Bulletin of the American Physical Society
2019 Annual Meeting of the APS Far West Section
Volume 64, Number 17
Friday–Saturday, November 1–2, 2019; Stanford, California
Session H02: Astrophysics II |
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Chair: Patricia Sparks, Harvey Mudd College Room: Science Teaching and Learning Center STLC 115 |
Saturday, November 2, 2019 3:30PM - 3:42PM |
H02.00001: A tunable multi-rod resonant cavity for HAYSTAC Maria Simanovskaia Haloscope at Yale Sensitive To Axion Cold Dark Matter (HAYSTAC) is a dark matter detector that looks for an axion-induced power excess spectrally coincident with the resonance of a microwave cavity immersed in a strong magnetic field. The current HAYSTAC cavity achieves frequency-tunability over the 3.6-5.8 GHz window by a single, off-center tuning rod. However, probing higher frequencies introduces unique challenges. In particular, smaller volumes, lower quality factors, and higher densities of intruder modes decrease sensitivity and increase operational complexity. Here, we present the design and initial testing results of a cavity using seven tuning rods for the 5.5-7.4 GHz range. This design will allow HAYSTAC to probe higher axion masses while maintaining axion sensitivity significantly greater than that of the standard design. -/a [Preview Abstract] |
Saturday, November 2, 2019 3:42PM - 3:54PM |
H02.00002: Optimization of the DM Radio 50 L Magnet Design Aya Keller, Alexander Leder The nature of Dark Matter (DM) has been an outstanding problem in experimental particle physics for the past 80$+$ years, and attention has recently been turned to new DM candidates such as axions. The DM Radio experiment seeks to scan over a broad range of possible axion masses using a resonant approach with sensitive superconducting devices; the sensitivity for the DM Radio 50 L experiment hinges heavily on its magnet and scales as B*(V to the 5/6), where B is the peak magnetic field and V is the sensitive volume. In order to maximize the sensitivity reach of the DM Radio 50 L and successive DM Radio designs, we ran an optimization study that took into account the sensitive volume, total mass, and other parameters for the toroidal magnet shape. The main constraints for the design stemmed from physical limitations of the experimental setup, such as the total cooling power available in dilution refrigerators. The potential designs we obtained from these studies were used to investigate the trade-offs of varying limitations for certain parameters, with simulations confirming the numerical calculations. [Preview Abstract] |
Saturday, November 2, 2019 3:54PM - 4:06PM |
H02.00003: Design of the DM Radio Toroidal Magnet Cross Section Alexander Droster Dark Matter Radio (DM Radio) will use a toroidal DC magnetic field to probe axion dark matter in the sub-$\mu$eV mass range. In this talk we discuss the design of the toroidal magnet’s cross section. We conclude that a magnet with a D-shape cross section, similar to that of tokamak fusion reactors, offers the best performance both from the perspective of mechanical properties and for maximizing the predicted axion conversion power. We compare the D-shape design to comparable circular and rectangular cross section designs to quantify the performance advantage of the D-shape for key magnet properties. This study informs the design of the next step in the DM Radio program, DM Radio 50 Liter, which will implement a 50 L toroidal magnet to search for axion dark matter in the $\sim$10 neV to $\sim$1 $\mu$eV mass range. [Preview Abstract] |
Saturday, November 2, 2019 4:06PM - 4:18PM |
H02.00004: Light Dark Matter Search using radio-frequency data mined from the Green Bank Telescope (GBT) Adyant Kamdar In this work, we present our ongoing effort aimed at the indirect detection of light dark matter, such as hidden photons or axions, by searching for a power excess in the radio-frequency spectra of astrophysical objects in the galaxies of the Local Group, including our own. In particular, we utilize large data sets of radio spectral data recorded by the Green Bank Telescope (GBT) to cover frequencies in the 1-12 GHz regime. This talk will primarily focus on a description of the recently released public data sets, the preliminary steps of data analysis, i.e. curation and selection of the data, calibration, normalization, etc., and a preview of the actual analysis to be carried out initially. [Preview Abstract] |
Saturday, November 2, 2019 4:18PM - 4:30PM |
H02.00005: Applying the matched-filter technique to the search for dark matter transients with networks of quantum sensors Guglielmo Panelli, Benjamin Roberts, Andrei Derevianko Nearly two decades of high accuracy data from atomic clocks aboard the Global Positioning System (GPS) satellites is publicly available from the geoscience community. This archival data can be used for searches for exotic physics, such as direct dark matter searches. Here we explore the application of the matched-filter technique as a detection strategy for macroscopic dark matter objects sweeping through the GPS network. Such ``clumpy'' dark matter objects would register as transients passing through the network at galactic velocities. This sweep would result in a correlated propagation of atomic clock glitches in the archival GPS data. We apply the matched-filter technique to simulated GPS atomic clock data and study its utility and performance. The analysis and the developed methodology have a wide applicability to other networks of quantum sensors. [Preview Abstract] |
Saturday, November 2, 2019 4:30PM - 4:42PM |
