Ligo_parapano

: Ongoing work for the fourth observing run includes installing A+ upgrades designed to lower fundamental noise and increase the detectors' sensitivity to gravitational waves.

For more technical details, you can refer to the comprehensive Review of the Advanced LIGO Gravitational Wave Observatories or explore the official LIGO Lab publications . ligo_parapano

: Since its first detection of colliding black holes in 2015, LIGO has transitioned into a new era of "multi-messenger" astronomy, observing events like neutron star mergers that were previously invisible to traditional telescopes. : Ongoing work for the fourth observing run

: LIGO operates two widely separated L-shaped interferometers in the United States, each with 4km-long arms. These instruments use high-power laser interferometry to measure changes in distance as small as one part in 102110 to the 21st power including quantum noise and thermal noise

: The sensitivity of these detectors is primarily limited by various "noise" sources, including quantum noise and thermal noise, which engineers are constantly working to mitigate.