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 E04: Gravitation 
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Chair: Douglas Singleton, California State University, Fresno Room: Science Teaching and Learning Center STLC 118 
Saturday, November 2, 2019 8:30AM  8:42AM 
E04.00001: MultiMode Apparatus to Determine Newton's Constant G Emily Ord, Ricardo Decca, Stefan Ballmer, C.D. Hoyle, Muchuan Hua The Newtonian gravitational constant, G, is a fundamental constant in nature not linked~by any complete theories to other forces of nature. Compared to all other fundamental constants, G is known with the least precision. Over the last 200 years, its~value~has~been~repeatedly~measured, and even the world's~leading~experiments have produced values which are incompatible with one another. In fact, compared to the most precise experiment,~some measured values differ by~up to~50 times the experimental~uncertainty. Recently, two experiments have measured consistent results at the 12 ppm level. After examination of the methodology used in previous measurements, the research group at IUPUI, in collaboration with Humboldt State University and Syracuse University, will use~multiple~approaches to determine G within a same torsion pendulum apparatus. We expect to obtain a measurement at the 2 ppm level using these new~methods. By continuing the use of a torsion pendulum apparatus, we also hope to better understand the current discrepancies among previous experimental~results. This talk will explore the experimental configurations and give a current update on the multimode apparatus. [Preview Abstract] 
Saturday, November 2, 2019 8:42AM  8:54AM 
E04.00002: Gravitational Compensation for a LaboratoryScale Test of the Equivalence Principle Kassandra Weber, Erik Shaw, John Lee, Charlie Hagedorn, Krishna Venkateswara, Jens Gundlach, Eric Adelberger Certain quantum theories that seek to unify the Standard Model and General Relativity put in to question the validity of the Weak Equivalence Principle (WEP), which states that the laws of relativity hold at every distance scale. Some of these theories require violations of the WEP. To search for these possible violations, the University of Washington's E\"{o}tWash group uses a rotating torsion balance that provides the most precise smallscale laboratory measurements of the WEP. Environmental factors surrounding the lab cause the largest systematic effect in this experiment by creating gravitational coupling between environmental field gradients and the multipole moments of the pendulum. Compensators have been constructed to minimize the strength of the q21, q22, and q31 multipole interactions on the pendulum due to these factors. This talk will focus on the development of an external mass distribution that provides improved compensation of the gravitational couplings, thereby allowing for a more precise measurement to be made. [Preview Abstract] 
Saturday, November 2, 2019 8:54AM  9:06AM 
E04.00003: Current Advancements on Shortrange Tests of Gravity at Humboldt State University. Darian Karadjov, Adam Turk, Alyssa Johnson, Berlin Del Aguila, Emily Ord, Frank Trombetta, Kassandra Weber, C.D. Hoyle As a result of discrepancies between the Standard Model and General Relativity, gravitational experiments have remained at the forefront of experimental physics research in an effort to unify these models. Theories which attempt this unification often include features that violate the Weak Equivalence Principle (WEP) and/or the gravitational InverseSquare Law (ISL), potentially bringing our fundamental understanding of gravity into question. Therefore, students, faculty and Humboldt State University have constructed an apparatus that will measure the effects of gravity at a submillimeter scale. This experiment measures the twist of a torsion pendulum as an attractor mass is oscillated nearby, providing a timevarying torque on the pendulum. In the experiment, the size and distance dependence of the torque are measured, thereby providing means to determine deviations from accepted models of gravity on untested distance scales. As with all gravitational experiments, characterization of systematic effects due to environmental fluctuations is paramount. This talk will focus on the improvements made to the physical apparatus as well as a brief discussion involving work done to compare the experimental model to a theoretical model. [Preview Abstract] 
Saturday, November 2, 2019 9:06AM  9:18AM 
E04.00004: Characterizing Crystallization at Higher Temperatures in Nanolayered Dielectric Coatings to Improve Mirrors in GravitationalWave Detectors Bhavna Nayak, Seth Linker, Tim Bennett, John Tamkin, Joshua Neilson, Brecken Larsen, Stephan LeBohec, Harry Themann, Yangyang Liu, Marina Mondin, Riccardo DeSalvo Gravitational waves emitted from massive astrophysical events induce a strain in spacetime that stretches our detectors by 10$^{\mathrm{19}}$m. Since the detectors need high sensitivity to detect this distortion, there's an urgent need to limit sources of noise, one such being the mirror coatings in the detectors. Imperfections like crystalline regions in uniform glassy coatings act as scatterers and greatly reduce sensitivity to gravitational waves either by direct loss of light or by mechanical dissipation, leading to thermal noise. Currently, coatings of tantala and silica are annealed to decrease light absorption. However, annealing leads to crystallite formation in the coatings and, therefore, higher mechanical loss. Our experiment aims to reduce crystallization by using nanolayers of titania and silica. It's been shown that crystallite size is limited by layer thickness. We annealed samples containing titania nanolayers of varying thickness and have observed that thinner layers crystallize at higher temperatures, which is indicative of crystallite suppression. We hope to find the optimal thickness in which no crystallites are formed even at very high annealing temperatures. [Preview Abstract] 