H02.00006: Identifying the Quark-Hadron Phase Transition in Neutron Stars with $g$-modes Megan Barry, Prashanth Jaikumar, Thomas Klaehn, Wei Wei Containing the densest known matter in the universe, neutron stars provide a unique opportunity to study the properties of neutrons, protons, and possibly quarks. Their distance makes them difficult to observe, but their high density makes them good targets for gravitational wave observations. Fluid oscillations within the star, similar to earthquakes on earth, may be detectable through gravitational waves. One such type of oscillation, known as $g$-mode oscillations, has a frequency that depends on the material composition of the star. We propose a new dynamical signature for the presence of quark matter inside a neutron star, a steep rise in the frequency of stellar $g$-mode oscillations once quark matter appears in the core. The sensitivity of core $g$-mode oscillations to the presence of a mixed quark-hadron phase is a new finding. Based on its importance as an indicator of the QCD phase transition in neutron stars, we present an estimate for the phase shift of gravitational waveforms due to $g$-mode excitation during a binary merger. [Preview Abstract] |
Saturday, November 2, 2019 4:42PM - 4:54PM |
H02.00007: Creation Of Our Universe And Dark Energy Described Using Common Old 3D Physics Charles Sven The most important thing is what Feynman told us: ``All things are made of atoms.'' Today's cosmological concept is that our Universe's atoms were created from a `singleton' popping out of `nothing' and not well received. That indicates that we need a better explanation. We seek observational answers to questions of today using microscope and telescopes. Pertinent old facts allows us to understand atoms and how `physics' of dark energy was employed before, during, and after Big Bang. Assembling 13.8 billion year old spherical atoms into a match, when struck, emit light photons at 186,282 m/sec, indicating that \underline {some energy} must drive atom's electrons. A gram's worth of uranium atoms; redirects its power source in an atomic bomb. Both fission and fusion; \underline {redirects power in star's atoms}. Chaotic Dark Energy prior to Big Bang, converged and created matter just like at Stanford where atomic matter was created in 97. Based on above, plus more, we find that creation of our Universe was constructed out of chaotic Dark Energy --vast, powerful, and timeless, existing prior to Big Bang and continues to drive atoms based on all the stars shinning in all the galaxies in our Universe. [Preview Abstract] |
Saturday, November 2, 2019 4:54PM - 5:06PM |
H02.00008: The Growth of the Density Fluctuations in the Scale-Invariant Vacuum Theory Vesselin Gueorguiev, Andre Maeder The growth of the density fluctuations is an important cosmological test. In the standard EdS model the growth of the density perturbations evolves with redshift $z$ like $(\frac{1}{1+z})^s$ with $s=1$. Without the introduction of dark matter, this is not fast enough to form galaxies and to account for the observed present-day inhomogeneities. This view is challenged in the present paper [1] by using a Scale-Invariant Vacuum Theory (SIVT) as a framework for cosmology. From the continuity equation, the corresponding Euler and Poisson equations are written in the scale-invariant framework, the equation governing the growth of density fluctuations $\delta$ is obtained as well. Starting from $\delta = 10^{-5}$ at a redshift around 1000, numerical solutions for various density background are obtained. The growth of density fluctuations is much faster than in the standard EdS model. The $s$ values are in the range from 2. 7 to 3. 9 for $\Omega_{\mathrm{m}}$ between 0. 30 and 0. 02. This enables the density fluctuations to enter the nonlinear regime with $\delta > 1$ long before the present time, typically at redshifts of about 10, without requiring the presence of dark matter.\[\] [1] Physics of the Dark Universe $\textbf{25}$ (2019) 100315 (DOI: 10.1016/j.dark.2019.100315). [Preview Abstract] |
Saturday, November 2, 2019 5:06PM - 5:18PM |
H02.00009: Explanations for data about dark matter, dark energy, and galaxy formation Thomas J. Buckholtz We suggest descriptions for new elementary particles, dark matter, and dark energy. We use those descriptions to explain data regarding dark matter effects, dark energy effects, and galaxy formation. Our mathematics-based modeling, descriptions, and explanations embrace and augment traditional physics theory modeling. [Preview Abstract] |
Saturday, November 2, 2019 5:18PM - 5:30PM |
H02.00010: It from Bit or Them from Ylem? Richard Gauthier John Archibald Wheeler's phrase ``it from bit'' suggests that quantum mechanics and the explanation for physical existence may be based on information theory. According to this idea, physical reality may arise from yes-no binary outcomes in quantum measurement experiments, and perhaps from an even deeper information level. This article proposes another idea: that superluminal energy quanta embody the information needed to form the fundamental particles that produce our universe. Superluminal energy quanta were the primordial matter that produced the first hot plasma of fundamental particles during the Big Bang. One superluminal energy quantum may have formed the original primordial quantum particle that produced our universe -- the cosmic quantum, which is proposed to also be the first particle of dark matter. Superluminal energy quanta continue to form fundamental particles today such as photons and electrons. The primordial matter of the universe, traditionally called ylem, is proposed to be superluminal energy quanta that form the fundamental particles of our universe -- giving rise to the expression ``them from ylem''. [Preview Abstract] |
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