no figur
Quantization of exciton in magnetic field background
The possible mismatch between the theoretical and experimental absorption of
the edge peaks in semiconductors in a magnetic field background may arise due
to the approximation scheme used to analytically calculate the absorption
coefficient. As a possible remedy we suggest to consider nontrivial boundary
conditions on x-y plane by in-equivalently quantizing the exciton in background
magnetic field. This inequivalent quantization is based on von Neumann's method
of self-adjoint extension, which is characterized by a parameter \Sigma. We
obtain bound state solution and scattering state solution, which in general
depend upon the self-adjoint extension parameter \Sigma. The parameter \Sigma
can be used to fine tune the optical absorption coefficient K(\Sigma) to match
with the experiment.Comment: 5 pages, 1 figur
Quantum oscillator on complex projective space (Lobachewski space) in constant magnetic field and the issue of generic boundary conditions
We perform a 1-parameter family of self-adjoint extensions characterized by
the parameter . This allows us to get generic boundary conditions for
the quantum oscillator on dimensional complex projective
space() and on its non-compact version i.e., Lobachewski
space() in presence of constant magnetic field. As a result, we
get a family of energy spectrums for the oscillator. In our formulation the
already known result of this oscillator is also belong to the family. We have
also obtained energy spectrum which preserve all the symmetry (full hidden
symmetry and rotational symmetry) of the oscillator. The method of self-adjoint
extensions have been discussed for conic oscillator in presence of constant
magnetic field also.Comment: Accepted in Journal of Physics
Perspectives on mariculture in India
The aquaculture sector in India has a long history and has
witnessed an increase in production for the last two decades
with an annual growth rate of 6-7%. This means that India is
the second largest producer of farmed fish in the world after
China. At present, freshwater aquaculture contributes to a major
proportion of the aquaculture production from India (FAO, 2014).
In India, brackish water aquaculture is a traditional practise in
natural coastal low land areas such as pokkali fields (salt resistant
deepwater paddy fields along the Kerala coast), bheries (man
made impoundments in coastal wetlands of West Bengal state),
khar lands (tidal lands in Karnataka state) and khazan lands (saline
flood plains along tidal estuaries in Goa) with varying production
capacities and depending on tidal influences and natural supply
of seeds (Kutty, 1999). After several trials, under different R&D
programs, scientific coastal farming was initiated in the early
1990s with the active involvement of different stakeholders. Since
then, shrimp farming has grown tremendously and at present,
dominates coastal aquaculture. However, the frequent problems
in shrimp culture raises the question on the sustainability of
coastal aquaculture as it is solely dependent on a single group i.e.
shrimp. Therefore, species diversification with high value marine
finfish is now being considered to develop a sustainable and ecofriendly
coastal aquaculture industry in India
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