11,159 research outputs found
Quantum Gravity Equation In Schroedinger Form In Minisuperspace Description
We start from classical Hamiltonian constraint of general relativity to
obtain the Einstein-Hamiltonian-Jacobi equation. We obtain a time parameter
prescription demanding that geometry itself determines the time, not the matter
field, such that the time so defined being equivalent to the time that enters
into the Schroedinger equation. Without any reference to the Wheeler-DeWitt
equation and without invoking the expansion of exponent in WKB wavefunction in
powers of Planck mass, we obtain an equation for quantum gravity in
Schroedinger form containing time. We restrict ourselves to a minisuperspace
description. Unlike matter field equation our equation is equivalent to the
Wheeler-DeWitt equation in the sense that our solutions reproduce also the
wavefunction of the Wheeler-DeWitt equation provided one evaluates the
normalization constant according to the wormhole dominance proposal recently
proposed by us.Comment: 11 Pages, ReVTeX, no figur
Periodic Orbits in Polygonal Billiards
We review some properties of periodic orbit families in polygonal billiards
and discuss in particular a sum rule that they obey. In addition, we provide
algorithms to determine periodic orbit families and present numerical results
that shed new light on the proliferation law and its variation with the genus
of the invariant surface. Finally, we deal with correlations in the length
spectrum and find that long orbits display Poisson fluctuations.Comment: 30 pages (Latex) including 11 figure
Power loss in open cavity diodes and a modified Child Langmuir Law
Diodes used in most high power devices are inherently open. It is shown that
under such circumstances, there is a loss of electromagnetic radiation leading
to a lower critical current as compared to closed diodes. The power loss can be
incorporated in the standard Child-Langmuir framework by introducing an
effective potential. The modified Child-Langmuir law can be used to predict the
maximum power loss for a given plate separation and potential difference as
well as the maximum transmitted current for this power loss. The effectiveness
of the theory is tested numerically.Comment: revtex4, 11 figure
Opinion dynamics model with domain size dependent dynamics: novel features and new universality class
A model for opinion dynamics (Model I) has been recently introduced in which
the binary opinions of the individuals are determined according to the size of
their neighboring domains (population having the same opinion). The coarsening
dynamics of the equivalent Ising model shows power law behavior and has been
found to belong to a new universality class with the dynamic exponent and persistence exponent in one dimension. The
critical behavior has been found to be robust for a large variety of annealed
disorder that has been studied. Further, by mapping Model I to a system of
random walkers in one dimension with a tendency to walk towards their nearest
neighbour with probability , we find that for any ,
the Model I dynamical behaviour is prevalent at long times.Comment: 12 pages, 10 figures. To be published in "Journal of Physics :
Conference Series" (2011
Understanding of farmers' perception of climate change and adaptation strategies: A case study in Jhargram district of West Bengal, India
A study on farmers perceived prevalence of climate change, manifested by the phenomena like increasing temperature, fluctuating rainfall etc. and in the considered agro-ecological areas was conducted in Binpur II block of Jhargram district of West Bengal to assess the extent of farmers' perception about the climate change and their adaptation strategies to cope up with losses due to climate change. Results showed that the farmers' perception of climate change greatly influenced farmers' readiness to adapt climate change by considering some adjustments to their cultivation and production practices. The findings showed that the farmers' perception of climate change was at a high-level group of respondents. Results showed that 50% of respondents were optimistic with the idea that they can cope up the climate change problems if they get proper government assistance. Only about 13% of farmers perceived Government plans on climate change. Regarding the adaptation strategies, 40% of respondents followed more or less strategies, whereas most of the respondents did not adopt any strategies in this regard.
 
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