Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 88 for “"Scattering Theory"”.
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Time delay in nuclear scattering theory
Typewritten
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Broadband microwave inverse scattering: Theory and experiment
… for performing broadband time-domain inverse scattering. The inverse scattering problem is very important for a number of application areas including nondestructive evaluation, geophysical probing, medical imaging and military target identification. Emphasis is placed on the use of microwaves …
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Scattering theory approach to electrodynamic Casimir forces
… combines each object's classical electromagnetic scattering amplitude with universal translation matrices, which convert between the bases used to calculate scattering for each object, but are otherwise independent of the details of the individual objects. The method is illustrated by rederiving …
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Scattering theory on compact manifolds with boundary
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1993.
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The Born-Oppenheimer approximation in scattering theory
We analyze the Schrödinger equation i𝜖 ¬<sup>2</sup>â /â tΨ = H(𝜖)Ψ, where H(â ¬) = - f24 Î x + h(X) is the hamiltonian of a molecular system consisting of nuclei with masses of order 𝜖¬<sup>-4</sup> and electrons with masses of order 1. The Born-Oppenheimer approximation consists of the …
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Topics in Electromagnetic, Acoustic, and Potential Scattering Theory
… and invisibility, the topic of time-independent scattering theory in quantum mechanics is becoming a useful field to re-examine in the above contexts. One of the key areas of electromagnetic theory scattering of plane electromagnetic waves — is based on the properties of the refractive indices in …
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Accurate Quantum Mechanical Decoupling Approximations for Molecular Scattering Theory
Recent work is reviewed on the theory of angular momentum decoupling approximations in inelastic molecular scattering theory. It is shown that the failure of these approximations is more extensive than previously believed, particularly for completely state-selected m-transitions. A new method is …
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Quantum mechanical molecular scattering theory: Orbiting to room temperature
A series of time-independent scattering calculations were done on the helium and silicon-monoxide (B =.0901 meV) system in its ground electronic state using the rigid rotor approximation. Close Coupling results were compared with those of the L-average form of Coupled States (CS), its first order …
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Scalar Scattering Theory and Physics-inspired Optimization for Computational Imaging
… critical problems of phase retrieval and optical scattering—essential for accurately extracting physical information from photons. It aims to enhance the understanding and computational efficiency of existing models by addressing the fundamental challenges encountered due to diffraction effects, …
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Molecular partitioning and approximate coupling techniques in multiple scattering theory
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1984.
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Wave propagation in complex media, scattering theory, and application to seismic imaging
… is essentially equivalent to solving an inverse scattering problem in structurally complex media. Conventional migration algorithms rely on linearized inversion schemes and assume single-scattering dominance. The primary focus of this thesis is an alternative nonlinear scattering-based approach …
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Inverse scattering : theory and application to the imaging of the Earth's seismic discontinuities
… thesis we further develop concepts in inverse scattering, which enable higher resolution imaging with data from dense networks and arrays. We apply the new methods to studies of the crust beneath south Tibet and the core-mantle boundary (CMB) region beneath Central America and East Asia. First, …
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A Curvature-Corrected Rough Surface Scattering Theory Through The Single-Scatter Subtraction Method
… to study radio propagation and rough surface scattering problems based on a reformulation of the Magnetic Field Integration Equation (MFIE) called the Single-Scatter Subtraction (S^3) method. This technique amounts to a physical preconditioning by separating the single- and multiple-scatter …
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A Scattering Theory for Linearised Gravity on the Exterior of the Schwarzschild Black Hole
In this thesis we construct a scattering theory for the linearised Einstein equations on a Schwarzschild background in a double null gauge. We perform this construction in two parts. In Part I, we construct a scattering theory for the spin ±2 Teukolsky equations, which govern certain the extremal, …
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Models for sound propagation in suspensions and emulsions
… Three theoretical approaches are identified: scattering theory, coupled phase theory and porous media theory. Coupled phase theory is extended and compared analytically and numerically to scattering and porous media theory. Important regimes of scattering theory - the lossless and viscothermal …
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EVALUATING THE USE OF TURBIDIMETRY FOR STUDYING FIBRIN STRUCTURAL PROPERTIES
… of fibers is turbidimetry, which uses light scattering theory for randomly oriented, thin, cylindrical rods to estimate fibrin fiber structural properties from scattering data. There are several different approaches that use turbidimetry to solve for these parameters, each of which has …
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Toward a Rigorous Justification of the Three-Body Impact Parameter Approximation
… is a semiclassical model in quantum scattering theory wherein N large masses interact with one small mass. We study this model in one spatial dimension using the tools of time-dependent scattering theory, considering a system of two large-mass particles and one small-mass particle. We …
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Semiclassical Scattering for Two and Three Body Systems
Semiclassical scattering theory can be summarized as the study of connections between classical mechanics and quantum mechanics in the limit ℏ → 0 over the infinite time domain -∞ < t < ∞. After a brief discussion of Semiclassical Analysis and Scattering Theory we provide a rigorous result …
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Nanostructures and alloys : multiple scattering and nonlinearities in phonon transport
… and dielectrics. Effective field theories and scattering theory have been combined to model alloys and systems with embedded nanostructures. The simplest of such effective field theories, the Virtual Crystal approximation, fails to capture short-length scale information due to the inherent …
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The effect of surface roughness on thermal and acoustic phonon transport in nanowires and nanomembranes
… the experiments are interpreted through wave scattering theory. This work investigates Si nanowires and nanomembranes with characteristic sizes smaller than 200 nm. Using a MEMS-based measurement platform, we observe the low-temperature dependence of thermal conductivity in silicon nanowires …
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