New Experiments in Gravitational Physics
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Relativity and Fundamental Physics
Relativity and Fundamental Physics Sergei Kopeikin (1,2,*) 1) Dept. of Physics and Astronomy, University of Missouri, 322 Physics Building., Columbia, MO 65211, USA 2) Siberian State University of Geosystems and Technology, Plakhotny Street 10, Novosibirsk 630108, Russia Abstract Laser ranging has had a long and significant role in testing general relativity and it continues to make advance in this field. It is important to understand the relation of the laser ranging to other branches of fundamental gravitational physics and their mutual interaction. The talk overviews the basic theoretical principles underlying experimental tests of general relativity and the recent major achievements in this field. Introduction Modern theory of fundamental interactions relies heavily upon two strong pillars both created by Albert Einstein – special and general theory of relativity. Special relativity is a cornerstone of elementary particle physics and the quantum field theory while general relativity is a metric- based theory of gravitational field. Understanding the nature of the fundamental physical interactions and their hierarchic structure is the ultimate goal of theoretical and experimental physics. Among the four known fundamental interactions the most important but least understood is the gravitational interaction due to its weakness in the solar system – a primary experimental laboratory of gravitational physicists for several hundred years. Nowadays, general relativity is a canonical theory of gravity used by astrophysicists to study the black holes and astrophysical phenomena in the early universe. General relativity is a beautiful theoretical achievement but it is only a classic approximation to deeper fundamental nature of gravity. Any possible deviation from general relativity can be a clue to new physics (Turyshev, 2015). -
What Is Gravity Probe B?
What is Gravity Probe B? Gravity Probe B (GP-B) is a NASA physics mission to experimentally in• William Fairbank once remarked: “No mission could be sim• vestigate Einstein’s 1916 general theory of relativity—his theory of gravity. pler than Gravity Probe B. It’s just a star, a telescope, and a spin• GB-B uses four spherical gyroscopes and a telescope, housed in a satellite ning sphere.” However, it took the exceptional collaboration of Stan• orbiting 642 km (400 mi) above the Earth, to measure, with unprecedented ford, MSFC, Lockheed Martin and a host of others more than four accuracy, two extraordinary effects predicted by the general theory of rela• decades to develop the ultra-precise gyroscopes and the other cut• tivity: 1) the geodetic effect—the amount by which the Earth warps the local ting-edge technologies necessary to carry out this “simple” experiment. spacetime in which it resides; and 2) the frame-dragging effect—the amount by which the rotating Earth drags its local spacetime around with it. GP-B tests these two effects by precisely measuring the precession (displacement) The GP-B Flight Mission angles of the spin axes of the four gyros over the course of a year and com• paring these experimental results with predictions from Einstein’s theory. On April 20, 2004 at 9:57:24 AM PDT, a crowd of over 2,000 current and former GP-B team members and supporters watched and cheered as the A Quest for Experimental Truth GP-B spacecraftlift ed offf rom Vandenberg Air Force Base. -
Chapter 1 Introduction
Chapter 1 Introduction 1.1 Introduction Einsteins theory of general relativity (GR) [Einstein, 1915b,a, de Sitter, 1917, Silberstein, 1917] together with quantum field theory are considered to be the pillars of modern physics. GR deals with gravitational phenomena treating space-time as a four-dimensional manifold. The theory has a well understood and mathematically very elegant structure and is internally consistent. GR describes gracefully all the experimental tests of gravity [Weinberg, 1972, Berti et al., 2015] conducted till now without a single adjustable parameter. 1.2 General Relativity The inverse-square gravitational force law introduced by Newton predicted cor- rectly a variety of gravitational phenomena including planetary motion. In fact the 10 Chapter 1: Introduction 11 Newtons theory was very successful in describing all the known gravitational phe- nomena at that time. The first deviation from the Newtons theory was noticed in the precession of Mercurys orbit; a 43 arc-seconds per century excess precession over that given by Newtons theory was observed. However, not because of such small deviation in just one experimental results, Einstein developed General relativity to make the theory of gravitation consistent with Special Theory of Relativity (STR). Newtonian mechanics is based on the existence of absolute space and thereby absolute motion whereas STR rests on the idea that all (un-accelerated) motions are relative in nature. A consequent feature emerges in STR that no information can be transmitted with speed greater than the speed of light whereas the Newtons law of gravity implies action at a distance i.e. in Newtonian paradigm the gravita- tional information moves with infinite speed. -
