General Relativity for Pedestrians -- First 6 lectures (original) (raw)

MPA Lectures on Gravitational Waves in Cosmology

2018

Almost a century ago, Albert Einstein predicted the existence of gravitational waves, ripples in the spacetime, as a possible solution of the linearized general relativity. Surprisingly, shortly after that, Einstein himself changed his mind, and since after, like many other physicists of his time, he believed that they are not physical but an artifact of linearization. It was not until Herman Bondi’s 1957 Nature paper that the first mathematically precise definition of gravitational waves in the full Einstein equations has been discovered. Seventeen years later, Hulse and Taylor made the first indirect detection of this mysterious waves. And finally, in another historic event, only three years ago, these waves were first detected directly by LIGO. Apart from the astrophysical gravitational waves, a stochastic background of relic gravitational waves is also highly expected. These tensor perturbations are the only missing (key) prediction of the inflation paradigm which has not been d...

Gravitational Waves Notes, Issue #2

2010

GW Notes was born from the need for a journal where the distinct communities involved in gravitation wave research might gather. While these three communities - Astrophysics, General Relativity and Data Analysis - have made significant collaborative progress over recent years, we believe that it is indispensable to future advancement that they draw closer, and that they speak a common

**FULL TITLE** ASP Conference Series, Vol. **VOLUME**, **YEAR OF PUBLICATION** **NAMES OF EDITORS** The New Science of Gravitational Waves

2007

A brief survey is presented of new science that will emerge during the decades ahead from direct detection of gravitational radiation. Interferometers on earth and in space will probe the universe in an entirely new way by directly sensing motions of distant matter over a range of more than a million in frequency. The most powerful sources of gravitational (or indeed any form of) energy in the universe are inspiralling and merging binary black holes; with LISA data, they will become the most distant, most completely and precisely modeled, and most accurately measured systems in astronomy outside the solar system. Other sources range from already known and named nearby Galactic binary stars, to compact objects being swallowed by massive black holes, to possible effects of new physics: phase transitions and superstrings from the early universe, or holographic noise from quantum fluctuations of local spacetime.

Workshop on gravitational waves

1996

In this article we summarise the proceedings of the Workshop on Gravitational Waves held during ICGC-95. In the first part we present the discussions on 3PN calculations (L. Blanchet, P. Jaranowski), black hole perturbation theory (M. Sasaki, J. Pullin), numerical relativity (E. Seidel), data analysis (B.S. Sathyaprakash), detection of gravitational waves from pulsars (S. Dhurandhar), and the limit on rotation of relativistic stars (J. Friedman). In the second part we briefly discuss the contributed papers which were mainly on detectors and detection techniques of gravitational waves.

Black holes, gravitational waves and fundamental physics: a roadmap

The grand challenges of contemporary fundamental physics---dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem---all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress.

Gravitational Waves

Einstein proposed his 'General Theory of Relativity' in 1915. Along with the unparalleled excellence of imagination and intellect, GTR predicted many Gravitational Phenomenon which could otherwise never arise in the Newtonian Theory. The precession of the perihelia of Mercury, bending of light near massive objects and gravitational red-shift being some of the consequences of the proposed space-time curvature, were successfully verified in the days to come. Among others GTR predicted the existence of Gravitation Waves, ripples in the curved space-time as a consequence of abrupt disturbances in the mass configuration. Though the theory present a bold claim of their existence, there has been no direct detection till date. In this term-paper we discuss in brief the reasons and properties of Gravitational Waves.

Astro2020 science white paper: The gravitational wave view of massive black holes

arXiv: Astrophysics of Galaxies, 2019

Coalescing, massive black-hole (MBH) binaries are the most powerful sources of gravitational waves (GWs) in the Universe, which makes MBH science a prime focus for ongoing and upcoming GW observatories. The Laser Interferometer Space Antenna (LISA) -- a gigameter scale space-based GW observatory -- will grant us access to an immense cosmological volume, revealing MBHs merging when the first cosmic structures assembled in the Dark Ages. LISA will unveil the yet unknown origin of the first quasars, and detect the teeming population of MBHs of 104−10710^4 - 10^7104107 solar masses. forming within protogalactic halos. The Pulsar Timing Array, a galactic-scale GW survey, can access the largest MBHs the Universe, detecting the cosmic GW foreground from inspiraling MBH binaries of about 10^9 solar masses. LISA can measure MBH spins and masses with precision far exceeding that from electromagnetic (EM) probes, and together, both GW observatories will provide the first full census of binary MBHs, and t...