scholarly journals Testing pseudo‐complex general relativity with gravitational waves

2018 ◽  
Vol 339 (4) ◽  
pp. 298-305 ◽  
Author(s):  
A. B. Nielsen ◽  
O. Birnholz
Author(s):  
David M. Wittman

General relativity explains much more than the spacetime around static spherical masses.We briefly assess general relativity in the larger context of physical theories, then explore various general relativistic effects that have no Newtonian analog. First, source massmotion gives rise to gravitomagnetic effects on test particles.These effects also depend on the velocity of the test particle, which has substantial implications for orbits around black holes to be further explored in Chapter 20. Second, any changes in the sourcemass ripple outward as gravitational waves, and we tell the century‐long story from the prediction of gravitational waves to their first direct detection in 2015. Third, the deflection of light by galaxies and clusters of galaxies allows us to map the amount and distribution of mass in the universe in astonishing detail. Finally, general relativity enables modeling the universe as a whole, and we explore the resulting Big Bang cosmology.


2014 ◽  
Vol 442 (1) ◽  
pp. 121-130 ◽  
Author(s):  
T. Schönenbach ◽  
G. Caspar ◽  
P. O. Hess ◽  
T. Boller ◽  
A. Müller ◽  
...  

2021 ◽  
Author(s):  
James B. Hartle

Einstein's theory of general relativity is a cornerstone of modern physics. It also touches upon a wealth of topics that students find fascinating – black holes, warped spacetime, gravitational waves, and cosmology. Now reissued by Cambridge University Press, this ground-breaking text helped to bring general relativity into the undergraduate curriculum, making it accessible to virtually all physics majors. One of the pioneers of the 'physics-first' approach to the subject, renowned relativist James B. Hartle, recognized that there is typically not enough time in a short introductory course for the traditional, mathematics-first, approach. In this text, he provides a fluent and accessible physics-first introduction to general relativity that begins with the essential physical applications and uses a minimum of new mathematics. This market-leading text is ideal for a one-semester course for undergraduates, with only introductory mechanics as a prerequisite.


2018 ◽  
Vol 27 (14) ◽  
pp. 1830009
Author(s):  
Virginia Trimble

A large majority of the physics and astronomy communities are now sure that gravitational waves exist, can be looked for, and can be studied via their effects on laboratory apparatus as well as on astronomical objects. So far, everything found out has agreed with the predictions of general relativity, but hopes are high for new information about the universe and its contents and perhaps for hints of a better theory of gravity than general relativity (which even Einstein expected to come eventually). This is one version of the story, from 1905 to the present, told from an unusual point of view, because the author was, for 28.5 years, married to Joseph Weber, who built the first detectors starting in the early 1960s and operated one or more until his death on 30 September 2000.


Author(s):  
Brian Bramson

In linearized, Einstein–Maxwell theory on flat spacetime, an oscillating electric dipole is the source of a spin-2 field. Within this approximation to general relativity, it is shown that electromagnetic waves harbour gravitational waves.


Author(s):  
Mike Goldsmith

In 1916, Einstein published his theory of general relativity, which incorporated fundamentally new ideas about the nature of gravity, including that gravitational effects take time to travel. He also showed that under some circumstances, objects lose energy by emitting ‘ripples’ in time and space: gravitational waves. ‘Gravitational waves’ explains how these waves are very weak and only the most powerful events in the Universe generate strong enough versions to be detected. Gravitational waves differ from other kinds of waves as their only effect is to cause objects to move together and then apart again. They provide a unique new window on the Universe, allowing us to look deeper and further than ever before.


2021 ◽  
pp. 11-35
Author(s):  
Gianfranco Bertone

Before delving into gravitational waves, I illustrate, with nine short stories, the fascinating history of gravity, shedding light on the actual lives and contributions of leading scientists and astronomers, from Tycho Brahe’s adventurous life and grotesque death, to Johannes Kepler’s intuitions and passionate prose. And from Newton’s resolution to cut the Gordian knot of the origin of gravity with his theory of universal gravitation, to Einstein’s heroic struggle to derive the equations of general relativity. Gravity is the weakest of the fundamental forces in nature, yet it subjugates us from the moment we are born. After nine months floating in the womb, suspended in the enveloping heat of the amniotic fluid, we are suddenly confronted with the gravitational pull of our planet. Gravity thus manifests itself as weight, and forces our helpless bodies to the ground, establishing a universal and defining aspect of the human condition.


2020 ◽  
Vol 29 (10) ◽  
pp. 2050072
Author(s):  
Tomohiro Inagaki ◽  
Masahiko Taniguchi

We study the gravitational waves (GWs) in modified Gauss–Bonnet gravity. Applying the metric perturbation around a cosmological background, we obtain explicit expressions for the wave equations. It is shown that the speed of the traceless mode is equal to the speed of light. An additional massive scalar mode appears in the propagation of the GWs. To find phenomena beyond the general relativity, the scalar mode mass is calculated as a function of the background curvature in some typical models.


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