Partículas De Prueba Con Espín En Experimentos Tipo Michelson Y Morley
Partículas de prueba con espín en experimentos tipo Michelson y Morley A Dissertation Presented to the Faculty of Science of Universidad Nacional de Colombia in Candidacy for the Degree of Doctor of Philosophy by Nelson Velandia-Heredia, S.J. Dissertation Director: Juan Manuel Tejeiro, Dr. Rer. Nat. November 2017 Abstract Partículas de prueba con espín en experimentos tipo Michelson y Morley Nelson Velandia-Heredia, S.J. 2018 Resumen En esta tesis, nosotros caracterizamos, con ayuda de la relatividad numérica, los efectos gravitomagnéticos para partículas de prueba con espín cuando se mueven en un campo rotante. Dado este propósito, nosotros resolveremos numéricamente las ecuaciones de Mathisson-Papapetrou- Dixon en una métrica de Kerr. Además, estu- diaremos la influencia del valor y la orientación de espín en el efecto reloj. Palabras clave: Relatividad general, relatividad numérica, ecuaciones de Mathisson-Papapetrou-Dixon, métrica de Kerr, partículas de prueba con es- pín. Abstract In this thesis, we characterize, with help of the numerical relativity, the gravito- magnetic effects for spinning test particles when are moving in a rotating field. Since this aim, we numerically solve the Mathisson-Papapetrou-Dixon equations in a Kerr metric. Also, we study the influence of value and orientation of the spin in the clock effect. Keywords: General relativity, numerical relativity, Mathisson-Papapetrou-Dixon equations, Kerr metric, the spinning test particles ii Copyright c 2018 by Nelson Velandia-Heredia, S.J. All rights reserved. i Contents 1 Introduction 1 2 Formulation for the equations of motion 8 2.1 Introduction................................8 2.2 Equation of linear field . 10 2.2.1 Newtonian mechanics . -
+ Gravity Probe B
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Gravity Probe B Experiment “Testing Einstein’s Universe” Press Kit April 2004 2- Media Contacts Donald Savage Policy/Program Management 202/358-1547 Headquarters [email protected] Washington, D.C. Steve Roy Program Management/Science 256/544-6535 Marshall Space Flight Center steve.roy @msfc.nasa.gov Huntsville, AL Bob Kahn Science/Technology & Mission 650/723-2540 Stanford University Operations [email protected] Stanford, CA Tom Langenstein Science/Technology & Mission 650/725-4108 Stanford University Operations [email protected] Stanford, CA Buddy Nelson Space Vehicle & Payload 510/797-0349 Lockheed Martin [email protected] Palo Alto, CA George Diller Launch Operations 321/867-2468 Kennedy Space Center [email protected] Cape Canaveral, FL Contents GENERAL RELEASE & MEDIA SERVICES INFORMATION .............................5 GRAVITY PROBE B IN A NUTSHELL ................................................................9 GENERAL RELATIVITY — A BRIEF INTRODUCTION ....................................17 THE GP-B EXPERIMENT ..................................................................................27 THE SPACE VEHICLE.......................................................................................31 THE MISSION.....................................................................................................39 THE AMAZING TECHNOLOGY OF GP-B.........................................................49 SEVEN NEAR ZEROES.....................................................................................58 -
Space, Time, and Spacetime
Fundamental Theories of Physics 167 Space, Time, and Spacetime Physical and Philosophical Implications of Minkowski's Unification of Space and Time Bearbeitet von Vesselin Petkov 1. Auflage 2010. Buch. xii, 314 S. Hardcover ISBN 978 3 642 13537 8 Format (B x L): 15,5 x 23,5 cm Gewicht: 714 g Weitere Fachgebiete > Physik, Astronomie > Quantenphysik > Relativität, Gravitation Zu Inhaltsverzeichnis schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, eBooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte. The Experimental Verdict on Spacetime from Gravity Probe B James Overduin Abstract Concepts of space and time have been closely connected with matter since the time of the ancient Greeks. The history of these ideas is briefly reviewed, focusing on the debate between “absolute” and “relational” views of space and time and their influence on Einstein’s theory of general relativity, as formulated in the language of four-dimensional spacetime by Minkowski in 1908. After a brief detour through Minkowski’s modern-day legacy in higher dimensions, an overview is given of the current experimental status of general relativity. Gravity Probe B is the first test of this theory to focus on spin, and the first to produce direct and unambiguous detections of the geodetic effect (warped spacetime tugs on a spin- ning gyroscope) and the frame-dragging effect (the spinning earth pulls spacetime around with it). -
Static Spherically Symmetric Black Holes in Weak F(T)-Gravity
