Bulletin of the American Physical Society
82nd Annual Meeting of the APS Southeastern Section
Volume 60, Number 18
Wednesday–Saturday, November 18–21, 2015; Mobile, Alabama
Session H2: Astrophysics and General Relativity |
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Chair: Justin Sanders, University of South Alabama Room: Riverview Plaza Hotel Mobile Bay Ballroom I |
Friday, November 20, 2015 1:30PM - 1:42PM |
H2.00001: The Advanced LIGO Detector and Seismic Noise Christopher Buchanan The Advanced LIGO project has recently started its first observation run with newly upgraded ultra-high sensitivity gravitational wave detectors (one in Louisiana, and another in Washington). The basic design of these detectors is a Michelson-Morley interferometer, with Fabry-Perot cavities in each arm. We also rely on sophisticated instrumentation and subsystems, such as high-isolation multi-stage suspensions and additional optical cavities, in order to operate at a sensitivity necessary to detect gravitational waves. These very small fluctuations in space-time are produced by astrophysical sources (e.g. the inspiral of two neutron stars), and these detectors are likely to provide the first direct detection of gravitational waves in the next few years. My work focuses on characterizing sensitivity-limiting noise in low frequencies, where seismic effects (earthquakes, tides, local traffic, etc.) dominate. A good understanding of the spectral and time characteristics of this noise helps us to optimize data analysis methods in this regime and to improve and maintain an optimum state of the detector. [Preview Abstract] |
Friday, November 20, 2015 1:42PM - 1:54PM |
H2.00002: Characterization of the Diagnostics of the Inductively Heated Plasma Generator (IPG6-B) Joshua Edgren, Kathryn Clements, Michael Dropmann, Rene Laufer, Truell Hyde, Lorin Matthews The Inductively heated plasma generator (IPG6B) at the Center for Astrophysics, Space Physics, and Engineering Research (CASPER) at Baylor University provides valuable insight into the nature of high-enthalpy plasma flows in Helium, argon, and nitrogen. The device and its diagnostics have yet to be characterized. In order for the device to be useful for reentry simulations or for fusion reactor materials testing, a thorough map of its behavior at a wide range of pressures and gas flows were investigated. For this reason various experiments have been performed with a cavity calorimeter in order to determine the plasma power at distinct parameters. Although there is considerable work yet to do, the results have demonstrated trends in the devices behavior which will allow optimal operating conditions to be inferred. Additionally over the course of the analysis of these experiments, a Matlab algorithm was written to isolate stable regions of data and extrapolate equilibrium values and time constants from them. This quantifies the time required for experimental measurements to reach equilibrium after experimental parameters have been changed. [Preview Abstract] |
Friday, November 20, 2015 1:54PM - 2:06PM |
H2.00003: Neutron-mirror neutron oscillations in a residual gas environment Louis Varriano, Boris Kerbikov, Yuri Kamyshkov Both mirror matter, a candidate for dark matter, and ordinary matter can have similar properties and self-interactions but will interact only gravitationally with each other, in accordance with observational evidence of dark matter. Although mirror matter does not couple to ordinary matter by Standard Model interactions, some additional interactions might exist, providing small mixing of ordinary matter neutral states, like the neutron, with mirror components. Three separate experiments have been performed in the last decade to detect the possibility of neutron-mirror neutron oscillations. In the analysis of the data of these experiments, the effect of the presence of residual gas (due to an imperfect vacuum) was not considered. This work provides a formalism for understanding the interaction of the residual gas in an experiment with ultra-cold neutrons. This residual gas effect that was previously considered as negligible can have a significant impact on the probability of neutron to mirror neutron transformation. This formalism is used to evaluate the three previous experiments and can provide a framework for the future mirror matter search experiments. [Preview Abstract] |
Friday, November 20, 2015 2:06PM - 2:18PM |
H2.00004: A Singular Value Decomposition of 15M Chimera Entropy Data Brandon Barker, Jesse Buffaloe, Eirik Endeve, Anthony Mezzacappa, Eric Lentz Core collapse supernovae are characterized by muti-dimensional dynamics. Studies have shown that the shock formed at core bounce always stalls. Until the development of axisymmetric (2D) simulations, little progress towards reviving the shock had been made. Modern simulations have given rise to the idea that both neutrino driven convection and the standing accretion shock instability (SASI) play pivotal roles in reviving the stalled shock. These mechanisms can increase the time material spends in the gain layer. The gain layer, the region near the stalled shock where net neutrino heating occurs, is dominated by turbulent flow. The turbulence in this region is necessary for maximizing the efficiency of the neutrino heating mechanism. Much of modern supernova theory is concerned with which of these two mechanisms plays a larger role in the revival of the stalled shock. We attempt to employ a singular value decomposition (SVD) in order to explore the relative contributions of the neutrino driven convection and SASI mechanisms. [Preview Abstract] |
