scholarly journals Modern General Relativity: Black Holes, Gravitational Waves, and Cosmology to take you through the ripples of space-time

2019 ◽  
Vol 64 (17) ◽  
pp. 1763-1764
Author(s):  
Yang Sun
2018 ◽  
pp. 106-109
Author(s):  
Alvaro De Rújula

Gravitational waves emitted by black hole mergers. The first LIGO event: GW150917, the coalescence of two black holes of twenty nine and thirty six solar masses into one of “only” sixty two. The remaining three solar masses were emitted as energy in gravitational waves, a gigantic and perfect storm in the fabric of space-time. This is the dawn of a new era: The opening of the third “window” through which to look at the sky. Yet another triumph of general relativity. How much progress astrophysics has made since my time as a student.


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.


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.


2011 ◽  
Author(s):  
Nora Bretón ◽  
Luis Arturo Ureña-López ◽  
Hugo Aurelio Morales-Técotl ◽  
Román Linares-Romero ◽  
Elí Santos-Rodríguez ◽  
...  

2016 ◽  
Vol 31 (4) ◽  
pp. 464-492 ◽  
Author(s):  
Stefan Helmreich

In February 2016, U.S.-based astronomers announced that they had detected gravitational waves, vibrations in the substance of space-time. When they made the detection public, they translated the signal into sound, a “chirp,” a sound wave swooping up in frequency, indexing, scientists said, the collision of two black holes 1.3 billion years ago. Drawing on interviews with gravitational-wave scientists at MIT and interpreting popular representations of this cosmic audio, I ask after these scientists’ acoustemology—that is, what the anthropologist of sound Steven Feld would call their “sonic way of knowing and being.” Some scientists suggest that interpreting gravitational-wave sounds requires them to develop a “vocabulary,” a trained judgment about how to listen to the impress of interstellar vibration on the medium of the detector. Gravitational-wave detection sounds, I argue, are thus articulations of theories with models and of models with instrumental captures of the cosmically nonhuman. Such articulations, based on mathematical and technological formalisms—Einstein’s equations, interferometric observatories, and sound files—operate alongside less fully disciplined collections of acoustic, auditory, and even musical metaphors, which I call informalisms. Those informalisms then bounce back on the original articulations, leading to rhetorical reverb, in which articulations—amplified through analogies, similes, and metaphors—become difficult to fully isolate from the rhetorical reflections they generate. Filtering analysis through a number of accompanying sound files, this article contributes to the anthropology of listening, positing that scientific audition often operates by listening through technologies that have been tuned to render theories and their accompanying formalisms both materially explicit and interpretively resonant.


Author(s):  
W. F. Chagas-Filho

Loop Quantum Gravity is a theory that attempts to describe the quantum mechanics of the gravitational field based on the canonical quantization of General Relativity. According to Loop Quantum Gravity, in a gravitational field, geometric quantities such as area and volume are quantized in terms of the Planck length. In this paper we present the basic ideas for a future, mathematically more rigorous, attempt to combine black holes and gravitational waves using the quantization of geometric quantities introduced by Loop Quantum Gravity.


Author(s):  
Charles D. Bailyn

This chapter looks at the detection of black holes through gravitational waves. While further improvements can be expected in the ability to detect and measure electromagnetic radiation, it is possible that the next great advances in observational astrophysics will come from the detection of other kinds of information altogether. Currently, there is a great excitement about the possibility of directly detecting an entirely new “celestial messenger,” namely, gravitational radiation. The existence of gravitational waves is a prediction of general relativity, and current technology is very close to being able to detect them directly. The strongest sources of gravitational radiation are expected to be merging black holes. Since such mergers are expected to occur, both between stellar-mass and supermassive black holes, the detection of gravitational radiation would provide a new way not only to explore gravitational physics but also to look for and to study celestial black holes.


2009 ◽  
Vol 18 (14) ◽  
pp. 2221-2229 ◽  
Author(s):  
R. MAIER ◽  
I. DAMIÃO SOARES

The dynamics of gravitational collapse is examined in the realm of string-based formalism of D-branes which encompasses general relativity as a low energy limit. A complete analytical solution is given to the spherically symmetric collapse of a pure dust star, including its matching with a corrected Schwarzschild exterior space–time. The collapse forms a black hole (an exterior event horizon) enclosing not a singularity but perpetually bouncing matter in the infinite chain of space–time maximal analytical extensions inside the outer event horizon. This chain of analytical extensions has a structure analogous to that of the Reissner–Nordstrom solution. The interior trapped bouncing matter has the possibility of being expelled by disruptive nonlinear resonance mechanisms.


2021 ◽  
Vol 103 (4) ◽  
Author(s):  
Erik Wessel ◽  
Vasileios Paschalidis ◽  
Antonios Tsokaros ◽  
Milton Ruiz ◽  
Stuart L. Shapiro

Universe ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. 137
Author(s):  
Andrzej Królak ◽  
Paritosh Verma

In this paper we present the most recent observations of gravitational waves (GWs) by LIGO and Virgo detectors. We also discuss contributions of the recent Nobel prize winner, Sir Roger Penrose to understanding gravitational radiation and black holes (BHs). We make a short introduction to GW phenomenon in general relativity (GR) and we present main sources of detectable GW signals. We describe the laser interferometric detectors that made the first observations of GWs. We briefly discuss the first direct detection of GW signal that originated from a merger of two BHs and the first detection of GW signal form merger of two neutron stars (NSs). Finally we present in more detail the observations of GW signals made during the first half of the most recent observing run of the LIGO and Virgo projects. Finally we present prospects for future GW observations.


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