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.
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Showing 1 to 20 of 52 for “"gravitational potential"”.
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Constaints on the shape and scale of the galactic gravitational potential
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1994.
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The sum of the 1D magnifications along the axis of positive curvature for a smooth gravitational potential with N point perturbations
Gravitational lensing is an important tool for determining the matter content of the universe. The locations of gravitationally lensed images tend to give us information about the overall structure of a lensing galaxy, whereas the magnifications of the images tell us about small scale structure of …
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Accreted Globular Clusters in External Galaxies: Why Adaptive Dynamics won’t work
… cosmological problems require a well-determined gravitational potential. Globular clusters (GCs) surrounding galaxies can be used as dynamical tracers of the luminous and dark matter distribution at large (kpc) scales. This M.Sc. project investigates - by means of the Auriga galaxy simulations …
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Stability of flat galaxies
… the three-dimensional interaction through their gravitational potential.
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Weighing the Milky Way While Exploring Dynamical Disequilibrium
… that galaxies and galaxy clusters formed in gravitational potential wells defined by dark matter overdensities in the structural formation stage of the universe. Therefore, the decomposition of matter into baryonic and dark contributions is a fundamental problem for studies of galaxies. This …
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LOW-THRUST CONTROLLER FOR SLOT-BASED SATELLITE CONSTELLATIONS
… expected to continue in the future, which could potentially lead to an increased risk of collision between satellites. Collision avoidance is therefore paramount to maintain normal operations and to prevent runaway growth of space debris in LEO. To that end, this thesis develops state-space LQR …
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Galactic Dark Matter
… to each other as they both move in the same gravitational potential, constraints on the distribution and properties of dark matter can be derived by studying the distribution of visible matter in the Galaxy and making some general assumptions regarding the phase-space distribution of the dark …
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A Study on the Effect of Galactic Atmospheres on Shock Induced Disruption of Extragalactic Jets (Clusters, Galaxies, Winds, Cooling)
… by the energy balance of the gas in the gravitational potential defined by the galaxy. One finds that the gas environment or "atmosphere" around a galaxy can be described either as an outflowing "wind", in the case where heating dominates, or a "cooling" inflow, in the case where cooling …
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Calculation involving hydrogen-hydrogen(2) collisional cooling processes for use in astrophysics
… instance, in order to collapse into objects, the gravitational potential energy of primordial density fluctuations must be radiated away. The most abundant element in the universe is hydrogen, and cooling processes involving hydrogen are important in several contexts. To calculate the cooling, the …
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Infinite Derivative Gravity : a finite number of predictions
… cosmologists and experimentalists. First, the gravitational potential produced by a point source is derived and compared to experimental evidence, around both Minkowski and (Anti) de Sitter backgrounds. Second, the conditions necessary for avoidance of singularities for perturbations around …
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The effect of a low density residuum on geoid anomalies and topography
… topography, seismic wave speed, and the geoid (gravitational potential). High seismic wave speed indicates cold material sinking, which pulls the surface downward. Thus, topographic lows are expected to correlate with seismic wave speed highs, contrary to the new seismic measurements. We propose …
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Correcting the rotation curve of spiral galaxies for the non-circular motions induced by a bar
… and that this motion traces the underlying gravitational potential. In the case of barred spiral galaxies the first assumption is false as the bar induces non-circular streaming motions in the gas. Therefore, the rotation curves of barred galaxies need to be corrected for the non-circular …
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Classical, quantum and numerical aspects of modified theories of gravity
… spin-0 particles. We derive the corresponding gravitational potential energy for the non-static case and show that the quantum correction of the local theory, which is in the form of a Dirac delta function, is smeared out in the non-local theory. It is also shown that the gravitational …
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Source Parameters and Tectonic Setting of the 2017 St. Elias Earthquake Sequence near the Southern Terminus of the Eastern Denali Fault, Northwestern Canada
… developed to explain the observations, wherein gravitational potential from the >4,000 m high Mount Fairweather, as well as strain partitioning along the plate boundary, produce a stress regime that extends inboard towards the EDF.
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Gravitational influences on magnetic field structure in accretion disks
… is explored via a higher-order expansion of the gravitational potential. We consider several cases: the case when the Lorentz force is negligible and the case when the Lorentz force becomes significant in the dynamics of the disk. When the Lorentz force is negligible, we find using the Ferraro …
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The nucleus of Centaurus A
… data are crucial to identify non-gravitational gas motions. The H2 gas kinematics inside the central r<1.5 arcsec of the active galactic nucleus are successfully described by a (warped) gas disk, rotating in the joint gravitational potential of the stars and a black hole of …
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Rapid Middle to Late Miocene Slip Along the Zanskar Normal Fault, Greater Himalayan Range, NW, India: Constraints from Low-Temperature Thermochronometry
… channel flow mechanism and/or by an increase in gravitational potential energy as a consequence of a slab break-off event.
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Multifaceted Understanding of Accreting Neutron stars and their Environments
… neutron stars peak in the X-rays, owing to gravitational potential energy loss as the accreting material falls under the strong gravitational well of the neutron star. The community has been utilizing X-ray timing and spectroscopy for decades to unravel the mysteries of these objects, with …
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Spectroscopic surface brightness fluctuations
… to measure the kinematics and than model the gravitational potential using these exceptionally high-quality data. In the second part I develop the new method of surface brightness fluctuation spectroscopy and quantitatively explore its potential to investigate the bright evolved stellar …
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Submillimetre Studies of Pre-stellar and Starless Cores in the Ophiuchus, Taurus and Cepheus Molecular Clouds
… that most cores are either bound or virialised. Gravitational potential and external pressure energies are found to be typically of a similar order of magnitude, with some variation between regions. Non-thermal linewidths decrease between C18O-traced and N2H+-traced material, indicating …
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