Correlated noise in networks of gravitationalwave detectors: Subtraction and mitigation
Abstract
One of the key science goals of advanced gravitationalwave detectors is to observe a stochastic gravitationalwave background. However, recent work demonstrates that correlated magnetic fields from Schumann resonances can produce correlated strain noise over global distances, potentially limiting the sensitivity of stochastic background searches with advanced detectors. In this paper, we estimate the correlated noise budget for the worldwide advanced detector network and conclude that correlated noise may affect upcoming measurements. We investigate the possibility of a Wiener filtering scheme to subtract correlated noise from Advanced LIGO searches, and estimate the required specifications. We also consider the possibility that residual correlated noise remains following subtraction, and we devise an optimal strategy for measuring astronomical parameters in the presence of correlated noise. Using this new formalism, we estimate the loss of sensitivity for a broadband, isotropic stochastic background search using 1 yr of LIGO data at design sensitivity. Given our current noise budget, the uncertainty with which LIGO can estimate energy density will likely increase by a factor of ≈12—if it is impossible to achieve significant subtraction. Additionally, narrow band crosscorrelation searches may be severely affected at low frequencies f ≲70 Hz without effective subtraction.
 Publication:

Physical Review D
 Pub Date:
 July 2014
 DOI:
 10.1103/PhysRevD.90.023013
 arXiv:
 arXiv:1406.2367
 Bibcode:
 2014PhRvD..90b3013T
 Keywords:

 95.55.Ym;
 Gravitational radiation detectors;
 mass spectrometers;
 and other instrumentation and techniques;
 Astrophysics  Instrumentation and Methods for Astrophysics;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 16 pages, 8 figures