842 research outputs found
Gravitational Phase Operator and Cosmic Strings
A quantum equivalence principle is formulated by means of a gravitational
phase operator which is an element of the Poincare group. This is applied to
the spinning cosmic string which suggests that it may (but not necessarily)
contain gravitational torsion. A new exact solution of the Einstein-
Cartan-Sciama-Kibble equations for the gravitational field with torsion is
obtained everywhere for a cosmic string with uniform energy density, spin
density and flux. A novel effect due to the quantized gravitational field of
the cosmic string on the wave function of a particle outside the string is used
to argue that spacetime points are not meaningful in quantum gravity.Comment: 22 pages, to be published Phys. Rev. D. Some minor changes have been
made and a reference has been added to the paper of D.V. Gal'tsov and P.S.
Letelier, Phys. Rev. D 47 (1993) 4273, which first contained the metric (2.2)
external to the cosmic string. The present paper extends this solution to a
regular solution inside the string as wel
Classical and Quantum Interaction of the Dipole
A unified and fully relativistic treatment of the interaction of the electric
and magnetic dipole moments of a particle with the electromagnetic field is
given. New forces on the particle due to the combined effect of electric and
magnetic dipoles are obtained. Four new experiments are proposed, three of
which would observe topological phase shifts.Comment: 10 pages, Latex/Revtex. Some minor errors have been correcte
The non-Abelian state-dependent gauge field in optics
The covariant formulation of the quantum dynamics in CP(1) should lead to the
observable geometrodynamical effects for the local dynamical variable of the
light polarization states.Comment: 8 pages, 3 figures, LaTe
Bottom Trawling - A Potential threat to the Ecology and benthic communities of Gulf of Mannar
It is now widely appreciated that an important aspect of protecting fish stocks is the conservation of the habitats and animal communities on which those stocks depend. Over the years, fish catching techniques and devices have undergone remarkable variations, every time improving their efficiency. Trawl net exploits fish and other organisms from the bottom of the seas
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Conncetionist Variable-Binding By Optimization
Symbolic AI systems based on logical or frame languages can easily perform inferencesthat are still beyond the capability of most connectionist networks. This paper presents a strategy for implementing in connectionist networks the basic mechanisms of variable binding, dynamic frzune allocation and equality that underlie many of the types of inferences commonly handled by frame systems, including inheritance, subsumption and abductive inference. The paper describes a scheme for translating frame definitions in a simple frame language into objective functions whose minima correspond to partial deductive closures of the legaJ inferences. The resulting constrained optimization problem can be viewed as a specification for a connectionist network
IoT-Enabled Smart Healthcare Infrastructure Maximises Energy Efficiency
Advancements in IoT-based applications have become the cutting-edge technology among researchers due to the wide availability of the Internet. In order to make the application more user-friendly, Android-based and Web-based technologies have become increasingly important in this cutting-edge technology. Smart cities, Internet of Things(IoT), Smart health care systems are the technology of the future. A combination of numerous systems focusing on monitoring different components of the smart city (such as water, e-health, gas, power monitoring and emergency scenario detection) can be used to make the city more sustainable and secure. In smart cities, energy consumption is particularly important for e-health. An optimization approach is provided in this paper to reduce total network energy usage. When compared to previous methods, the overall performance has improved by 57.89%
Modified Context Aware Middleware Architecture for Precision Agriculture
The opportunities for researchers are enhanced with the progression in the technology of communication and computing. The ease in life of many people like farmers, educators, administers, managers, etc., is increased with more inventions of the researchers using this new technology. The progressive technology for data management is providing more amount of information. However, is the user able to access the needed information when required? This question rises to the more questions like, how to identify whether the information is as per the requirement? Whether a user is authorized or not? The answer for all the questions is to make the support aware of the context. Therefore, the present technology needs to be modified to make the system aware about the context. The process of demonstrating the services based on the context using Wireless Sensor Networks (WSN) with the help of illustration on mango crop is emphasized in this paper. There are many serious problems like unsuitable fertilizer use, wrong selection of crops in wrong seasons, water waste, poor publicizing in the case of farming. These problems are addressed using the ubiquitous context aware middleware architecture for precision agriculture in mango crop
On the Interpretation of Energy as the Rate of Quantum Computation
Over the last few decades, developments in the physical limits of computing
and quantum computing have increasingly taught us that it can be helpful to
think about physics itself in computational terms. For example, work over the
last decade has shown that the energy of a quantum system limits the rate at
which it can perform significant computational operations, and suggests that we
might validly interpret energy as in fact being the speed at which a physical
system is "computing," in some appropriate sense of the word. In this paper, we
explore the precise nature of this connection. Elementary results in quantum
theory show that the Hamiltonian energy of any quantum system corresponds
exactly to the angular velocity of state-vector rotation (defined in a certain
natural way) in Hilbert space, and also to the rate at which the state-vector's
components (in any basis) sweep out area in the complex plane. The total angle
traversed (or area swept out) corresponds to the action of the Hamiltonian
operator along the trajectory, and we can also consider it to be a measure of
the "amount of computational effort exerted" by the system, or effort for
short. For any specific quantum or classical computational operation, we can
(at least in principle) calculate its difficulty, defined as the minimum effort
required to perform that operation on a worst-case input state, and this in
turn determines the minimum time required for quantum systems to carry out that
operation on worst-case input states of a given energy. As examples, we
calculate the difficulty of some basic 1-bit and n-bit quantum and classical
operations in an simple unconstrained scenario.Comment: Revised to address reviewer comments. Corrects an error relating to
time-ordering, adds some additional references and discussion, shortened in a
few places. Figures now incorporated into tex
Continuous Time-Dependent Measurements: Quantum Anti-Zeno Paradox with Applications
We derive differential equations for the modified Feynman propagator and for
the density operator describing time-dependent measurements or histories
continuous in time. We obtain an exact series solution and discuss its
applications. Suppose the system is initially in a state with density operator
and the projection operator is measured
continuously from to , where is a projector obeying and a unitary operator obeying and some smoothness
conditions in . Then the probability of always finding from to is unity. Generically and the watched system is sure to
change its state, which is the anti-Zeno paradox noted by us recently. Our
results valid for projectors of arbitrary rank generalize those obtained by
Anandan and Aharonov for projectors of unit rank.Comment: 16 pages, latex; new material and references adde
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