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Physical Sciences and Mathematics *Commons*^{™}

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Articles **1** - **10** of ** 10**

## Full-Text Articles in Physical Sciences and Mathematics

Gravity's Light In The Shadow Of The Moon, Andri Gretarsson, Preston Jones, Douglas Singleton

#### Gravity's Light In The Shadow Of The Moon, Andri Gretarsson, Preston Jones, Douglas Singleton

*Publications*

In this essay we look at the possibility of vacuum production of very low frequency electromagnetic radiation from a gravitational wave background (i.e. gravity's light). We also propose that this counterpart electromagnetic radiation should be detectable by a lunar orbiting satellite which is periodically occulted by the Moon (i.e., in the shadow of the Moon). For concreteness we consider the possibility of detection of both the gravitational wave and hypothesized electromagnetic radiation counterpart from the supernova core collapse of Betelgeuse

Relating Noncommutative So(2,3)* Gravity To The Lorentz-Violating Standard-Model Extension, Quentin G. Bailey, Charles D. Lane

#### Relating Noncommutative So(2,3)* Gravity To The Lorentz-Violating Standard-Model Extension, Quentin G. Bailey, Charles D. Lane

*Publications*

We consider a model of noncommutative gravity that is based on a spacetime with broken local SO(2,3)* symmetry. We show that the torsion-free version of this model is contained within the framework of the Lorentz-violating Standard-Model Extension (SME). We analyze in detail the relation between the torsion-free, quadratic limits of the broken SO(2,3)* model and the Standard-Model Extension. As part of the analysis, we construct the relevant geometric quantities to quadratic order in the metric perturbation around a flat background.

Gw170817: Implications For The Stochastic Gravitational-Wave Background From Compact Binary Coalescences, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, E. M. Gretarsson, B. Hughey, M. Muratore, J. W. W. Pratt, S. G. Schwalbe, K. Staats, M. J. Szczepańczyk, M. Zanolin, Et Al.

#### Gw170817: Implications For The Stochastic Gravitational-Wave Background From Compact Binary Coalescences, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, E. M. Gretarsson, B. Hughey, M. Muratore, J. W. W. Pratt, S. G. Schwalbe, K. Staats, M. J. Szczepańczyk, M. Zanolin, Et Al.

*Publications*

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude ΩGW(f=25 ...

A Gravitational-Wave Standard Siren Measurement Of The Hubble Constant, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, E. M. Gretarrson, B. Hughey, M. Muratore, J. W. W. Pratt, S. G. Schwalde, K. Staats, M. J. Szczepańczyk, M. Zanolin, Et Al.

#### A Gravitational-Wave Standard Siren Measurement Of The Hubble Constant, B. P. Abbott, K. Aultoneal, S. Gaudio, K. Gill, E. M. Gretarrson, B. Hughey, M. Muratore, J. W. W. Pratt, S. G. Schwalde, K. Staats, M. J. Szczepańczyk, M. Zanolin, Et Al.

*Publications*

The detection of GW170817 (Abbott et al. 2017a) in both gravitational waves and electromagnetic waves heralds the age of gravitational-wave multi-messenger astronomy. On 17 August 2017 the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) (LIGO Scientific Collaboration et al. 2015) and Virgo (Acernese et al. 2015) detectors observed GW170817, a strong signal from the merger of a binary neutron-star system. Less than 2 seconds after the merger, a gamma-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO-Virgo-derived location of the gravitational-wave source (Abbott et al. 2017b; Goldstein et al. 2017; Savchenko et al. 2017 ...

Constraints On Sme Coefficients From Lunar Laser Ranging, Very Long Baseline Interferometry, And Asteroid Orbital Dynamics, C. Le Poncin-Lafitte, A. Bourgoin, A. Hees, S. Bouquillon, S. Lambert, Q. G. Bailey, Et Al.

#### Constraints On Sme Coefficients From Lunar Laser Ranging, Very Long Baseline Interferometry, And Asteroid Orbital Dynamics, C. Le Poncin-Lafitte, A. Bourgoin, A. Hees, S. Bouquillon, S. Lambert, Q. G. Bailey, Et Al.

*Publications*

Lorentz symmetry violations can be parametrized by an effective field theory framework that contains both General Relativity and the Standard Model of particle physics, called the Standard-Model Extension or SME. We consider in this work only the pure gravitational sector of the minimal SME. We present new constraints on the SME coefficients obtained from lunar laser ranging, very long baseline interferometry, and planetary motions.

Gravity Sector Of The Sme, Q. G. Bailey

#### Gravity Sector Of The Sme, Q. G. Bailey

*Publications*

In this talk, the gravity sector of the effective field theory description of local Lorentz violation is discussed, including minimal and nonminimal curvature couplings. Also, recent experimental and observational analyses including solar-system ephemeris and short-range gravity tests are reviewed.

What Do We Know About Lorentz Symmetry?, Q. G. Bailey

#### What Do We Know About Lorentz Symmetry?, Q. G. Bailey

*Publications*

Precision tests of Lorentz symmetry have become increasingly of interest to the broader gravitational and high-energy physics communities. In this talk, recent work on violations of local Lorentz invariance in gravity is discussed, including recent analysis constraining Lorentz violation in a variety of gravitational tests. The arena of short-range tests of gravity is highlighted, demonstrating that such tests are sensitive to a broad class of unexplored signals that depend on sidereal time and the geometry of the experiment.

The Equivalence Principle, Uniformly Accelerated Reference Frames, And The Uniform Gravitational Field, Gerardo Muñoz, Preston Jones

#### The Equivalence Principle, Uniformly Accelerated Reference Frames, And The Uniform Gravitational Field, Gerardo Muñoz, Preston Jones

*Publications*

The relation between uniformly accelerated reference frames in flat spacetime and the uniform gravitational field is examined in a relativistic context. It is shown that contrary to previous statements, equivalence does not break down in this context. No restrictions to Newtonian approximations or small enclosures are necessary.

Electromagnetic Radiation From Temporal Variations In Space-Time And Progenitors Of Gamma Ray Burst And Millisecond Pulsars, Preston Jones

#### Electromagnetic Radiation From Temporal Variations In Space-Time And Progenitors Of Gamma Ray Burst And Millisecond Pulsars, Preston Jones

*Publications*

A time varying space–time metric is shown to be a source of electromagnetic radiation even in the absence of charge sources. The post-Newtonian approximation is used as a realistic model of the connection between the space–time metric and a time-varying gravitational potential. Rapid temporal variations in the metric from the coalescence of relativistic stars are shown to be likely progenitors of gamma ray burst and millisecond pulsars.

A Dyad Theory Of Hydrodynamics And Electrodynamics, Preston Jones

#### A Dyad Theory Of Hydrodynamics And Electrodynamics, Preston Jones

*Publications*

The dyadic calculus is developed in a form suitable for the description of physical relations in curved space. The 4-space equations of hydrodynamics and electrodynamics are constructed using this dyadic calculus. As a demonstration of the relationship between gravity and electrodynamics a time varying metric is shown to generate electromagnetic radiation.