Friday, November 20, 2015 2:18PM - 2:30PM |
H2.00005: Conservative Transformation Group: Solar System Dynamics Edward Green Pandres has proposed a theory which extends the geometrical structure of a real four-dimensional space-time via an enlarged transformation group called the conservation group. Using a contraction of the curvature vector, a Lagrangian is defined and the resulting field equations are invariant under the conservation group. We use the free-field spherically symmetric solutions to explore the implications for solar system dynamics. These solutions are similar but not identical to those of standard General Relativity. Radial motion, the Pioneer anomaly, Kepler's third law, the precession of perihelia, gravitational lensing and the time-delay problems are discussed and compared to the standard results. Possible solutions for the Pioneer anomaly and the temperature of the halo are presented. [Preview Abstract] |
Friday, November 20, 2015 2:30PM - 2:42PM |
H2.00006: Constraining ghostfree covariant theories of gravity with light bending experiments Richard Bustos Modifications of Einstein's theory of General Relativity (GR) are notorious for introducing ghosts and tachyons which renders these theories classically unstable and any attempts to quantize them doomed to fail. Over the last few years, concrete criteria on covariant modifications to GR have been derived that ensures that the gravitational theory is free from such instabilities, at least, around the Minkowski vacuum. The most general consistent action can be parameterized by two mass scales: the first one controls the scale of nonlocality in the graviton interaction, and the second characterizes the mass of a Brans-Dicke type scalar mode that can be present in the metric tensor. Our goal has been to develop techniques to directly constrain these mass parameters from experimental tests of GR. In particular, I will talk about the constraints from the light bending experiments. [Preview Abstract] |
Friday, November 20, 2015 2:42PM - 2:54PM |
H2.00007: Conservative Transformation Group: Dark Matter Halos Edward Green Pandres has proposed a theory which extends the geometrical structure of a real four-dimensional space-time via a field of orthonormal tetrads with an enlarged transformation group. This new transformation group, called the conservation group, contains the group of diffeomorphisms as a proper subgroup and we hypothesize that it is the foundational group for quantum geometry. The fundamental geometric object of the new geometry is the curvature vector, $\mathrm{C}_{\mathrm{\mu }}$. Using the scalar Lagrangian density, $\mathrm{C}^{\mathrm{\mu }}C_{\mu }\sqrt {-g\thinspace } $ field equations for the free field have been obtained which are invariant under the conservation group. We present spherically symmetric solutions for the corresponding free field and a solution similar to the external Schwarzschild solution is obtained. The theory implies that the external stress-energy tensor has non-compact support and hence may give the geometrical foundation for dark matter. Flat velocity curves are obtained under suitable thermodynamic conditions. [Preview Abstract] |
Friday, November 20, 2015 2:54PM - 3:06PM |
H2.00008: A Two-Step Integrated Theory of Everything (TOE) Antonio Colella Two opposing TOE visions are, a Two-Step (physics and math) Integrated TOE and Hawking's single math step. The physics step defines relationships between 8 theories: string, particle creation, Higgs forces, spontaneous symmetry breaking, DE, DM, stellar black holes, and Super Universe. Matter/force particles are Planck cube strings. At t $=$ 0, matter/forces were super force strings in a singularity. Matter creation was a super force's condensation to a matter/Higgs force. Spontaneous symmetry breaking was bidirectional, a matter/Higgs force also evaporated to super force. Three types of permanent matter/forces were: atomic/subatomic matter (up quark, down quark, electron, and 3 neutrino types); DM (zino, photino, and 3 Higgsino types); and DE (8 Higgs forces of up quark, down quark, electron, 3 neutrino types, zino, and photino). Stellar black holes were a quark star (matter) and black hole (energy) composed of Planck cube matter/force strings. In our precursor universe, a quark star (matter) instantaneously evaporated, deflated, and collapsed to its black hole's (energy) singularity creating our universe. String theory unified Planck cube matter/force strings (quantum theory) with infinitely large quark stars (matter) (Einstein's GR). [Preview Abstract] |
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