Bulletin of the American Physical Society
APS April Meeting 2021
Volume 66, Number 5
Saturday–Tuesday, April 17–20, 2021; Virtual; Time Zone: Central Daylight Time, USA
Session T16: New perspectives in Gravitational PhysicsLive
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Sponsoring Units: DGRAV Chair: Helvi Witek, Univ of Illinois at Urbana-Champaign |
Monday, April 19, 2021 3:45PM - 3:57PM Live |
T16.00001: Presence of Inertial Induction in General Relativity L.L. Williams The title of our presentation plays on the title of the Brans (1977) paper in PhysRev, "Absence of inertial induction in general relativity." We revisit ideas of inertial induction and Mach's principle in general relativity, including early prescient work by Einstein on inertia in 1921. We find there appear to in fact be effects on local systems from the gravitational field of the universe, just not the ones Brans was considering. Brans's main concern was in regard to the Equivalence Principle, so we address those concerns as well. Since ``inertial induction" is a loosely-defined term, it seems fair to broaden its interpretation slightly to deliver a verdict opposite to that of Brans in 1977. [Preview Abstract] |
Monday, April 19, 2021 3:57PM - 4:09PM Live |
T16.00002: Revised Rotating Metric that generalizes Yilmaz Exponential Metric. James Graber We present an updated and corrected version of a rotating metric that generalizes the Yilmaz Exponential Metric. [Preview Abstract] |
Monday, April 19, 2021 4:09PM - 4:21PM Live |
T16.00003: Geometry near the Inner Horizon of a Rotating, Accreting Black Hole Tyler McMaken, Andrew Hamilton What will an observer see after falling within an astrophysically realistic black hole? Here we present a novel classical model to describe the near-inner horizon geometry of a rotating, accreting black hole. The model assumes spacetime is homogeneous and is sourced by radial streams of a collisionless, null fluid, and it predicts that the standard Poisson-Israel mass inflation phenomenon will be interrupted by a Kasner-like collapse toward a spacelike singularity. By connecting this model to the Kerr metric in a regime where both are valid, we show that an infalling observer will meet their end near the inner horizon after passing through two epochs of spacetime evolution. The simplicity of the model also gives the potential for future calculations of the quantum backreaction to the metric. [Preview Abstract] |
Monday, April 19, 2021 4:21PM - 4:33PM Live |
T16.00004: Physics of prime gas and its connection to blackhole Charli Pal, Subodha Mishra While studying quantum and classical aspects of a system, it is important to know how to treat an abstract prime number system which is nondynamical, as a dynamical one in physics. Here we study the hidden nonlinear dynamics of an interacting quantum many particle system in 1 dimension representing prime numbers after we derive the 2-body interaction potential between particles through Schr\"{o}dinger equation. The density for prime gas representing prime numbers is constructed from the asymptotic form of prime counting function. By taking the quantum mechanics formalism we induce the calculation of gaps through expectation value. In the corresponding classical system, the trajectories and associated fixed points, which are half stable are analysed. The famous Lambert W function arises naturally as a solution of fixed points. The connection between prime number and blackhole appears serendipitously in the solution of fixed points as a simple mathematical identification with different times associated with blackhole. REFERENCES: S. Mishra and C. C Pal, Preprint: DOI:10.13140/RG.2.2.33589.29926 B. Julia, Physica A 203, 425 (1994) H. C. Rosu, Mod. Phys. Lett. A 18, 1205 (2003) [Preview Abstract] |
Monday, April 19, 2021 4:33PM - 4:45PM Live |
T16.00005: A Generalized Unified Electro-Gravity Theory for the Proton, and Related Composite Particles Nirod Das A new Unified Electro-Gravity (UEG) theory was recently proposed and presented in the APS April-2020 Meeting, which self-consistently models the complete stable structure of a spinning electron. The UEG theory is as well applicable to model rotation in spiral galaxies, without any hypothetical dark matter, providing independent support to the theory in the astrophysical domain. In its basic form, the theory introduces a modified gravitational field proportional to the energy density surrounding the charge, with the constant of proportionality referred to as the UEG constant. The theory is now generalized by allowing the ‘‘UEG constant’’ to be a function of increasing energy density, allowing stable structures of an elementary charge with increasing levels of mass/energy. The stable elementary charge particle, which is equivalent to the electron but with the next higher level of mass/energy, is recognized to be the proton. The generalized UEG theory would explain the physical origin of proton’s g-factor, and the measured radius of proton in close relation to the classical radius of electron. The theory would also lead to recognizing neutron, muon and pion as possible composite particles, built upon the basic structure of proton, but with additional surrounding charged layers. [Preview Abstract] |