universe Article Static Spherically Symmetric Black Holes in Weak f (T)-Gravity Christian Pfeifer 1,*,† and Sebastian Schuster 2,† 1 Center of Applied Space Technology and Microgravity—ZARM, University of Bremen, Am Fallturm 2, 28359 Bremen, Germany 2 Ústav Teoretické Fyziky, Matematicko-Fyzikální Fakulta, Univerzita Karlova, V Holešoviˇckách2, 180 00 Praha 8, Czech Republic; [email protected] * Correspondence: [email protected] † These authors contributed equally to this work. Abstract: With the advent of gravitational wave astronomy and first pictures of the “shadow” of the central black hole of our milky way, theoretical analyses of black holes (and compact objects mimicking them sufficiently closely) have become more important than ever. The near future promises more and more detailed information about the observable black holes and black hole candidates. This information could lead to important advances on constraints on or evidence for modifications of general relativity. More precisely, we are studying the influence of weak teleparallel perturbations on general relativistic vacuum spacetime geometries in spherical symmetry. We find the most general family of spherically symmetric, static vacuum solutions of the theory, which are candidates for describing teleparallel black holes which emerge as perturbations to the Schwarzschild black hole. We compare our findings to results on black hole or static, spherically symmetric solutions in teleparallel gravity discussed in the literature, by comparing the predictions for classical observables such as the photon sphere, the perihelion shift, the light deflection, and the Shapiro delay. On the basis of these observables, we demonstrate that among the solutions we found, there exist spacetime geometries that lead to much weaker bounds on teleparallel gravity than those found earlier. -
Radio and High-Energy Emission of Pulsars Revealed by General Relativity Q
A&A 639, A75 (2020) Astronomy https://doi.org/10.1051/0004-6361/202037979 & c Q. Giraud and J. Pétri 2020 Astrophysics Radio and high-energy emission of pulsars revealed by general relativity Q. Giraud and J. Pétri Université de Strasbourg, CNRS, Observatoire Astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France e-mail: [email protected] Received 18 March 2020 / Accepted 14 May 2020 ABSTRACT Context. According to current pulsar emission models, photons are produced within their magnetosphere and current sheet, along their separatrix, which is located inside and outside the light cylinder. Radio emission is favoured in the vicinity of the polar caps, whereas the high-energy counterpart is presumably enhanced in regions around the light cylinder, whether this is the magnetosphere and/or the wind. However, the gravitational effect on their light curves and spectral properties has only been sparsely researched. Aims. We present a method for simulating the influence that the gravitational field of the neutron star has on its emission properties according to the solution of a rotating dipole evolving in a slowly rotating neutron star metric described by general relativity. Methods. We numerically computed photon trajectories assuming a background Schwarzschild metric, applying our method to neu- tron star radiation mechanisms such as thermal emission from hot spots and non-thermal magnetospheric emission by curvature radiation. We detail the general-relativistic effects onto observations made by a distant observer. Results. Sky maps are computed using the vacuum electromagnetic field of a general-relativistic rotating dipole, extending previous works obtained for the Deutsch solution. We compare Newtonian results to their general-relativistic counterpart. -
The Confrontation Between General Relativity and Experiment
The Confrontation between General Relativity and Experiment Clifford M. Will Department of Physics University of Florida Gainesville FL 32611, U.S.A. email: [email protected]fl.edu http://www.phys.ufl.edu/~cmw/ Abstract The status of experimental tests of general relativity and of theoretical frameworks for analyzing them are reviewed and updated. Einstein’s equivalence principle (EEP) is well supported by experiments such as the E¨otv¨os experiment, tests of local Lorentz invariance and clock experiments. Ongoing tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, the Nordtvedt effect in lunar motion, and frame-dragging. Gravitational wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse–Taylor binary pulsar, and a growing family of other binary pulsar systems is yielding new tests, especially of strong-field effects. Current and future tests of relativity will center on strong gravity and gravitational waves. arXiv:1403.7377v1 [gr-qc] 28 Mar 2014 1 Contents 1 Introduction 3 2 Tests of the Foundations of Gravitation Theory 6 2.1 The Einstein equivalence principle . .. 6 2.1.1 Tests of the weak equivalence principle . .. 7 2.1.2 Tests of local Lorentz invariance . .. 9 2.1.3 Tests of local position invariance . 12 2.2 TheoreticalframeworksforanalyzingEEP. ....... 16 2.2.1 Schiff’sconjecture ................................ 16 2.2.2 The THǫµ formalism ............................. -
Special and General Relativity (PHZ 4601/5606 – Fall 2018) Prof. Bernd A. Berg Phones: 850-273-0001, 850-644-6246, E-Mail: Bberg at Fsu Dot Edu Office: 615 Keen
