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Listening to echoes has long been a way to estimate distances, a technique whose backbone is the time delay. The gravitational field also creates a time delay, called Shapiro time delay, that helps us extract some information from the field…

General Relativity and Quantum Cosmology · Physics 2024-01-17 A. Ghasemi Azar , H. Rezaei , H. Moradpour

The observation of a pulsar closely orbiting the galactic center supermassive black hole would open the window for an accurate determination of the black hole parameters and for new tests of General Relativity. An important relativistic…

General Relativity and Quantum Cosmology · Physics 2019-03-13 Eva Hackmann , Arnab Dhani

We implement a Markov Chain Monte Carlo method to obtain posterior probability distributions for the parameters of the S2 star orbit around Sagittarius A*, for seven representative non-rotating black hole space-time solutions. In…

High Energy Astrophysical Phenomena · Physics 2026-02-10 César Navarrete , Fernando Vázquez-Chávez , Alejandro Cruz-Osorio , Néstor Ortiz

We present an exact analytical equation for the Shapiro time delay (STD) due to a spherical non-rotating body. As a result, accurate values of the STD in comparison with first and second-order expressions for Schwarzschild spacetime (1Sch…

General Relativity and Quantum Cosmology · Physics 2025-09-16 Oscar del Barco

We calculate the time delay between different relativistic images formed by black hole gravitational lensing in the strong field limit. For spherically symmetric black holes, it turns out that the time delay between the first two images is…

General Relativity and Quantum Cosmology · Physics 2009-11-10 V. Bozza , L. Mancini

The time delay of light as it passes by a massive object, first calculated by Shapiro in 1964, is a hallmark of the curvature of space-time. To date, all measurements of the Shapiro time delay have been made over solar-system distance…

General Relativity and Quantum Cosmology · Physics 2014-11-18 S. Ballmer , S. Márka , P. Shawhan

One avenue for testing the no-hair theorem is obtained through timing a pulsar orbiting close to a black hole and fitting for quadrupolar effects on the time-of-arrival of pulses. If deviations from the Kerr quadrupole are measured, then…

General Relativity and Quantum Cosmology · Physics 2015-11-09 Pierre Christian , Dimitrios Psaltis , Abraham Loeb

A new polymer black hole solution in loop quantum gravity was proposed recently. The difference between the polymer black hole and Schwarzschild black hole is captured by a quantum parameter $A$. In order to get the constraints on parameter…

General Relativity and Quantum Cosmology · Physics 2022-05-02 Yun-Long Liu , Zhao-Qing Feng , Xiang-Dong Zhang

The "Shapiro delay" experienced by an astronomical messenger traveling through a gravitational field has been used to place constraints on possible deviations from the equivalence principle. The standard Shapiro delay used to obtain these…

General Relativity and Quantum Cosmology · Physics 2019-12-05 Olivier Minazzoli , Nathan K. Johnson-McDaniel , Mairi Sakellariadou

We develop the regular black hole solutions recently proposed in arXiv:2109.05974 by incorporating the 1-loop quantum correction to the Newton potential as well as a time delay between an observer at the regular center and that at infinity.…

General Relativity and Quantum Cosmology · Physics 2022-05-03 Yi Ling , Meng-He Wu

The time delay experienced by a light ray as it passes through a changing gravitational potential by a non-zero mass distribution along the line of sight is usually referred to as Shapiro delay. Shapiro delay has been extensively measured…

Astrophysics of Galaxies · Physics 2016-04-28 Shantanu Desai , Emre O. Kahya

In the next decade or two, extremely accurate tests of general relativity under extreme conditions are expected from gravitational wave observations of binary black hole mergers with a wide range of mass ratios. In addition, major…

General Relativity and Quantum Cosmology · Physics 2011-06-14 Neil Ashby , Peter L. Bender

We developed a numerical methodology to compute the fully-relativistic propagation time of photons emitted by a pulsar in orbit around a massive compact object, like the supermassive black hole Sagittarius A* in the Galactic Center, whose…

General Relativity and Quantum Cosmology · Physics 2023-07-20 Riccardo Della Monica , Ivan de Martino , Mariafelicia de Laurentis

Camanho, Edelstein, Maldacena and Zhiboedov have shown that gravitons can experience a negative Shapiro time delay, i.e. a time advance, in Einstein-Gauss-Bonnet theory. They studied gravitons propagating in singular "shock-wave"…

General Relativity and Quantum Cosmology · Physics 2015-11-24 Giuseppe Papallo , Harvey S. Reall

The gravitational time delay of light, also called the Shapiro time delay, is one of the four classical tests of Einstein's theory of general relativity. This article derives the Newtonian version of the Shapiro time delay from Einstein's…

General Relativity and Quantum Cosmology · Physics 2020-01-03 Markus Pössel

The retarded Green function for linear field perturbations of black hole spacetimes is notoriously difficult to calculate. One of the difficulties is due to a Dirac-$\delta$ divergence that the Green function possesses when the two…

General Relativity and Quantum Cosmology · Physics 2019-11-27 Marc Casals , Brien C. Nolan , Adrian C. Ottewill , Barry Wardell

Schwarzschild black hole being thermodynamically unstable, corrections to its entropy due to small thermal fluctuations cannot be computed. However, a thermodynamically stable Schwarzschild solution can be obtained within a cavity of any…

High Energy Physics - Theory · Physics 2014-11-18 M. M. Akbar , Saurya Das

The ``moving puncture'' technique has led to dramatic advancements in the numerical simulations of binary black holes. Hannam et.al. have recently demonstrated that, for suitable gauge conditions commonly employed in moving puncture…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Thomas W. Baumgarte , Stephen G. Naculich

We use the Kruskal time coordinate T to define the initial time. By this way, it naturally divides the stable study into one connected with the two regions: the white-hole-connected region and the black-hole-connected region. The union of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Guihua Tian

The recent discovery of gravitational waves from merging black holes has generated interest in primordial black holes as a possible component of the dark matter. In this paper, we show that pulsar timing may soon have sufficient data to…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Katelin Schutz , Adrian Liu
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