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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Gravitational Effects In G -Factor Measurements And High-Precision Spectroscopy: Limits Of Einstein's Equivalence Principle, Ulrich D. Jentschura
Gravitational Effects In G -Factor Measurements And High-Precision Spectroscopy: Limits Of Einstein's Equivalence Principle, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
We study the interplay of general relativity, the equivalence principle, and high-precision experiments involving atomic transitions and g-factor measurements. In particular, we derive a generalized Dirac Hamiltonian, which describes both the gravitational coupling for weak fields and the electromagnetic coupling, e.g., to a central Coulomb field. An approximate form of this Hamiltonian is used to derive the leading gravitational corrections to transition frequencies and g factors. The position dependence of atomic transitions is shown to be compatible with the equivalence principle, up to a very good approximation. The compatibility of g-factor measurements requires a deeper subtle analysis in order to …
Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find …
A Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration
A Search For Tensor, Vector, And Scalar Polarizations In The Stochastic Gravitational-Wave Background, Tiffany Summerscales, Ligo Scientific Collaboration And The Virgo Collaboration
Faculty Publications
The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually-unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically-polarized gravitational waves. We find no evidence …
Gravitational Radiation From A Toroidal Source, Aidan Schumann
Gravitational Radiation From A Toroidal Source, Aidan Schumann
Summer Research
This research uses a linearized form of Einstein's General Relativity to find the quadrupole moment from an oscillating toroidal mass and charge current. With the quadrupole terms, we found the gravitational radiation from the energy distribution. We make the assumptions that we are in the low-energy and far field limits.
First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …
Geodesic Structure In Schwarzschild Geometry With Extensions In Higher Dimensional Spacetimes, Ian M. Newsome
Geodesic Structure In Schwarzschild Geometry With Extensions In Higher Dimensional Spacetimes, Ian M. Newsome
Theses and Dissertations
From Birkoff's theorem, the geometry in four spacetime dimensions outside a spherically symmetric and static, gravitating source must be given by the Schwarzschild metric. This metric therefore satisfies the Einstein vacuum equations. If the mass which gives rise to the Schwarzschild spacetime geometry is concentrated within a radius of r=2M, a black hole will form. Non-accelerating particles (freely falling) traveling through this geometry will do so along parametrized curves called geodesics, which are curved space generalizations of straight paths. These geodesics can be found by solving the geodesic equation. In this thesis, the geodesic structure in the Schwarzschild geometry …