Special and General Relativity (PHZ 4601/5606 { Fall 2018) Prof. Bernd A. Berg Phones: 850-273-0001, 850-644-6246, e-mail: bberg at fsu dot edu Office: 615 Keen • Class: MWF 9:05{9:55 am at HCB 0209. First Class August 27. • Office hours: Wednesdays 10:30-11:45 am and Thursdays 1:45-3:15 pm, and by ap- pointment (send e-mail). • Grader: Juan Mejia Marin, e-mail jjm17c at my dot fsu dot edu, Office hours Thursdays 5:15{7 pm at 614 Keen, and by appointment (send e-mail). • Midterm: Wednesday, October 17, 2018. • Test on Homework (tentative): Friday November 30. • Final: Thursday, December 11, 10 am { 12 pm at HCB 0209. Required Text: Wolfgang Rindler, Relativity, Special, General and Cosmological, Second Edition, Oxford University Press, New York, 2006. Overview and Goal The course gives an introduction to the fundamentals of space, time and matter. As a systematic, mathematically rigorous treatment is beyond the scope of an undergraduate course, we intend in essence to learn by explaining (often omitting proofs) sections from the textbook by Rindler. Bring the book to the lectures! Under the title Essential Relativity the book started off as a one semester course for senior undergraduate students, but has since then been expanded to a two semester course. Therefore, we will have to omit about half of the material. For an overview see the tentative schedule at the end of this syllabus and compare it with the preface and the table of contents of the textbook. After this course students should be able to explain the fundamental ideas of Special Relativity (SR) and General Relativity (GR) and master to solve by themselves standard problems to which the methods apply. -
Pos(GMC8)062 ∗ [email protected] Speaker
Gravitational lensing along multiple light paths as a PoS(GMC8)062 probe of physics beyond Einstein gravity Hideki Asada∗ Faculty of Science and Technology, Hirosaki University, Hirosaki 036-8561, Japan E-mail: [email protected] The light propagation is reexamined, allowing for various models of modied gravity. We clarify the dependence of the time delay (and induced frequency shift) on modied gravity models and investigate how to distinguish those models, when light propagates in static spherically symmetric spacetimes parameterized to express modied gravity. Implications to gravitational lensing are mentioned. The Manchester Microlensing Conference: The 12th International Conference and ANGLES Microlensing Workshop January 21-25 2008 Manchester, UK ∗Speaker. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/ Gravitational lensing by modied gravity Hideki Asada 1. Introduction A certain modication, in whatever form, in the standard cosmological model, is strongly suggested by recent observations such as the magnitude-redshift relation of type Ia supernovae (SNIa) and the cosmic microwave background (CMB) anisotropy by WMAP. We are forced to add a new component into the energy-momentum tensor in the Einstein equation or modify the theory of general relativity itself. Indeed, plenty of models have been proposed, such as scalar tensor theories, string theories, higher dimensional scenarios and quantum gravity. Therefore, it is of great importance to observationally test these models. PoS(GMC8)062 The theory of general relativity has passed classical tests, such as the deection of light, the perihelion shift of Mercury and the Shapiro time delay, and also a systematic test using the remarkable binary pulsar PSR 1913+16. -
Pulse Arrival-Times from Binary Pulsars with Rotating Black Hole Companions
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Submitted Ap. J. Lett. Pulse Arrival-Times from Binary Pulsars with Rotating Black Hole Companions Pablo Laguna1 and Alex Wolszczan2 Department of Astronomy & Astrophysics and Center for Gravitational Physics & Geometry Penn State University, University Park, PA 16802 ABSTRACT We present a study of the gravitational time delay of arrival of signals from binary pulsar systems with rotating black hole companions. In particular, we investigate the strength of this effect (Shapiro delay) as a function of the inclination, eccentricity and period of the orbit, as well as the mass and angular momentum of the black hole. This study is based on direct numerical integration of null geodesics in a Kerr background geometry. We find that, for binaries with sufficiently high orbital inclinations (> 89o) and compact companion masses > 10M , the effect arising from the rotation of the black hole in the system amounts to a microsecond–level variation of the arrival times of the pulsar pulses. If measurable, this variation could provide a unique signature for the presence of a rotating black hole in a binary pulsar system. Subject headings: pulsars: binaries, relativity Binary pulsars are excellent laboratories for testing General Relativity (GR) and other theories of gravity. Long-term timing observations of relativistic binaries, such as PSR B1913+16 (Hulse & Taylor 1975), yield highly precise measurements of post-Keplerian orbital parameters of the pulsar. In particular, observations of the the orbital decay of PSR B1913+16 induced by gravitational radiative effects have verified the validity of GR to within 0.5% (Taylor & Weisberg 1989).