Saturday, November 2, 2019 9:18AM  9:30AM 
E04.00005: Quantum approach to F(R) gravity with fessence Mussat Imankul, Shynaray Myrzakul In recent years, due to the rapid development of astrophysics and the capabilities of modern technologies, a huge amount of astronomical data such as type Ia supernova, cosmic microwave background anisotropy (CMB), acoustic baryon oscillations, weak lensing and largescale structure have been obtained. In this regard, a fundamental discovery was made, which showed that our Universe is expanding with acceleration. To describe this phenomenon, many models have been created. One of the main directions is the modification of the general theory of relativity, in particular, $F(R)$ gravity, which is a kind of functional dependence on the curvature of space $R$ in a scalar. Within this modification, the evolution of various fields, such as scalar or fermion, have been investigated. Then, I talk a modified $F(R) $model of gravity with a fermion field $f$essence in the quantum approach. The equations of motion of this model are obtained for the homogeneous and isotropic FriedmanRobertsonWalker spacetime. To determine the parameters of the connection of matter and spacetime, we consider the standard model of the accelerated expansion of the de Sitter Universe. [Preview Abstract] 
Saturday, November 2, 2019 9:30AM  9:42AM 
E04.00006: Multipole Hair of SchwarzschildTangherlini Black Holes Matthew Fox We study the field of an electric point charge that is slowly lowered into an $n + 1$ dimensional SchwarzschildTangherlini black hole. We find that if $n > 3$, then countably infinite multipole moments manifest to observers outside the event horizon as the charge falls in. This suggests the final state of the black hole is not characterized by a ReissnerNordstr\"omTangherlini geometry. Instead, for odd $n$, the final state either possesses a degenerate horizon, undergoes a discontinuous topological transformation during the infall of the charge, or both. For even $n$, the final state is not guaranteed to be asymptoticallyflat. [Preview Abstract] 
Saturday, November 2, 2019 9:42AM  9:54AM 
E04.00007: Thermodynamic equivalence of Jordan and Einstein frame in scalartensor theory Krishnakanta Bhattacharya, Bibhas Majhi, Ashmita Das Scalartensor theory is a modified theory of gravity which can be described in the two frames. The original frame is known as the Jordan frame, where a scalar field $\phi$ is nonminimally coupled with the Ricci scalar $R$. This nonminimal coupling of $\phi$ and $R$ can be removed by a conformal transformation of the metric tensor and a rescaling in $\phi$. This conformal frame is known as the Einstein frame. There are two major questions in scalartensor theory: (1) Whether the conformal equivalence of the action in the two frames is merely a mathematical equivalence or whether these two frames are indeed equivalent. (2) What are the explicit covariant expressions of the physical quantities (energy, entropy, temperature) and how they are connected in the two frames. In Phys.Rev.D {\bf 95}, 064026 (2017) and Phys.Rev.D {\bf 97}, 124013 (2018) we have explored these issues. We show that by properly defining the Lagrangians in the two frames, one can obtain the first law and the covariant expressions of the thermodynamic parameters (including energy) following the IyerWald formalism. We also show that all the thermodynamic parameters are conformally invariant. [Preview Abstract] 
Saturday, November 2, 2019 9:54AM  10:06AM 
E04.00008: Derivation of cosmic acceleration and the cosmological constant in the local universe Thomas Chamberlain Observed type Ia supernovae reveal accelerating Hubble expansion indicating an energy fluid fills space or that the excellence of general relativity on the Solar scale is not matched on the cosmic scale. The latter alternative could mean that a deeper understanding of spacetime physics is appropriate for solving ``dark energy'' and related problems (e.g., tension in the Hubble parameter measurements). Here the cosmological constant in general relativity has been recalled as germane to cosmic acceleration, however a satisfactory relativistic explanation has not been given. We consider that postulated inwardinfinite lightspeed along lookback time and distance (replacing Einstein's isotropic lightspeed as \textit{empirically} equivalent) yields an \underline {empirically consequential} outward cosmic time dilation which, when ``rotated'' into epochal space and inserted into the Lorentz transformation, gives a linearly increasing cosmic acceleration consistent with Hubble's law. This \textit{leading order }resultin agreement with supernova type Ia magnitude data in the local universe (z \textless 0.3) and the empirical facts in generaladds to previous knowledge by giving relativistic relationships for cosmic acceleration and the corresponding cosmological constant. Followon investigation accounting for lookback time and distance is anticipated of ``too fast'' cosmicstructure dynamics (e.g., of wide binary stars, spiral galaxies, and galaxy clusters). [Preview Abstract] 
