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Full-Text Articles in Physics

Screening And Plasma Oscillations In An Electron Gas In The Hydrodynamic Approximation, Eugene B. Kolomeisky, Joseph P. Straley Oct 2017

Screening And Plasma Oscillations In An Electron Gas In The Hydrodynamic Approximation, Eugene B. Kolomeisky, Joseph P. Straley

Physics and Astronomy Faculty Publications

A hydrodynamic theory of screening in a generic electron gas of arbitrary dimensionality is given that encompasses all previously studied cases and clarifies the predictions of the many-body approach. We find that long-wavelength plasma oscillations are classical phenomena with quantum-mechanical effects playing no explicit role. The character of the oscillations is solely dictated by the dimensionality of the electron system and its equation of state in the neutral limit. Materials whose excitations are described by the Dirac dispersion law—such as doped graphene or a Weyl semimetal—are no exception to this rule.


The Formation And Dynamics Of Clouds In The Environment Of Active Galactic Nuclei, Timothy Waters Aug 2017

The Formation And Dynamics Of Clouds In The Environment Of Active Galactic Nuclei, Timothy Waters

UNLV Theses, Dissertations, Professional Papers, and Capstones

Active galactic nuclei (AGN) are among the most luminous objects in the universe and are known to be powered by accretion onto supermassive black holes in the centers of galaxies. AGN clouds are prominent components of successful models that attempt to unify the diversity of AGN. These clouds are often hypothesized to be the source of the broad and narrow line emission features seen in AGN spectra. Moreover, the high column densities of gas needed to account for broad absorption lines has been attributed to the same population of clouds, while the motion of AGN clouds has been invoked to …


How Hospitable Are Space Weather Affected Habitable Zones? The Role Of Ion Escape, Vladimir S. Airapetian, Alex Glocer, George V. Khazanov, Robert O Parke Loyd, Kevin France, Jan Josef Sojka, William C. Danchi, Michael W. Liemohn Feb 2017

How Hospitable Are Space Weather Affected Habitable Zones? The Role Of Ion Escape, Vladimir S. Airapetian, Alex Glocer, George V. Khazanov, Robert O Parke Loyd, Kevin France, Jan Josef Sojka, William C. Danchi, Michael W. Liemohn

All Physics Faculty Publications

Atmospheres of exoplanets in the habitable zones around active young G-K-M stars are subject to extreme X-ray and EUV (XUV) fluxes from their host stars that can initiate atmospheric erosion. Atmospheric loss affects exoplanetary habitability in terms of surface water inventory, atmospheric pressure, the efficiency of greenhouse warming, and the dosage of the UV surface irradiation. Thermal escape models suggest that exoplanetary atmospheres around active K-M stars should undergo massive hydrogen escape, while heavier species including oxygen will accumulate forming an oxidizing atmosphere. Here, we show that non-thermal oxygen ion escape could be as important as thermal, hydrodynamic H escape …


Dynamic Fluctuations From Hydrodynamics And Kinetic Theory In High Energy Collisions, Christopher David Zin Jan 2017

Dynamic Fluctuations From Hydrodynamics And Kinetic Theory In High Energy Collisions, Christopher David Zin

Wayne State University Dissertations

It is well accepted that heavy ion collisions can be described using hydrodynamic theory, implying these systems are large enough and long lived enough to reach local equilibrium. Recent measurements of correlations in pA and high multiplicity pp collisions at the Relativistic Heavy Ion Collider and Large Hadron Collider have shown that these systems also exhibit signs of thermalization, unexpected in the smaller, shorter lived systems. Studying this behavior can give insight into the thermalization process and help clarify the relationship between flow in large systems and hydrodynamics. In an effort to understand these measurements we use the Boltzmann equation, …