Bulletin of the American Physical Society
2014 Annual Meeting of the Far West Section of the APS
Volume 59, Number 14
Friday–Saturday, October 24–25, 2014; Reno, Nevada
Session H1: Astrophysics and Gravitation |
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Chair: Douglas Singleton, California State University, Fresno Room: JCSU 320 |
Saturday, October 25, 2014 2:00PM - 2:12PM |
H1.00001: \textit{Ab initio} Study of Cyclopropenone Formation in Interstellar Space Seyedsaeid Ahmadvand, Ryan Zaari, Sergey Varganov The recent discoveries of complex organic molecules such as cyclopropenone and glycoaldehyde in interstellar space have renewed the interest in astrochemical reaction mechanisms. We investigate three previously proposed reaction mechanisms for cyclopropenone formation in interstellar medium using ab initio quantum chemical methods. The nonadiabatic spin-forbidden reaction between atomic oxygen and cyclopropenylidene characterized by very small activation barrier and significant spin-orbit coupling between the lowest energies singlet and triplet states. We calculate the Landau-Zener probability of transition between the triplet and singlet states, and use nonadiabatic transition state theory to estimate the reaction rate constant of this spin-forbidden reaction. The reaction between acetylene and carbon monoxide, and between molecular oxygen and cyclopropenylidene, are two spin-allowed cyclopropenone formation pathways, also investigated in this work. Of the three studied reactions, the most probable mechanism of cyclopropenone formation in cold regions of interstellar space is between molecular oxygen and cyclopropenylidene since it is found to be a barrier free reaction. [Preview Abstract] |
Saturday, October 25, 2014 2:12PM - 2:24PM |
H1.00002: Improvement in applying observations to understanding glitches in pulsars Sabrina Berger, William Newton Some pulsars exhibit glitches - sudden decreases in period every few years - that may arise from the interactions between the neutron star crust and core. By comparing the predictions of theoretical models to empirical data of glitches, we hope to resolve the details of the glitch mechanism and constrain the underlying nuclear matter equation of state (EOS). The basic glitch paradigm supposes some part of the crust does not spin down with the rest of the star until a critical lag between the frequency of that part of the crust and the core is reached, at which point angular momentum is transferred from crust to core, spinning the star up. We focus on model predictions of how strongly the crust couples to the core: this determines how much of the core gets spun up and can be tested by data from the Vela pulsar. The crust and core couple via mutual friction, in which electrons scatter off of magnetized superfluid neutron vortices in the core. We generate many EOSs spanning the current range of uncertainty in the nuclear symmetry energy and consistently calculate the strength of mutual friction throughout the core of the neutron star for each EOS. We find that, considering the most conservative range of EOSs, the crust cannot provide a large enough angular momentum reservoir to explain the Vela data, and that the crust-core coupling model therefore has to be revised. [Preview Abstract] |
Saturday, October 25, 2014 2:24PM - 2:36PM |
H1.00003: Mapping the cloudy skies of the galactic black hole Cyg X-1 Natalie Hell, G.V. Brown, J. Wilms, I. Miskovicova, M. Hanke, J. Clementson, P. Beiersdorfer, D. Liedahl, K. Pottschmidt, F.S. Porter, C.A. Kilbourne, R.L. Kelley, V. Grinberg, M.A. Nowak, N.S. Schulz The high mass X-ray binary Cyg X-1 consists of a black hole (BH) and its supermassive companion star. The system's X-ray emission is powered through accretion of the companion's strong stellar wind that is focused onto the BH. Observational evidence suggests that the wind is a two-component medium: clumps of cooler and denser material embedded in tenuous hot gas. The clumps passing through our line of sight cause strong flux reductions (dips) in the observed lightcurves. While the absorption lines of He- and H-like ions in the spectra extracted from the dip-free phases are signatures of the hot gas, the cooler clumps cause additional absorption from lower ionized Si and S. Reliable atomic data are needed to derive Doppler shifts for these spectral lines, but the predicted uncertainty for the theoretical calculations is on the order of the expected shifts. We measured the K-shell transitions in L-shell Si and S ions at the LLNL electron beam ion trap. Combining the new reference data with the spectral signature of the clumps across various orbital phases allows us to map the clump distribution around the BH. [Preview Abstract] |