Saturday, November 2, 2019 10:06AM  10:18AM 
E04.00009: Application of Noether symmetry in f(R$_{\mathrm{GHL}})$ Horava  Lifshitz gravity \quad Moldir Arzimbetova, Shynaray Myrzakul We study the Noether symmetry of the general cosmological model using the behavior of the corresponding Lagrangian for infinitesimal generators of the desired symmetry. We explicitly calculate the form of the function f(R$_{\mathrm{GHL}})$ for which such symmetries exist. It is shown that the resulting form f(R$_{\mathrm{GHL}})$ gives an expansion according to a power law for the cosmological scale factor. Horava proposed a theory of quantum gravity, which takes into account the degree of renormalizability in ultraviolet radiation. This was achieved due to anisotropic scaling between space and time, and, therefore, it violates Lorentz invariance in the ultraviolet range. The infrared limit of the theory reproduces the general theory of relativity for a particular choice of parameter, namely $\lambda =$1. Lorentz symmetry breaking is performed by the preferred foliation of threedimensional spatially similar hypersurfaces, which, in turn, divide the coordinate into space and time. This allows us to write down the EinsteinHilbert action with higher spatial derivatives of the metric. This improves the ultraviolet behavior of the graviton propagator and displays a renormalizable theory of power counting. Moreover, the action has only secondorder time derivatives that prevent the presence of ghosts in theory. [Preview Abstract] 
(Author Not Attending)

E04.00010: On the Role of EinsteinCartan Gravity in Fundamental Particle Physics Carl Diether, Joy Christian Two of the major open questions in particle physics are: (1) Why are the elementary fermionic particles that are so far observed have such low massenergy compared to the Planck energy scale? And (2), what mechanical energy may be counterbalancing the divergent electrostatic and strong force energies of pointlike charged fermions in the vicinity of the Planck scale? In this paper, using a hitherto unrecognized mechanism derived from the nonlinear amelioration of Dirac equation known as the HehlDatta equation within EinsteinCartanSciamaKibble extension of general relativity, we present detailed numerical estimates suggesting that the mechanical energy arising from the gravityinduced selfinteraction in the ECSK theory can address both of these questions in tandem. [Preview Abstract] 
Saturday, November 2, 2019 10:30AM  10:42AM 
E04.00011: Minimum length in quantum gravity  modified commutator versus modified operators Jaeyeong Lee, Michael Bishop, Douglas Singleton Quantum gravity suggests that we~should~modify the Heisenberg uncertainty relation to obtain a minimum length scale.~Previously modifying the~commutator was considered sufficient to lead to a minimum length scale. However, we~show~that the modification of the position and momentum operators is~more~crucial~than~the modified commutator when specifying the existence~of the minimum length scale~We do this by using well behaved trial wave functions to examine the modified uncertainty connected with the modified commutator and operators. [Preview Abstract] 
Saturday, November 2, 2019 10:42AM  10:54AM 
E04.00012: Dear Mr. Susskind, The maximum number of microstates in a Planck mass Paul OBrien Professor Leonard Susskind is the greatest living physicist today, IMO. “The Black Hole War” inspired my greatest idea. What if the Mass of a BH was distributed across the Schwarzschild horizon, like an infinitely thin soap bubble? It turns out not to be true, but it made me think about distributing mass on a 2D surface. I found a density function for a 2D surface. The Schwarzschild BH metric is quantized by the Planck length, and thus is 1D. The maximum density is M$_{p}$/2L$_{p}$ measured by radius. At this density, confinement of 2 or more, leads to a larger BH with lower density and temperature. In 2D, the maximum density is double that of 1D. Orthogonality enables encoding 2 orthogonal properties of Mass and Energy with a single quantum, equal to a Planck area. The ability to encode both, gives us thermal density and entropy. Both are density functions. The Holographic density function describes our Universe as a BH with 1DOF but also any number of DOF up to the maximum density allowed. This rule forbids singularities and defines a finite spacetime. The initial condition for our universe is describable as quantum computer in(2+1)D the size of a speck of dust @ max density. Jacob Bekenstein would be proud. [Preview Abstract] 
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