摘要: Primordial gravitational waves with extremely low frequency are expected to
origin from inflation in the early Universe. The detection of such kind of
gravitational waves is of great significance to verify the inflationary theory
and determine the energy scale of inflation. B-mode of polarization of cosmic
microwave background shows to be a promising probe of extremely low frequency
primordial gravitational wave. In order to find a complementary observational
feature induced by primordial gravitational wave with extremely low frequency,
we propose an alternative way of detection by investigating the effect of
primordial gravitational wave with extremely low frequency on a gravitational
lens system with a non-aligned source-deflector-observer configuration. The
results show that, with a series of chosen parameters, gravitational lens
system with perturbation from extremely low frequency primordial gravitational
wave could induce time delay which could deviate from the time delay deduced
from theoretical model as much as about one hundred percent, meaning that
gravitational lens system with a non-aligned configuration could serve as a
potential long-base-line detector of extremely low frequency primordial
gravitational wave.