Saturday, October 25, 2014 2:36PM - 2:48PM |
H1.00004: Testing General Relativity with Continuous Gravitational Wave Polarizations Maximiliano Isi, Alan Weinstein, Carver Mead, Matthew Pitkin The direct detection of gravitational waves with the next generation detectors, like Advanced LIGO, provides the opportunity to measure deviations from the predictions of General Relativity. One such departure would be the existence of alternative polarizations. To measure these, we study a single detector measurement of a continuous gravitational wave from a triaxial pulsar source. We develop methods to detect signals of any polarization content and distinguish between them in a model independent way. [Preview Abstract] |
Saturday, October 25, 2014 2:48PM - 3:00PM |
H1.00005: Van der Waals Plasma Universe During Reissner-Nordstrom Expansion Vesselin Gueorguiev, Emil Prodanov, Rossen Ivanov A two-component gas, consisting of ultra-relativistic ``normal'' particles with specific charge~$q$/$m$ and ``unusual'' particles with ultra-high charge $Q$ and ultra-high mass $M $described by a Reissner--Nordstr\"{o}m metric, is conceived as a van der Waals gas model of a plasma in early Universe. The model gives rise to an expansion process, Reissner-Nordstrom Expansion, that is analogues to a cosmic expansion during the radiation-dominated era. The Reissner-Nordstrom Expansion is due to the presence of a region with ``gravitational repulsion'' of the Reissner--Nordstr\"{o}m metric with respect to the ``normal'' particles with \textit{sign}($Q)q$/$m \ge -$1. The expansion era naturally ends at recombination. We discuss the equation of state of the two-component van der Waals gas and the range of model parameters within which the proposed expansion process is consistent with the restrictions regarding quantum effects. [Preview Abstract] |
Saturday, October 25, 2014 3:00PM - 3:12PM |
H1.00006: Experimental Progress on Tests of Gravity at 20 microns Michael Ross, Crystal Cardenas Due to the incompatibility of the Standard Model and General Relativity, tests of gravity remain at the forefront of experimental physics research. At Humboldt State University, undergraduates and faculty are developing an experiment that will test gravitational interactions at the twenty-micron distance scale. The experiment will measure the twist of a torsion pendulum as an attractor mass is oscillated nearby in a parallel-plate configuration which will provide a time varying torque on the pendulum. The size and distance dependence of the torque variation will provide means to determine deviations from accepted models of gravity on untested distance scales. This talk will provide a general overview of the experiment, as well as address the measurement and characterization of environmental systematic effects that must be understood in order to achieve the required sensitivity. [Preview Abstract] |
Saturday, October 25, 2014 3:12PM - 3:24PM |
H1.00007: Gravitational Origin of the Higgs Boson Mass F. Winterberg With a positive-negative Planck mass plasma vacuum model I was able to predict a firewall at the event horizon of a black hole in a paper published in 2001 [1]. This same model can explain the Higgs boson as a particle made up from a very large positive mass ($+$10$^{13}$ GeV) quasiparticle gravitationally interacting with a likewise very large negative mass (-10$^{13}$ GeV) quasiparticle of this plasma, resulting in a spin 0 bound state of the positive and negative mass~quasiparticles with an energy of the right order of 10$^{2}$ GeV to explain the Higgs boson mass as the positive gravitational interaction energy of a very large positive with a very large negative mass [2]. \\[4pt] [1] F. Winterberg and Z. Naturforsch, Physical Sciences, 56a, 889 (2001);\\[0pt] [2] 69a, 220 (2014) [Preview Abstract] |
Saturday, October 25, 2014 3:24PM - 3:36PM |
H1.00008: Energy and the Variational Principle in New Massive Gravity (NMG) Colin Cunliff New Massive Gravity (NMG)---a particular massive theory of gravity that is fourth order in derivatives of the metric---formulated around a three-dimensional anti-de Sitter ($AdS_3$) background faces two major problems. In general, higher-derivative Lagrangians generate unwanted boundary terms that spoil the variational principle. Additionally, global charges---including the mass and angular momentum of black holes---diverge in asymptotically $AdS_3$ spacetimes in the absence of a well-defined renormalization procedure. This talk shows how both problems can be resolved with the addition of boundary terms to the action of new massive gravity. [Preview Abstract] |
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