Path Integral Approach to Levy Flights and Hindered Rotations
Electronic Theses of Indian Institute of Science
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Title |
Path Integral Approach to Levy Flights and Hindered Rotations
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Creator |
Janakiraman, Deepika
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Subject |
Path Integrals
Levy Noise Levy Flight Anomalous Diffusion Hamiltonian Path Integral Harmonic Oscillators - Path Integrals Barrier Crossing - Path Integrals Statistical Mechanics Hindered Rotors Friction (Levy Flights) Levy Flights - Path Integrals Hindered Rotations Quantum Mechanics |
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Description |
Path integral approaches have been widely used for long in both quantum mechanics as well as statistical mechanics. In addition to being a tool for obtaining the probability distributions of interest(wave functions in the case of quantum mechanics),these methods are very instructive and offer great insights into the problem. In this thesis, path integrals are extensively employed to study some very interesting problems in both equilibrium and non-equilibrium statistical mechanics. In the non-equilibrium regime, we have studied, using a path integral approach, a very interesting class of anomalous diffusion, viz. the L´evy flights. In equilibrium statistical mechanics, we have evaluated the partition function for a class of molecules referred to as the hindered rotors which have a barrier for internal rotation. Also, we have evaluated the exact quantum statistical mechanical propagator for a harmonic potential with a time-dependent force constant, valid under certain conditions. Diffusion processes have attracted a great amount of scientific attention because of their presence in a wide range of phenomena. Brownian motion is the most widely known class of diffusion which is usually driven by thermal noise. However ,there are other classes of diffusion which cannot be classified as Brownian motion and therefore, fall under the category of Anomalous diffusion. As the name suggests, the properties of this class of diffusion are very different from those for usual Brownian motion. We are interested in a particular class of anomalous diffusion referred to as L´evy flights in which the step sizes taken by the particle during the random walk are obtained from what is known as a L´evy distribution. The diverging mean square displacement is a very typical feature for L´evy flights as opposed to a finite mean square displacement with a linear dependence on time in the case of Brownian motion. L´evy distributions are characterized by an index α where 0 |
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Contributor |
Sebastian, K L
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Date |
2018-04-12T15:31:45Z
2018-04-12T15:31:45Z 2018-04-12 2013 |
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Type |
Thesis
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Identifier |
http://etd.iisc.ernet.in/2005/3396
http://etd.iisc.ernet.in/abstracts/4262/G25859-Abs.pdf |
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Language |
en_US
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Relation |
G25859
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