pbs-space-time 9 months ago
Matt O'Dowd #Space and Time

Was the Gravitational Wave Background Finally Discovered?

A few weeks ago a large team of gravitational wave astronomers announced something pretty wild.

The moderately confident detection of pervasive ripples in the fabric of space time that presumably fills the cosmos, detected by watching for subtle connections between the signals from rapidly spinning cores of dead stars in our galactic neighborhood.


In other words, the gravitational wave background has probably been detected using a pulsar timing array.


00:00 Introduction

01:02 Relativity and Gravitational Waves

02:21 Discovering Gravitational Waves

03:49 Gravitational Waves & Pulsars

05:04 Pulsar Timing Array Discovers GWB

06:48 Understanding the GWB

07:55 Are Pulsars Seeing Gravitational Waves?

09:00 Correlated & Anti-Correlated Pulsar Rates

10:07 Hellings and Downs Curve

11:44 Binary Supermassive Black Holes

13:39 NANOgrav Frequency Spectrum

Matt O'Dowd