The stochastic background of gravitational waves
is noise, produced by a high number of uncorrelated events.

It may be of cosmological origin or of
astrophysical origin.

The sensitivity of the detectors
to this background is a function of

their noise spectral amplitude (1/sqrt(Hz))
and of the square root of observation time and frequency bandwidth
.

At least two detectors, properly located and aligned, are needed
to do a measure.

Read this note on the
stochastic g.w. search !

We have done a
crosscorrelation analysis of the data recorded by the gravitational
wave (g.w.) resonant detectors Explorer and Nautilus, to obtain
information on the g.w. stochastic background. We have found that
the quantity

The procedure and the
results have been published (Astronomy Astroph. 351,811-814 (1999))
and

this is the PDF
file and this
is Fig.1 this
is Fig. 2

Another paper on results obtained using the data of Explorer and
Nautilus is: "Upper limit for g.w. stochastic background with the
Explorer and Nautilus resonant detectors" (Physics Letters B 385
(1996))

click
here !

Papers describing the analysis
procedures and the limit we may reach are in:

Stochastic
background of g.w. (2000, Proc. GWDAW Rome)

Resonant
antennas for stochastic background measurements (CQG,1997)

Spectral
tecqniques for stochastic background measurements (1997, Proc.
GWDAW, Orsay)