Monday, April 19, 2021 4:45PM - 4:57PM Live |
T16.00006: Intrinsic vacuum motions and the GR -- spin-\textonehalf connection Ronald Bruner When the vacuum is assumed to have uniform non-zero energy density, and the spatial coordinates are time-dependent, general relativity describes intrinsic motions, relative to a stationary observer, that depend on the sign of the vacuum energy density. For example, intrinsic motions associated with a positive energy density vacuum (or a positive cosmological constant) are the well-known outward-accelerating motions of the cosmic expansion. We find that the intrinsic vacuum motions associated with a negative energy density vacuum are circular in spacetime, and can be interpreted as describing the intrinsic motions of spin-\textonehalf particles. When the angular frequency of these motions is equated to the angular frequency of the quantum of mass of the negative energy density vacuum field these results imply a clear connection between general relativity and quantum theory at the Planck length scale. [Preview Abstract] |
Monday, April 19, 2021 4:57PM - 5:09PM Live |
T16.00007: Hidden symmetries for transparent de Sitter space Ian Morrison It is known that odd-dimensional de Sitter space acts as a transparent potential for free fields. Previous studies have explained this phenomena by relating de Sitter free field equations of motion to the time-independent Schrödinger equation with known transparent potentials. In this work we show that de Sitter’s transparency is a consequence of an infinite set of ‘hidden’ symmetries. These symmetries arise from an accidental symmetry for the zero-mode of matter fields, as well as the boost isometry of de Sitter space. For simplicity, we consider the case of massive Klein–Gordon theory. We show that the Noether charges associated with these hidden symmetries distinguish the two linearly-independent solutions of the free field wave equation in the asymptotic past and future of de Sitter. Conservation of these charges requires that the asymptotic behavior of any solution be identical, up to a constant phase, in the future and the past, which is the property of transparency. In the quantized theory, these charges act trivially on particle states belonging to the in/out vacuum Fock space. For particle states constructed from other vacua, the action of the charges generates particles. [Preview Abstract] |
Monday, April 19, 2021 5:09PM - 5:21PM Live |
T16.00008: Compensator fields in dimensional reduction and compactification without truncation --- Part II: Yang-Mills theory Michael Schulz In dimensionally reduced theories with gauge (or diffeomorphism) invariance, consistency of the Kaluza-Klein ansatz requires the introduction of compensator fields. The compensator fields project gauge-variant field fluctuations to their horizontal components, which in turn determine the gauge-invariant moduli space metric that appears in kinetic terms of the lower dimensional theory. The compensator fields must be introduced "by hand" in dimensional reduction (i.e., compactification truncated to zero modes), but arise automatically in the full untruncated theory. Warming up with U(1) gauge theory, and then focusing on Yang-Mills theory compactified on an arbitrary compact manifold, we re-express the full untruncated parent theory in lower dimensional language, and identify the compensator fields. One of their known geometric interpretations features prominently. The moduli space of gauge fields (or metrics) on the compact manifold can be regarded as a principal bundle whose fiber is the space of gauge transformations. The compensator fields arise as a repackaging of the connection on this bundle. [Preview Abstract] |
Monday, April 19, 2021 5:21PM - 5:33PM On Demand |
T16.00009: Space-Time and Quantum Mechanics Implications of Discovered Cosmic Acceleration Thomas Chamberlain Although cosmology is ``a branch of astronomy dealing with origin, evolution, and eventual fate of the universe,'' it is the physics frontier on atomic and laboratory scales as well. Einstein's relativity is a principal contributor to the overarching LambdaCDM model from the Big Bang to present time. Now empirical constraints and discoveries ranging from observed wide-binary/spiral galaxy rotation flattening to cosmic acceleration and the Hubble tension point to extended space-time physics encompassing (again) all scales. Here we build on derived cosmic acceleration (2019/20) and the related derivation of wide-binary/spiral galaxy rotation flattening (2017/20; setting aside ``external field effect'' for now) to show that the ``round-trip axiom'' holds in the accelerating Hubble-expansion (as it holds in Michelson-Morley type experiments). This step is a further validation of ``inward-singular light-speed'' to each point (with half-c outward) that introduces novel time-dilation/gravitational fields while accommodating conventional mathematical physics. Additional results bearing on quantum mechanics' temporal entanglement and the long-standing measurement problem are addressed. [Preview Abstract] |
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